ALBERT

Description:    This study examines the Indian summer monsoon hydroclimate in the National Centers for Environmental Prediction (NCEP)-Department of Energy (DOE) Reanalysis (R2), the Climate Forecast System Reanalysis (CFSR), and the Modern Era Retrospective-Analysis for Research and Applications (MERRA). The three reanalyses show significant differences in the climatology of evaporation, low-level winds, and precipitable water fields over India. For example, the continental evaporation is significantly less in CFSR compared to R2 and MERRA. Likewise the mean boreal summer 925 hPa westerly winds in the northern Indian Ocean are stronger in R2. Similarly the continental precipitable water in R2 is much less while it is higher and comparable in MERRA and CFSR. Despite these climatological differences between the reanalyses, the climatological evaporative sources for rain events over central India show some qualitative similarities. Major differences however appear when interannual variations of the Indian summer monsoon are analyzed. The anomalous oceanic sources of moisture from the adjacent Bay of Bengal and Arabian Sea play a significant role in determining the wet or dry year of the Indian monsoon in CFSR. However in R2 the local evaporative sources from the continental region play a more significant role. We also find that the interannual variability of the evaporative sources in the break spells of the intraseasonal variations of the Indian monsoon is stronger than in the wet spells. We therefore claim that instead of rainfall, evaporative sources may be a more appropriate metric to observe the relationship between the seasonal monsoon strength and intraseasonal activity. These findings are consistent across the reanalyses and provide a basis to improve the predictability of intraseasonal variability of the Indian monsoon. This study also has a bearing on improving weather prediction for tropical cyclones in that we suggest targeting enhanced observations in the Bay of Bengal (where it is drawing the most moisture from) for improved analysis during active spells of the intraseasonal variability of the Indian monsoon. The analysis suggests that the land–atmosphere interactions contribute significant uncertainty to the Indian monsoon in the reanalyses, which is consistent with the fact that most of the global reanalyses do not assimilate any land-surface data because the data are not available. Therefore, the land–atmosphere interaction in the reanalyses is highly dependent on the land-surface model and it’s coupling with the atmospheric model. Content Type Journal Article Pages 1-20 DOI 10.1007/s00382-012-1319-y Authors Vasubandhu Misra, Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL, USA P. Pantina, Science Systems and Application, Inc., 10210 Greenbelt Road, Ste. 600, Lanham, MD 20706, USA S. C. Chan, School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, UK S. DiNapoli, Center for Ocean-Atmospheric Prediction Studies, Florida State University, Tallahassee, FL, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    This work uses a WRF numerical simulation from 1960 to 2005 performed at a high horizontal resolution (2 km) to analyze the surface wind variability over a complex terrain region located in northern Iberia. A shorter slice of this simulation has been used in a previous study to demonstrate the ability of the WRF model in reproducing the observed wind variability during the period 1992–2005. Learning from that validation exercise, the extended simulation is herein used to inspect the wind behavior where and when observations are not available and to determine the main synoptic mechanisms responsible for the surface wind variability. A principal component analysis was applied to the daily mean wind. Two principal modes of variation accumulate a large percentage of the wind variability (83.7%). The first mode reflects the channeling of the flow between the large mountain systems in northern Iberia modulated by the smaller topographic features of the region. The second mode further contributes to stress the differentiated wind behavior over the mountains and valleys. Both modes show significant contributions at the higher frequencies during the whole analyzed period, with different contributions at lower frequencies during the different decades. A strong relationship was found between these two modes and the zonal and meridional large scale pressure gradients over the area. This relationship is described in the context of the influence of standard circulation modes relevant in the European region like the North Atlantic Oscillation, the East Atlantic pattern, East Atlantic/Western Russia pattern, and the Scandinavian pattern. Content Type Journal Article Pages 1-14 DOI 10.1007/s00382-012-1326-z Authors Pedro A. Jiménez, Departamento de Astrofísica y CC, de la Atmósfera, Faculatad de CC, Físicas, UCM, Avenida Complutense s/n, 28040 Madrid, Spain J. Fidel González-Rouco, Departamento de Astrofísica y CC, de la Atmósfera, Faculatad de CC, Físicas, UCM, Avenida Complutense s/n, 28040 Madrid, Spain Juan P. Montávez, Departamento de Física, Universidad de Murcia, Murcia, Spain E. García-Bustamante, Department of Geography, Justus-Liebig University of Giessen, Giessen, Germany J. Navarro, División de Energías Renovables, CIEMAT, 28040 Madrid, Spain J. Dudhia, Mesoscale and Microscale Meteorology Division, NCAR, Boulder, CO, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The water vapour feedback probably makes the largest contribution to climate sensitivity, and the second-largest contribution to its uncertainty, in the sense of disagreement between General Circulation Models (GCMs, the most physically detailed models of climate we have). Yet there has been no quantification of it which allows these differences to be attributed physically with the aim of constraining the true value. This paper develops a new breakdown of the non-cloud LW (longwave) response to climate change, which avoids the problems of the conventional breakdown, and applies it to a set of 4 GCMs. The basic physical differences are that temperature is used as the vertical coordinate, and relative humidity as the humidity variable. In this framework the different GCMs’ feedbacks look more alike, consistent with our understanding that their water vapour responses are physically very similar. Also, in the global mean all the feedback components have the same sign, allowing us to conveniently attribute the overall response fractionally (e.g. about 60% from the “partly-Simpsonian” component). The systematic cancellation between different feedback components in the conventional breakdown is lost, so now a difference in a feedback component actually contributes to a difference in climate sensitivity, and the differences between these GCMs in the non-cloud LW part of this can be traced to differences in formulation, mean climate and climate change response. Physical effects such as those due to variations in the formulation of LW radiative transfer become visible. Differences in the distribution of warming no longer dominate comparison of GCMs. The largest component depends locally only on the GCM’s mean climate, so it can in principle be calculated for the real world and validated. However, components dependent on the climate change response probably account for most of the variation between GCMs. The effect of simply changing the humidity variable in the conventional breakdown is also examined. It gives some of this improvement—the loss of the cancellations that leave the conventional breakdown of no use to understand differences between GCMs’ climate sensitivities—but not the link to mean climate. Content Type Journal Article Pages 1-12 DOI 10.1007/s00382-012-1294-3 Authors William Ingram, Atmospheric, Oceanic and Planetary Physics, Department of Physics, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU UK Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Climate change has the potential to be a source of increased variability if crops are more frequently exposed to damaging weather conditions. Yield variability could respond to a shift in the frequency of extreme events to which crops are susceptible, or if weather becomes more variable. Here we focus on the United States, which produces about 40% of the world’s maize, much of it in areas that are expected to see increased interannual variability in temperature. We combine a statistical crop model based on historical climate and yield data for 1950–2005 with temperature and precipitation projections from 15 different global circulation models. Holding current growing area constant, aggregate yields are projected to decrease by an average of 18% by 2030–2050 relative to 1980–2000 while the coefficient of variation of yield increases by an average of 47%. Projections from 13 out of 15 climate models result in an aggregate increase in national yield coefficient of variation, indicating that maize yields are likely to become more volatile in this key growing region without effective adaptation responses. Rising CO 2 could partially dampen this increase in variability through improved water use efficiency in dry years, but we expect any interactions between CO 2 and temperature or precipitation to have little effect on mean yield changes. Content Type Journal Article Category Letter Pages 1-9 DOI 10.1007/s10584-012-0428-2 Authors Daniel Urban, Environmental Earth System Science, Center on Food Security and the Environment, Stanford University, Stanford, CA, USA Michael J. Roberts, Department of Agricultural and Resource Economics, North Carolina State University, Raleigh, NC, USA Wolfram Schlenker, Department of Economics and School of International and Public Affairs, Columbia University, New York, NY, USA David B. Lobell, Environmental Earth System Science, Center on Food Security and the Environment, Stanford University, Stanford, CA, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Climate change as a global problem has moved relatively swiftly into high profile political debates over the last 20 years or so, with a concomitant diffusion from the natural sciences into the social sciences. The study of the human dimensions of climate change has been growing in momentum through research which attempts to describe, evaluate, quantify and model perceptions of climate change, understand more about risk and assess the construction of policy. Cultural geographers’ concerns with the construction of knowledge, the workings of social relations in space and the politics and poetics of place-based identities provide a lens through which personal, collective and institutional responses to climate change can be evaluated using critical and interpretative methodologies. Adopting a cultural geography approach, this paper examines how climate change as a particular environmental discourse is constructed through memory, observation and conversation, as well as materialised in farming practices on the Lizard Peninsula, Cornwall, UK. Content Type Journal Article Pages 1-12 DOI 10.1007/s10584-012-0417-5 Authors Hilary Geoghegan, Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK Catherine Leyson, Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    The Eastern Mediterranean and the Middle East (EMME) are likely to be greatly affected by climate change, associated with increases in the frequency and intensity of droughts and hot weather conditions. Since the region is diverse and extreme climate conditions already common, the impacts will be disproportional. We have analyzed long-term meteorological datasets along with regional climate model projections for the 21st century, based on the intermediate IPCC SRES scenario A1B. This suggests a continual, gradual and relatively strong warming of about 3.5–7°C between the 1961–1990 reference period and the period 2070–2099. Daytime maximum temperatures appear to increase most rapidly in the northern part of the region, i.e. the Balkan Peninsula and Turkey. Hot summer conditions that rarely occurred in the reference period may become the norm by the middle and the end of the 21st century. Projected precipitation changes are quite variable. Annual precipitation is expected to decrease in the southern Europe – Turkey region and the Levant, whereas in the Arabian Gulf area it may increase. In the former region rainfall is actually expected to increase in winter, while decreasing in spring and summer, with a substantial increase of the number of days without rainfall. Anticipated regional impacts of climate change include heat stress, associated with poor air quality in the urban environment, and increasing scarcity of fresh water in the Levant. Content Type Journal Article Pages 1-21 DOI 10.1007/s10584-012-0418-4 Authors J. Lelieveld, The Cyprus Institute, P.O. Box 27456, 1645 Nicosia, Cyprus P. Hadjinicolaou, The Cyprus Institute, P.O. Box 27456, 1645 Nicosia, Cyprus E. Kostopoulou, The Cyprus Institute, P.O. Box 27456, 1645 Nicosia, Cyprus J. Chenoweth, University of Surrey, Guildford, Surrey, UK GU2 7XH M. El Maayar, The Cyprus Institute, P.O. Box 27456, 1645 Nicosia, Cyprus C. Giannakopoulos, National Observatory of Athens, 15236 Athens, Greece C. Hannides, The Cyprus Institute, P.O. Box 27456, 1645 Nicosia, Cyprus M. A. Lange, The Cyprus Institute, P.O. Box 27456, 1645 Nicosia, Cyprus M. Tanarhte, The Cyprus Institute, P.O. Box 27456, 1645 Nicosia, Cyprus E. Tyrlis, The Cyprus Institute, P.O. Box 27456, 1645 Nicosia, Cyprus E. Xoplaki, The Cyprus Institute, P.O. Box 27456, 1645 Nicosia, Cyprus Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    This work analyzes variations of snow water with elevation for a group of AR4 models over the Western United States. The results are expressed in terms of both snow water equivalent (SWE), which is the depth of snow if melted, and snow water volume (SWV), which is the total volume of SWE for a specified region. The decrease in total SWV over the study region between 1905 and 25 and 1980–99 is about 22%, which is in the range of the observed values. The results for both the A1b and B1 scenarios for the middle twenty-first century both show a near total loss of SWE at lower elevations. However, the largest losses for SWV are near 1800 m. Furthermore, the total SWV loss for the A1b scenario is about 63%, whereas that for the more moderate B1 scenario is about 49%. Thus, a reduction of greenhouse gas emissions is likely to reduce the loss of snow, which is vital to society in the dry Western United States. Content Type Journal Article Pages 1-11 DOI 10.1007/s10584-011-0258-7 Authors Bryan C. Weare, Atmospheric Science Program, Department of Land, Air and Water Resources, University of California, Davis, Davis, CA, USA Brice Blossier, Atmospheric Science Program, Department of Land, Air and Water Resources, University of California, Davis, Davis, CA, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Methane emissions contribute to global baseline surface ozone concentrations; therefore reducing methane to address climate change has significant co-benefits for air quality and human health. We analyze the costs of reducing methane from 2005 to 2030, as might be motivated to reduce climate forcing, and the resulting benefits from lower surface ozone to 2060. We construct three plausible scenarios of methane emission reductions, relative to a base scenario, ranging from 75 to 180 Mton CH 4 yr −1 decreased in 2030. Using compilations of the global availability of methane emission reductions, the least aggressive scenario (A) does not incur any positive marginal costs to 2030, while the most aggressive (C) requires discovery of new methane abatement technologies. The present value of implementation costs for Scenario B are nearly equal to Scenario A, as it implements cost-saving options more quickly, even though it adopts positive cost measures. We estimate the avoided premature human mortalities due to surface ozone decreases by combining transient full-chemistry simulations of these scenarios in a global atmospheric chemical transport model, with concentration-mortality relationships from a short-term epidemiologic study and projected global population. An estimated 38,000 premature mortalities are avoided globally in 2030 under Scenario B. As benefits of methane reduction are positive but costs are negative for Scenario A, it is justified regardless of how avoided mortalities are valued. The incremental benefits of Scenario B also far outweigh the incremental costs. Scenario C has incremental costs that roughly equal benefits, only when technological learning is assumed. Benefits within industrialized nations alone also exceed costs in Scenarios A and B, assuming that the lowest-cost emission reductions, including those in developing nations, are implemented. Monetized co-benefits of methane mitigation for human health are estimated to be $13–17 per ton CO 2 eq, with a wider range possible under alternative assumptions. Methane mitigation can be a cost-effective means of long-term and international air quality management, with concurrent benefits for climate. Content Type Journal Article Pages 1-21 DOI 10.1007/s10584-012-0426-4 Authors J. Jason West, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, CB#7431, Chapel Hill, NC 27599, USA Arlene M. Fiore, Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration, 201 Forrestal Road, Princeton, NJ 08540, USA Larry W. Horowitz, Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration, 201 Forrestal Road, Princeton, NJ 08540, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    In this paper, we analyze the standardized anomalies of land surface temperature (LST) retrieved from the Special Sensor Microwave Imager (SSM/I) vertically polarized 37 GHz ( ) brightness temperature over the Tibetan Plateau for the period 1987 to 2008. A radiative transfer model is used to derive LST from SSM/I , which is calibrated and validated using time series of field measured soil surface temperatures. Additional Plateau-scale verification is performed with monthly LST products from the Moderate Resolution Imaging Spectroradiometer, the Noah land surface model and air temperature measured by Chinese Meteorological Administration. Trend analysis shows that the annual and monthly standardized anomalies are increasing at an averaged rate of 0.5 decade  − 1 . The highest positive trends are noted over the central part of the Plateau, which is on average 0.80 decade  − 1 with a maximum of 1.44 decade  − 1 . Conversely, a negative trend in the anomalies is found for the Taklamakan desert and the Himalayan foothills with a rate of −0.27 decade  − 1 and reaching a maximum of −1.4 decade  − 1 . In addition, we find that LST anomaly trends on the Plateau are seasonally dependent and increase with the elevation. These observed trends are in agreement with previous studies conducted with in-situ measurements, which demonstrates the use of long-term earth observation programmes for climate studies as has also been articulated in the 2007 IPCC report. Content Type Journal Article Pages 1-13 DOI 10.1007/s10584-012-0427-3 Authors Mhd. Suhyb Salama, ITC, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands Rogier Van der Velde, ITC, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands Lei Zhong, Institute of Tibetan Plateau Research, Chinese Academy of Science (ITP/CAS), Beijing, People’s Republic of China Yaoming Ma, Institute of Tibetan Plateau Research, Chinese Academy of Science (ITP/CAS), Beijing, People’s Republic of China Matthew Ofwono, ITC, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands Zhongbo Su, ITC, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    The MJO modulation of sea surface chlorophyll-a (Chl) examined initially by Waliser et al. in Geophys Res Lett, ( 2005 ) is revisited with a significantly longer time-series of observations and a more systematic approach to characterizing the possible mechanisms underlying the MJO-Chl relationships. The MJO composite analysis of Chl and lead-lag correlations between Chl and other physical variables reveal regional variability of Chl and corresponding indicative temporal relationships among variables. Along the path of the MJO convection, wind speed—a proxy for oceanic vertical turbulent mixing and corresponding entrainment—is most strongly correlated with Chl when wind leads Chl by a few days. Composite Chl also displays MJO influences away from the path of the MJO convection. The role of wind speed in those regions is generally the same for Chl variability as that along the path of the MJO convection, although Ekman pumping also plays a role in generating Chl variability in limited regions. However, the wind forcing away from the MJO convection path is less coherent, rendering the temporal link relatively weak. Lastly, the potential for bio-physical feedbacks at the MJO time-scale is examined. The correlation analysis provides tantalizing evidence for local bio-feedbacks to the physical MJO system. Plausible hypothesis for Chl to amplify the MJO phase transition is presented though it cannot be affirmed in this study and will be examined and reported in a future modeling study. Content Type Journal Article Pages 1-20 DOI 10.1007/s00382-012-1321-4 Authors Daeho Jin, Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA Duane E. Waliser, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA Charles Jones, Earth Research Institute, University of California, Santa Barbara, CA, USA Raghu Murtugudde, Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    A principal component decomposition of monthly sea surface temperature (SST) variability in the tropical Pacific Ocean demonstrates that nearly all of the linear trends during 1950–2010 are found in two leading patterns. The first SST pattern is strongly related to the canonical El Niño-Southern Oscillation (ENSO) pattern. The second pattern shares characteristics with the first pattern and its existence solely depends on the presence of linear trends across the tropical Pacific Ocean. The decomposition also uncovers a third pattern, often referred to as ENSO Modoki, but the linear trend is small and dataset dependent over the full 61-year record and is insignificant within each season. ENSO Modoki is also reflected in the equatorial zonal SST gradient between the Niño-4 region, located in the west-central Pacific, and the Niño-3 region in the eastern Pacific. It is only in this zonal SST gradient that a marginally significant trend arises early in the Northern Hemisphere spring (March–May) during El Niño and La Niña and also in the late summer (July–September) during El Niño. Yet these SST trends in the zonal gradient do not unequivocally represent an ENSO Modoki-like dipole because they are exclusively associated with significant positive SST trends in either the eastern or western Pacific, with no corresponding significant negative trends. Insignificant trends in the zonal SST gradient are evident during the boreal wintertime months when ENSO events typically mature. Given the presence of positive SST trends across much of the equatorial Pacific Ocean, using fixed SST anomaly thresholds to define ENSO events likely needs to be reconsidered. Content Type Journal Article Pages 1-14 DOI 10.1007/s00382-012-1331-2 Authors Michelle L. L’Heureux, NOAA Climate Prediction Center, 5200 Auth Rd, Rm 605, Camp Springs, MD 20746, USA Dan C. Collins, NOAA Climate Prediction Center, 5200 Auth Rd, Rm 605, Camp Springs, MD 20746, USA Zeng-Zhen Hu, NOAA Climate Prediction Center, 5200 Auth Rd, Rm 605, Camp Springs, MD 20746, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    ‘Scepticism’ in public attitudes towards climate change is seen as a significant barrier to public engagement. In an experimental study, we measured participants’ scepticism about climate change before and after reading two newspaper editorials that made opposing claims about the reality and seriousness of climate change (designed to generate uncertainty). A well-established social psychological finding is that people with opposing attitudes often assimilate evidence in a way that is biased towards their existing attitudinal position, which may lead to attitude polarisation . We found that people who were less sceptical about climate change evaluated the convincingness and reliability of the editorials in a markedly different way to people who were more sceptical about climate change, demonstrating biased assimilation of the information. In both groups, attitudes towards climate change became significantly more sceptical after reading the editorials, but we observed no evidence of attitude polarisation— that is, the attitudes of these two groups did not diverge. The results are the first application of the well-established assimilation and polarisation paradigm to attitudes about climate change, with important implications for anticipating how uncertainty—in the form of conflicting information—may impact on public engagement with climate change. Content Type Journal Article Pages 1-16 DOI 10.1007/s10584-012-0424-6 Authors Adam Corner, School of Psychology, Cardiff University, Affiliate of the BRASS Centre, Cardiff University & Tyndall Centre for Climate Change Research, Tower Building, Park Place, Cardiff CF10 3AT, UK Lorraine Whitmarsh, School of Psychology, Cardiff University, Affiliate of the BRASS Centre, Cardiff University & Tyndall Centre for Climate Change Research, Tower Building, Park Place, Cardiff CF10 3AT, UK Dimitrios Xenias, School of Psychology, Cardiff University, Affiliate of the BRASS Centre, Cardiff University & Tyndall Centre for Climate Change Research, Tower Building, Park Place, Cardiff CF10 3AT, UK Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    The impact of climate warming on the upper layer of the Bering Sea is investigated by using a high-resolution coupled global climate model. The model is forced by increasing atmospheric CO 2 at a rate of 1% per year until CO 2 reaches double its initial value (after 70 years), after which it is held constant. In response to this forcing, the upper layer of the Bering Sea warms by about 2°C in the southeastern shelf and by a little more than 1°C in the western basin. The wintertime ventilation to the permanent thermocline weakens in the western Bering Sea. After CO 2 doubling, the southeastern shelf of the Bering Sea becomes almost ice-free in March, and the stratification of the upper layer strengthens in May and June. Changes of physical condition due to the climate warming would impact the pre-condition of spring bio-productivity in the southeastern shelf. Content Type Journal Article Pages 1-14 DOI 10.1007/s00382-012-1301-8 Authors Hyun-Chul Lee, Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA Thomas L. Delworth, Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA Anthony Rosati, Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA Rong Zhang, Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA Whit G. Anderson, Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA Fanrong Zeng, Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA Charles A. Stock, Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA Anand Gnanadesikan, Johns Hopkins University, Baltimore, MD, USA Keith W. Dixon, Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA Stephen M. Griffies, Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    We present an approach to assess and compare risk from climate change among multiple species through a risk matrix, in which managers can quickly prioritize for species that need to have strategies developed, evaluated further, or watched. We base the matrix upon earlier work towards the National Climate Assessment for potential damage to infrastructures from climate change. Risk is defined here as the product of the likelihood of an event occurring and the consequences or impact of that event. In the context of species habitats, the likelihood component is related to the potential changes in suitable habitat modeled at various times during this century. Consequences are related to the adaptability of the species to cope with the changes, especially the increasing intensity and/or frequency of disturbance events that are projected. We derived consequence scores from nine biological and 12 disturbance characteristics that were pulled from literature for each species. All data were generated from an atlas of climate change for 134 trees of the eastern United States ( www.nrs.fs.fed.us/atlas ). We show examples which depict a wide range of risk for tree species of northern Wisconsin, including species that may gain substantial habitat as well as lose substantial habitat, both of which will require the development of strategies to help the ecosystems adapt to such changes. Content Type Journal Article Pages 1-13 DOI 10.1007/s10584-012-0412-x Authors Louis R. Iverson, Northern Research Station, U.S. Forest Service, 359 Main Road, Delaware, OH 43015, USA Stephen N. Matthews, Northern Research Station, U.S. Forest Service, 359 Main Road, Delaware, OH 43015, USA Anantha M. Prasad, Northern Research Station, U.S. Forest Service, 359 Main Road, Delaware, OH 43015, USA Matthew P. Peters, Northern Research Station, U.S. Forest Service, 359 Main Road, Delaware, OH 43015, USA Gary Yohe, Wesleyan University, Middletown, CT, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    This paper conducts an empirical analysis of the factors affecting U.S. public concern about the threat of climate change between January 2002 and December 2010. Utilizing Stimson’s method of constructing aggregate opinion measures, data from 74 separate surveys over a 9-year period are used to construct quarterly measures of public concern over global climate change. We examine five factors that should account for changes in levels of concern: 1) extreme weather events, 2) public access to accurate scientific information, 3) media coverage, 4) elite cues, and 5) movement/countermovement advocacy. A time-series analysis indicates that elite cues and structural economic factors have the largest effect on the level of public concern about climate change. While media coverage exerts an important influence, this coverage is itself largely a function of elite cues and economic factors. Weather extremes have no effect on aggregate public opinion. Promulgation of scientific information to the public on climate change has a minimal effect. The implication would seem to be that information-based science advocacy has had only a minor effect on public concern, while political mobilization by elites and advocacy groups is critical in influencing climate change concern. Content Type Journal Article Pages 1-20 DOI 10.1007/s10584-012-0403-y Authors Robert J. Brulle, Department of Culture and Communications, Drexel University, Philadelphia, PA 19104, USA Jason Carmichael, Department of Sociology, McGill University, Montreal, Canada J. Craig Jenkins, Department of Sociology, Ohio State University, Columbus, OH, Canada Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Surface temperatures are projected to increase 3–4°C over much of Africa by the end of the 21st century. Precipitation projections are less certain, but the most plausible scenario given by the Intergovernmental Panel on Climate Change (IPCC) is that the Sahel and East Africa will experience modest increases (~5%) in precipitation by the end of the 21st century. Evapotranspiration (E a ) is an important component of the water, energy, and biogeochemical cycles that impact several climate properties, processes, and feedbacks. The interaction of E a with climate change drivers remains relatively unexplored in Africa. In this paper, we examine the trends in E a , precipitation (P), daily maximum temperature (T max ), and daily minimum temperature (T min ) on a seasonal basis using a 31 year time series of variable infiltration capacity (VIC) land surface model (LSM) E a . The VIC model captured the magnitude, variability, and structure of observed runoff better than other LSMs and a hybrid model included in the analysis. In addition, we examine the inter-correlations of E a , P, T max , and T min to determine relationships and potential feedbacks. Unlike many IPCC climate change simulations, the historical analysis reveals substantial drying over much of the Sahel and East Africa during the primary growing season. In the western Sahel, large increases in daily maximum temperature appear linked to E a declines, despite modest rainfall recovery. The decline in E a and latent heating in this region could lead to increased sensible heating and surface temperature, thus establishing a possible positive feedback between E a and surface temperature. Content Type Journal Article Pages 1-17 DOI 10.1007/s00382-012-1299-y Authors Michael Marshall, Department of Geography, Climate Hazards Group, University of California Santa Barbara, Santa Barbara, CA, USA Christopher Funk, US Geological Survey Earth Resources Observation and Science (EROS) Center, Department of Geography, University of California Santa Barbara, Santa Barbara, CA, USA Joel Michaelsen, Department of Geography, Climate Hazards Group, University of California Santa Barbara, Santa Barbara, CA, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Articulated initially by physical scientists, the idea of anthropogenic global climate change has been subject to increasingly diverse examinations in recent years. The idea has been appropriated by economists, worked with by engineers and, more recently, scrutinised by social scientists and humanities scholars. Underlying these examinations are different, yet rarely exposed, presumptions about what kind of ‘thing’ climate is: a physical abstraction, a statistical construct, an imaginative idea. If the ontological status of climate is rarely made explicit it becomes difficult to know whether the different epistemologies used to reveal climates — and their changing properties — are appropriate. This study offers one way in which the different worlds inhabited by the idea of climate may be revealed. It does so by examining a heatwave: a powerful meteorological phenomenon one would think and one which scientific accounts of climate change tell us will become more frequent in the future. The heatwave in question occurred in July 1900 in the county of Norfolk, England. This heatwave inhabits three very different worlds: the imaginative world of L P Hartley in his novel The Go Between ; the historical world of late Victorian Norfolk; and the digital world of the climate sciences. The traces of the heatwave left in these different worlds are varied and access to them is uneven. Constructing an adequate interpretation of this singular climatic event and its meaning is challenging. The study suggests that grasping the idea of climate may be harder than we think. Climates may be ineffable. Yet the approach to the study of climate illustrated here opens up new ways of thinking about the meaning and significance of climate change. Content Type Journal Article Pages 1-17 DOI 10.1007/s10584-012-0400-1 Authors Mike Hulme, Science, Society and Sustainability (3S) Group, School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    In this study, a new approach for extracting flow-dependent empirical singular vectors (FESVs) for seasonal prediction using ensemble perturbations obtained from an ensemble Kalman filter (EnKF) assimilation is presented. Due to the short interval between analyses, EnKF perturbations primarily contain instabilities related to fast weather variability. To isolate slower, coupled instabilities that would be more suitable for seasonal prediction, an empirical linear operator for seasonal time-scales (i.e. several months) is formulated using a causality hypothesis; then, the most unstable mode from the linear operator is extracted for seasonal time-scales. It is shown that the flow-dependent operator represents nonlinear integration results better than a conventional empirical linear operator static in time. Through 20 years of retrospective seasonal predictions, it is shown that the skill of forecasting equatorial SST anomalies using the FESV is systematically improved over that using Conventional ESV (CESV). For example, the correlation skill of the NINO3 SST index using FESV is higher, by about 0.1, than that of CESV at 8-month leads. In addition, the forecast skill improvement is significant over the locations where the correlation skill of conventional methods is relatively low, indicating that the FESV is effective where the initial uncertainty is large. Content Type Journal Article Pages 1-12 DOI 10.1007/s00382-012-1302-7 Authors Yoo-Geun Ham, Global Modeling and Assimilation Office, NASA/GSFC Code 610.1, Greenbelt, MD, USA Michele M. Rienecker, Global Modeling and Assimilation Office, NASA/GSFC Code 610.1, Greenbelt, MD, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    This paper assesses future climate changes over East and South Asia using a regional climate model (RegCM4) with a 50 km spatial resolution. To evaluate the model performance, RegCM4 is driven with “perfect boundary forcing” from the reanalysis data during 1970–1999 to simulate the present day climate. The model performs well in reproducing not only the mean climate and seasonality but also most of the chosen indicators of climate extremes. Future climate changes are evaluated based on two experiments driven with boundary forcing from the European-Hamburg general climate model (ECHAM5), one for the present (1970–1999) and one for the SRES A1B future scenario (2070–2099). The model predicts an annual temperature increase of about 3°–5° (smaller over the ocean and larger over the land), and an increase of annual precipitation over most of China north of 30°N and a decrease or little change in the rest of China, India and Indochina. For temperature-related extreme indicators in the future, the model predicts a generally longer growing season, more hot days in summer, and less frost days in winter. For precipitation-related extremes, the number of days with more than 10 mm of rainfall is predicted to increase north of 30°N and decrease in the south, and the maximum five-day rainfall amount and daily intensity will increase across the whole model domain. In addition, the maximum number of consecutive dry days is predicted to increase over most of the model domain, south of 40°N. Most of the Yangtze River Basin in China stands out as “hotspots” of extreme precipitation changes, with the strongest increases of daily rain intensity, maximum five-day rain amount, and the number of consecutive dry days, suggesting increased risks of both floods and droughts. Content Type Journal Article Pages 1-17 DOI 10.1007/s10584-012-0411-y Authors Huanghe Gu, State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China Guiling Wang, Department of Civil and Environmental Engineering, University of Connecticut, Storrs, USA Zhongbo Yu, State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China Rui Mei, Department of Civil and Environmental Engineering, University of Connecticut, Storrs, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    The Atlantic meridional overturning circulation (MOC) is responsible for a climatically significant northward heat transport that is expected to decrease in response to anthropogenic global warming. Here, simulations from an ensemble of UK Met Office Hadley Centre Climate Models (HadGEM1, HadGEM2 and a 22 member perturbed physics ensemble of HadCM3-like models) are used to evaluate detection times for different MOC observing strategies. Six different detection statistics are compared, including direct observations of the MOC at two latitudes (26°N and 50°N) and several multivariate detection variables based on an optimal fingerprint of MOC change previously identified using HadCM3 (Vellinga and Wood in Geophys Res Lett 31(14):L14203, 2004 ). Using these models, and assuming perfectly observed conditions, we find no evidence to suggest that detection times would be significantly reduced by measuring the MOC at 50°N instead of (or in addition to) measurements at 26°N. Our results suggest that complementary observations of hydrographic properties in the North Atlantic may help reduce MOC detection times, but the benefits are not universal across models, nor as large as previously suggested. In addition, detection times calculated using optimal fingerprint methods are sensitive to the model-dependent estimates of covariances describing internal climate variability. This last result presents a strong case for deriving fingerprints of MOC change using dynamical/physical arguments, rather than statistical methods, in order to promote more robust results across a range of models. Content Type Journal Article Pages 1-14 DOI 10.1007/s00382-012-1306-3 Authors Christopher D. Roberts, Met Office Hadley Centre, Fitzroy Road, Exeter, EX1 3PB UK Matthew D. Palmer, Met Office Hadley Centre, Fitzroy Road, Exeter, EX1 3PB UK Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The Madden–Julian oscillation (MJO) is observed to interact with moist Kelvin waves. To understand the role of this interaction, a simple scale-interaction model is built, which describes the MJO modulation of moist Kelvin waves and the feedback from moist Kelvin waves through upscale eddy heat and momentum transfer. The backward-tilted moist Kelvin waves produce eddy momentum transfer (EMT) characterized by the lower-tropospheric westerly winds and eddy heat transfer (EHT) that warms the mid-troposphere. The EHT tends to induce the lower-tropospheric easterly winds and low pressure, which is located in front of the “westerly wind burst” induced by the EMT. Adding the eddy forcing to a neutral MJO skeleton model, we show that the EHT provides an instability source for the MJO by warming up the mid-troposphere, and the EMT offers an additional instability source by enhancing the lower-tropospheric westerly winds. The eddy forcing selects eastward propagation for the unstable mode, because it generates positive/negative eddy available potential energy for the eastward/westward modes by changing their thermal and dynamical structures. The present results show that moist Kelvin waves can provide a positive feedback to the MJO only when they are located within (or near) the convective complex (center) of the MJO. The EHT and EMT feedback works positively in the front and rear part of the MJO, respectively. These theoretical results suggest the potential importance of moist Kelvin waves in sustaining the MJO and encourage further observations to document the relationship between moist Kelvin waves and the MJO. Content Type Journal Article Pages 1-12 DOI 10.1007/s00382-011-1281-0 Authors Fei Liu, International Pacific Research Center, University of Hawaii at Manoa, Honolulu, HI, USA Bin Wang, International Pacific Research Center, University of Hawaii at Manoa, Honolulu, HI, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    This paper studies temperature evolution in the city of Sfax (Middle Eastern Tunisia, with more than 600 000 people) from 1950 to 2007. Daily maximum and minimum temperatures recorded at Sfax observatory from 1950 to 2007 are analysed by studying their homogeneity, possible trends and their statistical significance. Linear regression, Student and Mann–Kendall trend test were applied to annual mean minimum and maximum temperature data to determine the existence and significance of trends. Using a number of statistical tests, it is found that the data measured at the surface station represent a non homogenous time-series. Furthermore, mean annual and monthly temperatures are evaluated and a statistically significant trend starting from year 1950 was found. Important increase of the surface temperature in the City of Sfax was found after 1984. The increase in the surface temperature in the city of Sfax is further associated with global, regional (e.g. Mediterranean area) and meso-scale temperature increase. In addition, the spatial pattern of surface temperature in the city of Sfax from 1982 to 2007 shows that the overall land surface temperature increased with the expansion of Urban Heat Island (UHI) from urban areas to suburban districts. Content Type Journal Article Pages 1-18 DOI 10.1007/s10584-012-0420-x Authors S. Dahech, Faculty of Arts and Humanities, SYFACTE Laboratory, University of Sfax, Sfax, Tunisia G. Beltrando, UMR PRODIG of CNRS, University of Paris VII (Denis Diderot), Paris, France Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    There is a growing scholarship on the role of the amateur, and amateur societies, in the production and circulation of weather and climate knowledge in the past. Yet relatively little attention has been paid to the actual and potential contribution of contemporary amateur meteorologists in this respect. In this paper we first examine the importance of the amateur historically in the production of local weather knowledge and also in the emergence of professional meteorology. Drawing on semi-structured interviews with members of one contemporary UK based amateur meteorological organisation—the Climatological Observers Link (COL)—we then investigate the nature and extent of contemporary amateur meteorologists’ contributions to a wide range of different ‘publics’ today, which include both popular and professional communities. Finally, we interrogate our interview data to identify whether COL members themselves recognise a wider role for their expertise at a time of increasing popular and scientific interest in weather and climate and in an era when the inclusion of non-certified experts in policy decision making processes is being advocated. Content Type Journal Article Pages 1-21 DOI 10.1007/s10584-012-0415-7 Authors Georgina H. Endfield, School of Geography, University of Nottingham, Nottingham, NG7 2RD England, UK Carol Morris, School of Geography, University of Nottingham, Nottingham, NG7 2RD England, UK Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Using daily precipitable water ( PW ) and 850 hPa monsoon wind, which represent large-scale moisture and dynamic conditions for monsoon development, we analyze potential changes in Asian monsoon onset, retreat and duration simulated by 13 IPCC AR4 models. Most models are able to reproduce the observed temporal and spatial evolution patterns of the Asian monsoon system. Nevertheless, there are significant model biases and some models fail in reproducing the broad structure. Under a warmed climate, changes in onset and duration days are only moderate (about 3–10 days), with significant discrepancies among the models, particularly over the East Asia land area where the models are almost equally divided. In the tropical Indian Ocean, maritime continent and Indochina Peninsula, the majority of the models tend to simulate delayed onset and shortened duration while in the western North Pacific most models exhibit an early onset and longer duration. There are two reasons leading to such uncertainties: (1) the key processes determining the Asian monsoon onset/retreat are different among the models. Some are more influenced by ENSO-like processes. But in some models, monsoon onset/retreat is more significantly correlated to circulations in the tropics. (2) The model-simulated changes in these dominant processes are different. In some models, surface warming is more intense in the central and eastern Pacific Ocean with El Niño-like patterns, while others do not show such features. If the model-simulated monsoon onset/retreat is correlated to the central and eastern Pacific warming and at the same time the model simulates much larger warming of the central and eastern Pacific Ocean, then it is very likely that these models will show significant delay of south Asian monsoon onset and shortened duration. In some models, the delayed onsets are more related to the reduction of westerlies in the west of the warm pool region. The patterns of anomalous SST and wind conditions identified in this study are consistent with each other and both are likely linked to the weakening and westward shift of Walker circulation in the warm pool and maritime continent region. Increases in precipitable water associated with global warming do not change monsoon rainfall and circulation seasonality much but they can result in increased rainfall intensity once the summer monsoon is established. Content Type Journal Article Pages 1-22 DOI 10.1007/s00382-012-1289-0 Authors Huqiang Zhang, Centre for Australian Weather and Climate Research, A Partnership between the Australian Bureau of Meteorology and CSIRO, GPO Box 1289k, Melbourne, VIC 3001, Australia Ping Liang, Shanghai Regional Climate Center, China Meteorological Administration, Shanghai, China A. Moise, Centre for Australian Weather and Climate Research, A Partnership between the Australian Bureau of Meteorology and CSIRO, GPO Box 1289k, Melbourne, VIC 3001, Australia L. Hanson, Centre for Australian Weather and Climate Research, A Partnership between the Australian Bureau of Meteorology and CSIRO, GPO Box 1289k, Melbourne, VIC 3001, Australia Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Temperature variation is studied at different altitudes and orientation on the island of Tenerife, according to the trends in the mean, maximum and minimum at 21 meteorological stations. Reference series are obtained by sectors, along with a representative overall series for Tenerife, in which temperature shows a statistically significant growth trend of 0.09 ± 0.04°C/decade since 1944. Night-time temperatures have risen most (0.17°C ± 0.04°C/decade), while by day they have been more stable. Consequently, the diurnal temperature range between day and night has narrowed. By regions, warming has been much more intense in the high mountains than the other sectors below the inversion layer between 600 and 1,400 m altitude, and progressively milder towards the coast. The temperature rise on the windward (north-northeast) slopes is greater than on the leeward side and could be related to the increase in cloudiness on the northern side. The general warming of the island is less than in continental areas at between 24 and 44ºN, being closer to the sea surface temperature in the same area. This is probably explained largely by the insular conditions. In fact warming is more evident in the high mountains (0.14 ± 0.07°C/decade), where the tempering effect of the ocean and the impact of changes in the stratocumulus is weaker, being similar to the mean continental values in the northern hemisphere. Content Type Journal Article Pages 1-13 DOI 10.1007/s10584-012-0407-7 Authors José L. Martín, Canary Islands Agency for Climate Change and Sustainable Development, Observatory of Sustainable Development, C/. Zarate y Penichet, 5, 38071 Santa Cruz de Tenerife, Spain José Bethencourt, Canary Islands Agency for Climate Change and Sustainable Development, 38071 Santa Cruz de Tenerife, Spain Emilio Cuevas-Agulló, Izaña Atmospheric Research Centre (AEMET), 38071 SC de Tenerife, Spain Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description: Cultural spaces of climate Content Type Journal Article Pages 1-4 DOI 10.1007/s10584-012-0416-6 Authors Georgina Endfield, School of Geography, University of Nottingham, University Park, Nottingham, NG7 2RD England, UK Carol Morris, School of Geography, University of Nottingham, University Park, Nottingham, NG7 2RD England, UK Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Brightness temperature observations from Microwave Sounding Unit and Advanced Microwave Sounding Unit-A (AMSU-A) on board National Oceanic and Atmospheric Administration (NOAA) satellites have been widely utilized for estimating the global climate trend in the troposphere and stratosphere. A common approach for deriving the trend is linear regression, which implicitly assumes the trend being a straight line over the whole length of a time series and is often highly sensitive to the data record length. This study explores a new adaptive and temporally local data analysis method—Ensemble Empirical Mode Decomposition (EEMD)—for estimating the global trends. In EEMD, a non-stationary time series is decomposed adaptively and locally into a sequence of amplitude-frequency modulated oscillatory components and a time-varying trend. The AMSU-A data from the NOAA-15 satellite over the time period from October 26, 1998 to August 7, 2010 are employed for this study. Using data over Amazon rainforest areas, it is shown that channel 3 is least sensitive to the orbital drift among four AMSU-A surface sensitive channels. The decadal trends of AMSU-A channel 3 and other eight channels in the troposphere and stratosphere are deduced and compared using both methods. It is shown that the decadal climate trends of most AMSU-A channels are nonlinear except for channels 3–4 in Northern Hemisphere only and channels 12–13. Although the decadal trend variation of the global average brightness temperature is no more than 0.2 K, the regional decadal trend variation could be more (less) than 3 K (−3 K) in high latitudes and over high terrains. Content Type Journal Article Pages 1-17 DOI 10.1007/s00382-012-1296-1 Authors Z. Qin, Center of Data Assimilation for Research and Application, Nanjing University of Information Science and Technology, Nanjing, China X. Zou, Center of Data Assimilation for Research and Application, Nanjing University of Information Science and Technology, Nanjing, China F. Weng, Center for Satellite Applications and Research, NOAA/NESDIS, Camp Springs, MD 20746, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Climate models often use a simplified and static representation of vegetation characteristics to determine fluxes of energy, momentum and water vapour between surface and lower atmosphere. In order to analyse the impact of short term variability in vegetation phenology, we use remotely-sensed leaf area index and albedo products to examine the role of vegetation in the coupled land–atmosphere system. Perfect model experiments are carried out to determine the impact of realistic temporal variability of vegetation on potential predictability of evaporation and temperature, as well as model skill of EC-Earth simulations. The length of the simulation period is hereby limited by the availability of satellite products to 2000–2010. While a realistic representation of vegetation positively influences the simulation of evaporation and its potential predictability, a positive impact on 2 m temperature is of smaller magnitude, regionally confined and more pronounced in climatically extreme years. Content Type Journal Article Pages 2733-2746 DOI 10.1007/s00382-012-1572-0 Authors Martina Weiss, Royal Netherlands Meteorological Institute (KNMI), De Bilt, The Netherlands Bart van den Hurk, Royal Netherlands Meteorological Institute (KNMI), De Bilt, The Netherlands Reindert Haarsma, Royal Netherlands Meteorological Institute (KNMI), De Bilt, The Netherlands Wilco Hazeleger, Royal Netherlands Meteorological Institute (KNMI), De Bilt, The Netherlands Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575 Journal Volume Volume 39 Journal Issue Volume 39, Number 11

Description:    This study investigates future changes of Global Monsoon (GM) under anthropogenic global warming using 20 coupled models that participated in the phase five of Coupled Model Intercomparison Project (CMIP5) by comparing two runs: the historical run for 1850–2005 and the Representative Concentration Pathway (RCP) 4.5 run for 2006–2100. A metrics for evaluation of models’ performance on GM is designed to document performance for 1980–2005 and best four models are selected. The four best models’ multi-model ensemble (B4MME) projects the following changes in the twenty-first century under the RCP4.5 scenario. (1) Monsoon domain will not change appreciably but land monsoon domain over Asia tends to expand westward by 10.6 %. (2) The annual mean and range of GM precipitation and the percentage of local summer rainfall will all amplify at a significant level over most of the global region, both over land and over ocean. (3) There will be a more prominent northern-southern hemispheric asymmetry and eastern-western hemispheric asymmetry. (4) Northern Hemisphere (NH) monsoon onset will be advanced and withdrawal will be delayed. (5) Changes in monsoon precipitation exhibits huge differences between the NH and the Southern hemisphere (SH). The NH monsoon precipitation will increase significantly due to increase in temperature difference between the NH and SH, significant enhancement of the Hadley circulation, and atmospheric moistening, against stabilization of troposphere. There is a slight decrease of the Walker circulation but not significant against the inter-model spread. There are important differences between the CMIP 3 and CMIP5 results which are discussed in detail. Content Type Journal Article Pages 1-19 DOI 10.1007/s00382-012-1564-0 Authors June-Yi Lee, Department of Meteorology and International Pacific Research Center, University of Hawaii/IPRC, POST Bldg, Room 409E, 1680 East-West Road, Honolulu, HI 96822, USA Bin Wang, Department of Meteorology and International Pacific Research Center, University of Hawaii/IPRC, POST Bldg, Room 409E, 1680 East-West Road, Honolulu, HI 96822, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    This paper is dedicated to the analysis of winter cold spells over Western Europe in the simulations of the 5th phase of the Coupled Model Intercomparison Project (CMIP5). Both model biases and responses in a warming climate are discussed using historical simulations and the 8.5 W/m 2 Representative Concentration Pathway (RCP8.5) scenario, respectively on the 1979–2008 and 2070–2099 periods. A percentile-based index (10th percentile of daily minimum temperature, Q10) with duration and spatial extent criteria is used to define cold spells. Related diagnostics (intensity, duration, extent, and severity as a combination of the former three statistics) of 13 models are compared to observations and suggest that models biases on severity are mainly due to the intensity parameter rather than to duration and extent. Some hypotheses are proposed to explain these biases, that involve large-scale dynamics and/or radiative fluxes related to clouds. Evolution of cold spells characteristics by the end of the century is then discussed by comparing RCP8.5 and historical simulations. In line with the projected rise of mean temperature, “present-climate” cold spells (computed with the 1979–2008 10th percentile, Q10P) are projected to be much less frequent and, except in one model, less severe. When cold spells are defined from the future 10th percentile threshold (“future-climate” cold spells, Q10F), all models simulate a decrease of their intensity linearly related to the seasonal mean warming. Some insights are given to explain the inter-model diversity in the magnitude of the cold spells response. In particular, the snow-albedo feedback is suggested to play an important role, while for some models changes in large-scale dynamics are also not negligible. Content Type Journal Article Pages 1-13 DOI 10.1007/s00382-012-1565-z Authors Y. Peings, CNRM-GAME, Météo-France and CNRS, Toulouse, France J. Cattiaux, CNRM-GAME, Météo-France and CNRS, Toulouse, France H. Douville, CNRM-GAME, Météo-France and CNRS, Toulouse, France Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Expert elicitation studies have become important barometers of scientific knowledge about future climate change (Morgan and Keith, Environ Sci Technol 29(10), 1995 ; Reilly et al., Science 293(5529):430–433, 2001 ; Morgan et al., Climate Change 75(1–2):195–214, 2006 ; Zickfeld et al., Climatic Change 82(3–4):235–265, 2007 , Proc Natl Acad Sci 2010 ; Kriegler et al., Proc Natl Acad Sci 106(13):5041–5046, 2009 ). Elicitations incorporate experts’ understanding of known flaws in climate models, thus potentially providing a more comprehensive picture of uncertainty than model-driven methods. The goal of standard elicitation procedures is to determine experts’ subjective probabilities for the values of key climate variables. These methods assume that experts’ knowledge can be captured by subjective probabilities—however, foundational work in decision theory has demonstrated this need not be the case when their information is ambiguous (Ellsberg, Q J Econ 75(4):643–669, 1961 ). We show that existing elicitation studies may qualitatively understate the extent of experts’ uncertainty about climate change. We designed a choice experiment that allows us to empirically determine whether experts’ knowledge about climate sensitivity (the equilibrium surface warming that results from a doubling of atmospheric CO 2 concentration) can be captured by subjective probabilities. Our results show that, even for this much studied and well understood quantity, a non-negligible proportion of climate scientists violate the choice axioms that must be satisfied for subjective probabilities to adequately describe their beliefs. Moreover, the cause of their violation of the axioms is the ambiguity in their knowledge. We expect these results to hold to a greater extent for less understood climate variables, calling into question the veracity of previous elicitations for these quantities. Our experimental design provides an instrument for detecting ambiguity, a valuable new source of information when linking climate science and climate policy which can help policy makers select decision tools appropriate to our true state of knowledge. Content Type Journal Article Category Letter Pages 1-10 DOI 10.1007/s10584-012-0620-4 Authors Antony Millner, Department of Agricultural and Resource Economics, University of California, Berkeley, CA, USA Raphael Calel, Grantham Research Institute on Climate Change and the Environment, London School of Economics and Political Science, London, UK David A. Stainforth, Grantham Research Institute on Climate Change and the Environment, London School of Economics and Political Science, London, UK George MacKerron, Grantham Research Institute on Climate Change and the Environment, London School of Economics and Political Science, London, UK Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    We examined if climate change in two dry ecosystems—Mediterranean (DME) and Semiarid (SAE)—would cause substantial reduction in the production of annual vegetation. Field measurements and computer simulations were used to examine the following six climate change scenarios: (1) rainfall amount reduction; (2) increases of 10 % in annual evaporation rate and 5 % in annual temperature; (3) increase in magnitude of rainfall events, accompanied by reductions in frequency and seasonal variation; (4) postponement of the beginning of the first rainfall event of the growing season; (5) long dry spells during the growing season; and (6) early ending of the growing season. The results revealed the following outcomes. a) Reduction by 5–35 % in annual rainfall amount did not significantly affect productivity in the DME, but a large (25–35 %) decrease in rainfall would change vegetation productivity in the SAE and lead to a patchier environment. b) Similar results were observed: when temperature and evaporation rate were increased; when the magnitude of rainfall events increased but their frequency decreased; and during a long mid-season dry spell. c) In both ecosystems, changes in the temporal distribution of rainfall, especially at the beginning of the season, caused the largest reduction in productivity, accompanied by increased patchiness. d) Long-term data gathered during the last three decades indicated that both environments exhibited high resilience of productivity under rainfall variability. These results imply that the response of dry ecosystems to climate change is not characterized by a dramatic decrease in productivity. Moreover, these ecosystems are more resilient than expected, and their herbaceous productivity might undergo drastic changes only under more severe scenarios than those currently predicted in the literature. Content Type Journal Article Pages 1-17 DOI 10.1007/s10584-012-0614-2 Authors Rakefet Shafran-Nathan, Department of Geography and Environmental Development, Ben-Gurion University of the Negev, Beer-Sheva, 84105 Israel Tal Svoray, Department of Geography and Environmental Development, Ben-Gurion University of the Negev, Beer-Sheva, 84105 Israel Avi Perevolotsky, Department of Agronomy and Natural Resources, The Volcani Center, P.O. Box 6, Bet Dagan, 50250 Israel Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description: Erratum to: Simulating cold season snowpack: Impacts of snow albedo and multi-layer snow physics Content Type Journal Article Category Erratum Pages 1-1 DOI 10.1007/s10584-012-0621-3 Authors D. Waliser, JPL/CALTECH, Pasadena, CA, USA J. Kim, UCLA, Los Angeles, CA, USA Y. Xue, UCLA, Los Angeles, CA, USA Y. Chao, JPL/CALTECH, Pasadena, CA, USA A. Eldering, JPL/CALTECH, Pasadena, CA, USA R. Fovell, UCLA, Los Angeles, CA, USA A. Hall, UCLA, Los Angeles, CA, USA Q. Li, UCLA, Los Angeles, CA, USA K. N. Liou, UCLA, Los Angeles, CA, USA J. McWilliams, UCLA, Los Angeles, CA, USA S. Kapnick, UCLA, Los Angeles, CA, USA R. Vasic, UCLA, Los Angeles, CA, USA F. De Sales, UCLA, Los Angeles, CA, USA Y. Yu, UCLA, Los Angeles, CA, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Future scenarios of the energy system under greenhouse gas emission constraints depict dramatic growth in a range of energy technologies. Technological growth dynamics observed historically provide a useful comparator for these future trajectories. We find that historical time series data reveal a consistent relationship between how much a technology’s cumulative installed capacity grows, and how long this growth takes. This relationship between extent (how much) and duration (for how long) is consistent across both energy supply and end-use technologies, and both established and emerging technologies. We then develop and test an approach for using this historical relationship to assess technological trajectories in future scenarios. Our approach for “learning from the past” contributes to the assessment and verification of integrated assessment and energy-economic models used to generate quantitative scenarios. Using data on power generation technologies from two such models, we also find a consistent extent - duration relationship across both technologies and scenarios. This relationship describes future low carbon technological growth in the power sector which appears to be conservative relative to what has been evidenced historically. Specifically, future extents of capacity growth are comparatively low given the lengthy time duration of that growth. We treat this finding with caution due to the low number of data points. Yet it remains counter-intuitive given the extremely rapid growth rates of certain low carbon technologies under stringent emission constraints. We explore possible reasons for the apparent scenario conservatism, and find parametric or structural conservatism in the underlying models to be one possible explanation. Content Type Journal Article Pages 1-15 DOI 10.1007/s10584-012-0618-y Authors C. Wilson, Tyndall Centre for Climate Change Research, University of East Anglia, Norwich, UK A. Grubler, International Institute for Applied Systems Analysis, Laxenburg, Austria N. Bauer, Potsdam Institute for Climate Impact Research, Potsdam, Germany V. Krey, International Institute for Applied Systems Analysis, Laxenburg, Austria K. Riahi, International Institute for Applied Systems Analysis, Laxenburg, Austria Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Global warming has become a controversial public policy issue in spite of broad scientific consensus that it is real and that human activity is a contributing factor. It is likely that public consensus is also needed to support policies that might counteract it. It is therefore important to understand how people form and update their beliefs about climate change. Using unique survey data on beliefs about the occurrence of the effects of global warming, I estimate how local temperature fluctuations influence what individuals believe about these effects. I find that some features of the updating process are consistent with rational updating. I also test explicitly for the presence of several heuristics known to affect belief formation and find strong evidence for representativeness, some evidence for availability, and no evidence for spreading activation. I find that very short-run temperature fluctuations (1 day–2 weeks) have no effect on beliefs about the occurrence of global warming, but that longer-run fluctuations (1 month–1 year) are significant predictors of beliefs. Only respondents with a conservative political ideology are affected by temperature abnormalities. Content Type Journal Article Pages 1-20 DOI 10.1007/s10584-012-0615-1 Authors Tatyana Deryugina, University of Illinois at Urbana-Champaign, Champaign, IL, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    In the present paper the effect of an abrupt change of the atmospheric radiative forcing is investigated by means of a global climate model that includes a mixed layer ocean. In assessing if, under such a change, the model response has a bifurcation point, the steady solution is studied for a sudden decrease of CO 2 concentration from its actual value. It is found that there is a critical threshold for CO 2 content below which the model ends up to a snowball Earth. It occurs for a few percentage changes of CO 2 concentration around the threshold because the model strongly depends on the relationship among atmospheric temperature, water vapor content and the sudden ice-albedo feedback activation, even in the subtropical regions. Moreover, results suggest that the transition to ice-covered Earth is clearly favoured when Q-flux corrections (i.e. the parameterization of ocean heat transports) are removed. Content Type Journal Article Pages 1-12 DOI 10.1007/s00382-012-1581-z Authors Isabella Bordi, Department of Physics, Sapienza University of Rome, Rome, Italy Klaus Fraedrich, Universität Hamburg, KlimaCampus, Hamburg, Germany Alfonso Sutera, Department of Physics, Sapienza University of Rome, Rome, Italy Xiuhua Zhu, Universität Hamburg, KlimaCampus, Hamburg, Germany Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Regional climate projections in the Pacific region are potentially sensitive to a range of existing model biases. This study examines the implications of coupled model biases on regional climate projections in the tropical western Pacific. Model biases appear in the simulation of the El Niño Southern Oscillation, the location and movement of the South Pacific Convergence Zone, rainfall patterns, and the mean state of the ocean–atmosphere system including the cold tongue bias and erroneous location of the edge of the Western Pacific warm pool. These biases are examined in the CMIP3 20th century climate models and used to provide some context to the uncertainty in interpretations of regional-scale climate projections for the 21st century. To demonstrate, we provide examples for two island nations that are located in different climate zones and so are affected by different biases: Nauru and Palau. We discuss some of the common approaches to analyze climate projections and whether they are effective in reducing the effect of model biases. These approaches include model selection, calculating multi model means, downscaling and bias correcting. Content Type Journal Article Pages 1-15 DOI 10.1007/s10584-012-0603-5 Authors Jaclyn N. Brown, Centre for Australian Weather and Climate Research, CSIRO, Hobart, Australia Alex Sen Gupta, Climate Change Research Centre & ARC Centre of Excellence for Climate System Science, The University of New South Wales, Sydney, Australia Josephine R. Brown, Centre for Australian Weather and Climate Research, Bureau of Meteorology, Melbourne, Australia Les C. Muir, Department of Geology and Geophysics, Yale University, New Haven, USA James S. Risbey, Centre for Australian Weather and Climate Research, CSIRO, Hobart, Australia Penny Whetton, Centre for Australian Weather and Climate Research, CSIRO, Hobart, Australia Xuebin Zhang, Centre for Australian Weather and Climate Research, CSIRO, Hobart, Australia Alexandre Ganachaud, Institut de Recherche pour le Développement (IRD), UMR5566, LEGOS, BP A5, Nouméa, New Caledonia Brad Murphy, Centre for Australian Weather and Climate Research, Bureau of Meteorology, Melbourne, Australia Susan E. Wijffels, Centre for Australian Weather and Climate Research, CSIRO, Hobart, Australia Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    A hindcast experiment of the Mediterranean present-day climate is performed using a fully-coupled Atmosphere–Ocean Regional Climate Model (AORCM) for the Mediterranean basin. The new model, called LMDz-NEMO-Med, is composed of LMDz4-regional as atmospheric component and of NEMOMED8 as oceanic component. This AORCM equilibrates freely, without any flux adjustment, neither in fresh water nor in heat. At its atmospheric lateral boundary conditions, it is driven by ERA-40 data from 1958 to 2001, after a spin-up of 40 years in coupled configuration. The model performance is assessed and compared with available observational datasets. The model skill in reproducing mean state and inter-annual variability of main atmospheric and oceanic surface fields is in line with that of state-of-the-art AORCMs. Considering the ocean behaviour, the inter-annual variations of the basin-scale heat content are in very good agreement with the observations. The model results concerning salt content could not be adequately validated. High inter-annual variability of deep convection in the Gulf of Lion is simulated, with 53 % of convective winters, representative of the present climate state. The role of different factors influencing the deep convection and its inter-annual variability is examined, including dynamic and hydrostatic ocean preconditioning and atmospheric surface forcing. A conceptual framework is outlined and validated in linking the occurrence of deep convection to the efficiency of the integrated surface buoyancy fluxes along the winter season to mix the initially stratified averaged water column down to the convective threshold depth. This simple framework (based only on 2 independent variables) is able to explain 60 % (resp. 69 %) of inter-annual variability of the deep water formation rate (resp. maximum mixed layer depth) for the West Mediterranean Deep Water (WMDW) formation process. Content Type Journal Article Pages 1-24 DOI 10.1007/s00382-012-1527-5 Authors Blandine L’Hévéder, Laboratoire de Météorologie Dynamique, Université Paris VI, Tour 45-55, 3e étage, Case postale 99, 4, place Jussieu, 75252 Paris Cedex 05, France Laurent Li, Laboratoire de Météorologie Dynamique, Université Paris VI, Tour 45-55, 3e étage, Case postale 99, 4, place Jussieu, 75252 Paris Cedex 05, France Florence Sevault, Centre National de Recherches Météorologiques, Météo-France, Toulouse, France Samuel Somot, Centre National de Recherches Météorologiques, Météo-France, Toulouse, France Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    A set of global climate model simulations for the last thousand years developed by the Max Planck Institute is compared with paleoclimate proxy data and instrumental data, focusing on surface temperatures for land areas between 30° and 75°N. The proxy data are obtained from six previously published Northern Hemispheric-scale temperature reconstructions, here re-calibrated for consistency, which are compared with the simulations utilizing a newly developed statistical framework for ranking several competing simulations by means of their statistical distance against past climate variations. The climate model simulations are driven by either “low” or “high” solar forcing amplitudes (0.1 and 0.25 % smaller total solar irradiance in the Maunder Minimum period compared to the present) in addition to several other known climate forcings of importance. Our results indicate that the high solar forcing amplitude results in a poorer match with the hemispheric-scale temperature reconstructions and lends stronger statistical support for the low-amplitude solar forcing. However, results are likely conditional upon the sensitivity of the climate model used and strongly dependent on the choice of temperature reconstruction, hence a greater consensus is needed regarding the reconstruction of past temperatures as this currently provides a great source of uncertainty. Content Type Journal Article Pages 1-11 DOI 10.1007/s00382-012-1526-6 Authors Alistair Hind, Department of Physical Geography and Quaternary Geology, Bert Bolin Centre for Climate Research, Stockholm University, 106 91 Stockholm, Sweden Anders Moberg, Department of Physical Geography and Quaternary Geology, Bert Bolin Centre for Climate Research, Stockholm University, 106 91 Stockholm, Sweden Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The Upper Brahmaputra River Basin is prone to natural disasters and environmental stresses (floods, droughts and bank erosion, delayed rainfall, among others) creating an environment of uncertainty and setting the basin back in terms of socio-economic development. The climate change literature shows that agriculture and ecosystems and their services are highly climate sensitive, yet they are the main sources of livelihood that supports a large proportion of residents of the tributaries of the Brahmaputra River Basin. The continuous depletion of ecosystems and loss of agricultural outputs resulting from environmental stressors has a substantial impact on the socio-economic wellbeing of the basins residents, particularly the vulnerable rural poor. This paper uses spatially explicit data from Census, Household Surveys and Earth Observation to develop a transferable methodological approach which investigates the extent of dependence on agriculture and ecosystems as a source of livelihood in the contrasting sub-basins of the Brahmaputra River in the State of Assam, India and Bhutan, and the risk to these livelihood dependencies in these sub-basins due to potential environmental impacts of climate change. The results from this study constitute a case study in the development of a systematic and spatially explicit set of tools that inform and assist policy makers in the appropriate interventions to secure the livelihood benefits of sustainably managed agriculture in the face of environmental change. Content Type Journal Article Pages 1-15 DOI 10.1007/s10584-012-0573-7 Authors Fiifi Amoako Johnson, Faculty of Human and Social Sciences, University of Southampton, Southampton, Hampshire, UK Craig William Hutton, Faculty of Human and Social Sciences, University of Southampton, Southampton, Hampshire, UK Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    The contributions of several IPY health projects are highlighted in the context of population health indicators for Inuit Nunangat. Food and housing are two critical social determinants of health contributing to health issues on many levels. The nutritional deficit associated with food insecurity and the transition away from traditional and towards market foods represents a dual risk with profound consequences. Knowledge of the physiological benefits associated with traditional food consumption is increasing, including for mental health and chronic disease. Ensuring the safety of traditional foods in terms of zoonotic diseases is thus highly valuable and efforts to institute adequate monitoring and address knowledge gaps are underway. Acute respiratory disease among the young remains a significant public health issue with potential long term effects. The human papilloma virus is manifesting itself among women across northern Canada with high risk types that are more similar to profiles observed in Europe than in North America with possible implications for immunization programs. Despite a high prevalence of Hepatitis B virus infections among residents of Inuit Nunangat, the outcomes appear to be relatively benign. Communication of new knowledge on the manifestation of this virus among northern populations is provided to health care providers in the North through modern technology. Content Type Journal Article Pages 1-23 DOI 10.1007/s10584-012-0569-3 Authors Sandra Owens, Axe santé des populations et environnementale, Centre de recherche du Centre hospitalier universitaire de Québec, Quebec, Canada Philippe De Wals, Département de médecine sociale et préventive, Université Laval, Quebec, Canada Grace Egeland, Centre for Indigenous Peoples’ Nutrition and Environment (CINE) and School of Dietetics and Human Nutrition, Macdonald Campus, McGill University, Montreal, Canada Christopher Furgal, Departments of Indigenous Studies and Environment and Resource Studies/Science, Gzowski College Trent University, Peterborough, Canada Yang Mao, Centre for Chronic Disease Prevention and Control, Public Health Agency of Canada, Ottawa, Canada Gerald Y. Minuk, Department of Internal Medicine, University of Manitoba, Winnipeg, Canada Paul A. Peters, Health Analysis Division, Statistics Canada, Ottawa, Canada Manon Simard, Nunavik Research Center, Makivik Corporation, Nunavik, Canada Éric Dewailly, Axe santé des populations et environnementale, Centre de recherche du Centre hospitalier universitaire de Québec, Quebec, Canada Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    The nocturnal precipitation in the Sichuan Basin in summer has been studied in many previous works. This paper expands the study on the diurnal cycle of precipitation in the Sichuan Basin to the whole year. Results show that the nocturnal precipitation has a specific quasi-stationary feature in the basin. It occurs not only in summer but also in other three seasons, even more remarkable in spring and autumn than in summer. There is a prominent eastward timing delay in the nocturnal precipitation, that is, the diurnal peak of precipitation occurs at early-night in the western basin whereas at late-night in the center and east of the basin. The Tibetan Plateau plays an essential role in the formation of this quasi-stationary nocturnal precipitation. The early-night peak of precipitation in the western basin is largely due to strong ascending over the plateau and its eastern lee side. In the central and eastern basin, three coexisting factors contribute to the late-night peak of precipitation. One is the lower-tropospheric southwesterly flow around the southeastern edge of the Tibetan Plateau, which creates a strong cyclonic rotation and ascendance in the basin at late-night, as well as brings abundant water vapor. The second is the descending motion downslope along the eastern lee side of the plateau, together with an air mass accumulation caused by the warmer air mass transport from the southeast of the Yunnan-Guizhou Plateau, creating a diabatic warming at low level of the troposphere in the central basin. The third is a cold advection from the plateau to the basin at late-night, which leads to a cooling in the middle troposphere over the central basin. All these factors are responsible for precipitation to occur at late-night in the central to eastern basin. Content Type Journal Article Pages 1-18 DOI 10.1007/s00382-012-1521-y Authors Xia Jin, Chinese Academy of Meteorological Sciences, China Meteorological Administration, Beijing, China Tongwen Wu, National Climate Center, China Meteorological Administration, 46 Zhongguancun Nandajie, Beijing, 100081 People’s Republic of China Laurent Li, Laboratoire de Météorologie Dynamique, IPSL, CNRS/UPMC, Paris, France Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The summer circulation over the eastern Mediterranean and the Middle East (EMME) is dominated by persistent northerly winds (Etesians) whose ventilating effect counteracts the adiabatic warming induced by large scale subsidence. The ERA40 dataset is used to study the vertical distribution of these circulation features, which both appear to be reconciled manifestations of the South Asian monsoon influence. As predicted by past idealized modeling studies, in late spring a westward expanding upper level warm structure and subsidence areas are associated with Rossby waves excited by the monsoon convection. Steep sloping isentropes that develop over the EMME facilitate further subsidence on the western and northern periphery of the warm structure, which is exposed to the midlatitude westerlies. The northerly flow and descent over the eastern Mediterranean have maxima in July that are strikingly synchronous to the monsoon convection over northern India, where the weaker easterly jet favors a stronger Rossby wave response and consequent impact on the EMME circulation. The pronounced EMME topography modifies the monsoon induced structure, firstly, by inducing orographically locked summer anticyclones. These enhance the mid and low level northwesterly flow at their eastern flanks, leading to distinct subsidence maxima over the eastern Mediterranean and Iran. Secondly, topography amplifies the subsidence and the northerly flow over the Aegean, Red Sea, the Iraq—Gulf region and to the east of the Caspian Sea. Content Type Journal Article Pages 1-21 DOI 10.1007/s00382-012-1528-4 Authors Evangelos Tyrlis, Energy, Environment and Water Research Center, The Cyprus Institute, 20 Konstantinou Kavafi Street, 2121 Nicosia, Cyprus Jos Lelieveld, Energy, Environment and Water Research Center, The Cyprus Institute, 20 Konstantinou Kavafi Street, 2121 Nicosia, Cyprus Benedikt Steil, Max Planck Institute for Chemistry, 55020 Mainz, Germany Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Northeast China (NEC) is one of the major agricultural production areas in China and also an obvious region of climate warming. We were motivated to investigate the impacts of climate warming on the northern limits of maize planting. Additionally, we wanted to assess how spatial shifts in the cropping system impact the maize yields in NEC. To understand these impacts, we used the daily average air temperature data in 72 weather stations and regional experiment yield data from Jilin Province. Averaged across NEC, the annual air temperature increased by 0.38 °C per decade. The annual accumulated temperature above 10 °C (AAT10) followed a similar trend, increased 66 °C d per decade from 1961 to 2007, which caused a northward expansion of the northern limits of maize. The warming enabled early-maturing maize hybrids to be sown in the northern areas of Heilongjiang Province where it was not suitable for growing maize before the warming. In the southern areas of Heilongjiang Province and the eastern areas of Jilin Province, the early-maturing maize hybrids could be replaced by the middle-maturing hybrids with a longer growing season. The maize in the northern areas of Liaoning Province was expected to change from middle-maturing to late-maturing hybrids. Changing the hybrids led to increase the maize yield. When the early-maturing hybrids were replaced by middle-maturing hybrids in Jilin Province, the maize yields would increase by 9.8 %. Similarly, maize yields would increase by 7.1 % when the middle-maturing hybrids were replaced by late-maturing hybrids. Content Type Journal Article Pages 1-12 DOI 10.1007/s10584-012-0594-2 Authors Zhijuan Liu, College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan West Rd, Haidian District, Beijing 100193, China Xiaoguang Yang, College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan West Rd, Haidian District, Beijing 100193, China Fu Chen, College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan West Rd, Haidian District, Beijing 100193, China Enli Wang, CSIRO Land and Water, GPO Box 1666, Black Mountain, Canberra, ACT 2601 Australia Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Residuals from agricultural pesticides threaten the environment and human health. Climate change alters these externalities because it affects pest pressure and pesticide application rates. This study examines damages from pesticide externalities in US agriculture under different climate projections and the effects of alternative regulations. We find divergent impacts of externality regulation and climate change on agricultural production in the US. A Pigovian tax on pesticide externalities generally increases crop production cost, but farm revenue improves because of increased commodity prices. Climate change generally decreases US farm revenue because production increases and prices fall. Results also show a heterogeneous effect of climate change on pest management intensities across major crops. Content Type Journal Article Pages 1-13 DOI 10.1007/s10584-012-0585-3 Authors Nikolinka G. Shakhramanyan, Research unit Sustainability and Global Change, Hamburg University and Centre for Marine and Atmospheric Science, Grindelberg 5, 20144 Hamburg, Germany Uwe A. Schneider, Research unit Sustainability and Global Change, Hamburg University and Centre for Marine and Atmospheric Science, Grindelberg 5, 20144 Hamburg, Germany Bruce A. McCarl, Department of Agricultural Economics, Texas A&M University, College Station, TX 77843-2124, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    A general increase in precipitation has been observed in Germany in the last century, and potential changes in flood generation and intensity are now at the focus of interest. The aim of the paper is twofold: a) to project the future flood conditions in Germany accounting for various river regimes (from pluvial to nival-pluvial regimes) and under different climate scenarios (the high, A2, low, B1, and medium, A1B, emission scenarios) and b) to investigate sources of uncertainty generated by climate input data and regional climate models. Data of two dynamical Regional Climate Models (RCMs), REMO (REgional Model) and CCLM (Cosmo-Climate Local Model), and one statistical-empirical RCM, Wettreg (Wetterlagenbasierte Regionalisierungsmethode: weather-type based regionalization method), were applied to drive the eco-hydrological model SWIM (Soil and Water Integrated Model), which was previously validated for 15 gauges in Germany. At most of the gauges, the 95 and 99 percentiles of the simulated discharge using SWIM with observed climate data had a good agreement with the observed discharge for 1961–2000 (deviation within ±10 %). However, the simulated discharge had a bias when using RCM climate as input for the same period. Generalized Extreme Value (GEV) distributions were fitted to the annual maximum series of river runoff for each realization for the control and scenario periods, and the changes in flood generation over the whole simulation time were analyzed. The 50-year flood values estimated for two scenario periods (2021–2060, 2061–2100) were compared to the ones derived from the control period using the same climate models. The results driven by the statistical-empirical model show a declining trend in the flood level for most rivers, and under all climate scenarios. The simulations driven by dynamical models give various change directions depending on region, scenario and time period. The uncertainty in estimating high flows and, in particular, extreme floods remains high, due to differences in regional climate models, emission scenarios and multi-realizations generated by RCMs. Content Type Journal Article Pages 1-33 DOI 10.1007/s10584-012-0586-2 Authors Shaochun Huang, Potsdam Institute for Climate Impact Research, P.O. Box 601203, Telegrafenberg, 14412 Potsdam, Germany Fred F. Hattermann, Potsdam Institute for Climate Impact Research, P.O. Box 601203, Telegrafenberg, 14412 Potsdam, Germany Valentina Krysanova, Potsdam Institute for Climate Impact Research, P.O. Box 601203, Telegrafenberg, 14412 Potsdam, Germany Axel Bronstert, Potsdam Institute for Climate Impact Research, P.O. Box 601203, Telegrafenberg, 14412 Potsdam, Germany Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Observations indicate a surface cooling trend during the East Asian summer in recent decades, against a background of global warming. This cooling trend is re-examined using station data from 1951 to 2007, and atmospheric general circulation model (AGCM) simulations are performed to investigate the possible influence of changes in external forcing. The numerical experiments are designed to investigate the effects of four types of external forcing: greenhouse gases (GHGs), Total Solar Irradiance (TSI), ozone, and the direct effects of aerosols. Results indicate that external forcing contributes to the cooling trend over East Asia. Furthermore, GHGs, and to a lesser degree the direct effects of aerosols, are the main contributors to the cooling trend. The possible linkages between the external forcings and the cooling trend are discussed. Content Type Journal Article Pages 1-13 DOI 10.1007/s10584-012-0592-4 Authors Bian He, College of Atmospheric Science, Nanjing University of Information Science & Technology, Nanjing, 210044 China Qing Bao, LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029 China Jiandong Li, LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029 China Guoxiong Wu, LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029 China Yimin Liu, LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029 China Xiaocong Wang, LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029 China Zhaobo Sun, College of Atmospheric Science, Nanjing University of Information Science & Technology, Nanjing, 210044 China Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Ensemble simulations with a coupled ocean-troposphere-stratosphere model for the pre-industrial era (1860 AD), late twentieth century (1990 AD) greenhouse gas (GHG) concentrations, the SRES scenarios B1, A1B, A2, as well as stabilization experiments up to the Twenty-third century with B1 and A1B scenario GHG concentrations at their values at 2100, have been analyzed with regard to the occurrence of major sudden stratospheric warmings (SSWs). An automated algorithm using 60°N and 10 hPa zonal wind and the temperature gradient between 60°N and the North Pole is used to identify this phenomenon in the large data set. With 1990 CO 2 concentrations (352 ppmv), the frequency of simulated SSWs in February and March is comparable to observation, but they are underestimated during November to January. All simulations show an increase in the number of SSWs from the pre-industrial period to the end of the twenty-first century, indicating that the increase of GHG is also reflected in the number of sudden warmings. However, a high variability partially masks the underlying trend. Multi-century averages during the stabilization periods indicate that the increase of SSWs is linear to the applied radiative forcing. A doubling of SSWs occurs when the GHG concentration reaches the level of the A2 scenario at the end of the twenty-first century (836 ppmv). The increase in SSWs in the projections is caused by a combination of increased wave flux from the troposphere and weaker middle atmospheric zonal winds. Content Type Journal Article Pages 1-15 DOI 10.1007/s00382-012-1530-x Authors S. Schimanke, Swedish Meteorological and Hydrological Institute, Norrköping, 60176 Sweden T. Spangehl, Freie Universität Berlin, Berlin, Germany H. Huebener, Freie Universität Berlin, Berlin, Germany U. Cubasch, Freie Universität Berlin, Berlin, Germany Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    This study compares the synoptic-dynamic relationship between two phases of the Pacific/North American (PNA) pattern and winter precipitation isotopes at 73 sites across the contiguous USA. We use the spatial pattern of isotope slope—the rate of changes in precipitation isotope ratios with distance—to identify features in the seasonal precipitation isotope fields related to climatic patterns, PNA positive and PNA negative. Our results show relationships between zones of high isotope slopes and the spatial position of the polar jet stream and juxtaposition of air masses associated with the PNA pattern. During a positive PNA winter, zones of high isotope slope in the eastern USA shift southward. This change is coincident with a southward displacement of the polar jet stream in this region, which leads to a greater frequency of polar air masses and 18 O-depleted isotope values of precipitation in the region. In the western USA, zones of high slope shift eastward during the positive PNA winter, associated with more frequent penetration of tropical air masses that bring 18 O-enriched precipitation to the region. Differences in δ 18 O/temperature relationships between the PNA-positive and -negative winters and contrasting δ 18 O/temperature behaviors in the eastern and western USA provide support for the role of variation in moisture source and transport as a control on the isotopic patterns. These findings highlight the importance of synoptic climate driven by PNA pattern in determining the spatial patterns of precipitation isotopes and provide constraints on paleo-water isotope interpretation and modern isotope hydrological processes. Content Type Journal Article Pages 1-18 DOI 10.1007/s00382-012-1548-0 Authors Zhongfang Liu, Tianjin Key Laboratory of Water Resource and Environment, Tianjin Normal University, Tianjin, China Gabriel J. Bowen, Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, IN, USA Jeffrey M. Welker, Environment and Natural Resources Institute, University of Alaska Anchorage, Anchorage, AK, USA Kei Yoshimura, Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Climate change and biological invasions are major causes of biodiversity loss and may also have synergistic effects, such as range shifts of invaders due to changing climate. Bioclimatic models provide an important tool to assess how the threat of invasive species may change with altered temperature and precipitation regimes. In this study, potential distributions of three recently naturalised plant species in New Zealand are modelled ( Archontophoenix cunninghamiana , Psidium guajava and Schefflera actinophylla ), using four different general circulation models (CCCMA-CGCM3, CSIRO-Mk3.0, GFDL-CM2.0 and UKMO-HADCM3) with two emission scenarios (A2 and B1) each. Based on a maximum entropy approach, models were trained on global data using a small set of uncorrelated predictors. The models were projected to the country of interest, using climate models that had been statistically downscaled to New Zealand, in order to obtain high resolution predictions. This study provides evidence of the potential range expansion of these species, with potentially suitable habitat increasing by as much as 169 % ( A. cunninghamiana; with up to 115,805 km 2 of suitable habitat), 133 % ( P. guajava; 164,450 km 2 ) and 208 % ( S. actinophylla; 31,257 km 2 ) by the end of the century compared to the currently suitable habitat. The results show that while predictions vary depending on the chosen climate scenario, there is remarkable consistency amongst most climate models within the same emission scenario, with overlaps in areas of predicted presence ranging between 81 % and 99.5 % (excluding CSIRO-Mk3.0). By having a better understanding of how climate change will affect distribution of invasive plants, appropriate management measures can be taken. Content Type Journal Article Pages 1-13 DOI 10.1007/s10584-012-0605-3 Authors Christine S. Sheppard, Centre for Biodiversity and Biosecurity, School of Biological Sciences, The University of Auckland, Private Bag 92019, Auckland, 1142 New Zealand Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    100-year Global Warming Potentials (GWPs) are used almost universally to compare emissions of greenhouse gases in national inventories and reduction targets. GWPs have been criticised on several grounds, but little work has been done to determine global mitigation costs under alternative physics-based metrics . We used the integrated assessment model MESSAGE to compare emission pathways and abatement costs for fixed and time-dependent variants of the Global Temperature Change Potential (GTP) with those based on GWPs, for a policy goal of limiting the radiative forcing to a specified level in the year 2100. We find that fixed 100-year GTPs would increase global abatement costs (discounted and aggregated over the 21 st century) under this policy goal by 5–20 % relative to 100-year GWPs, whereas time-varying GTPs would reduce costs by about 5 %. These cost differences are smaller than differences arising from alternative assumptions regarding agricultural mitigation potential and much smaller than those arising from alternative radiative forcing targets. Using the land-use model GLOBIOM, we show that alternative metrics affect food production differently in different world regions depending on regional characteristics of future land-use change to meet growing food demand. We conclude that under scenarios of complete participation, the choice of metric has a limited impact on global abatement costs but could be important for the political economy of regional and sectoral participation in collective mitigation efforts, in particular changing costs and gains over time for agriculture and energy-intensive sectors. Content Type Journal Article Pages 1-14 DOI 10.1007/s10584-012-0593-3 Authors A. Reisinger, New Zealand Agricultural Greenhouse Gas Research Centre, Wellington, New Zealand P. Havlik, International Institute for Applied Systems Analysis, Laxenburg, Austria K. Riahi, International Institute for Applied Systems Analysis, Laxenburg, Austria O. van Vliet, International Institute for Applied Systems Analysis, Laxenburg, Austria M. Obersteiner, International Institute for Applied Systems Analysis, Laxenburg, Austria M. Herrero, International Livestock Research Institute, Nairobi, Kenya Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Meteorology is the driving force for lake internal heating, cooling, mixing, and circulation. Thus continued global warming will affect the lake thermal properties, water level, internal nutrient loading, nutrient cycling, food-web characteristics, fish-habitat, aquatic ecosystem, and other important features of lake limnology. Using a 1-D numerical model—the Lake Clarity Model (LCM) —together with the down-scaled climatic data of the two emissions scenarios (B1 and A2) of the Geophysical Fluid Dynamics Laboratory (GFDL) Global Circulation Model, we found that Lake Tahoe will likely cease to mix to the bottom after about 2060 for A2 scenario, with an annual mixing depth of less than 200 m as the most common value. Deep mixing, which currently occurs on average every 3–4 years, will (under the GFDL B1 scenario) occur only four times during 2061 to 2098. When the lake fails to completely mix, the bottom waters are not replenished with dissolved oxygen and eventually dissolved oxygen at these depths will be depleted to zero. When this occurs, soluble reactive phosphorus (SRP) and ammonium-nitrogen (both biostimulatory) are released from the deep sediments and contribute approximately 51 % and 14 % of the total SRP and dissolved inorganic nitrogen load, respectively. The lake model suggests that climate change will drive the lake surface level down below the natural rim after 2085 for the GFDL A2 but not the GFDL B1 scenario. The results indicate that continued climate changes could pose serious threats to the characteristics of the Lake that are most highly valued. Future water quality planning must take these results into account. Content Type Journal Article Pages 1-25 DOI 10.1007/s10584-012-0600-8 Authors G. B. Sahoo, Tahoe Environmental Research Center, University of California Davis, One Shields Avenue, Davis, CA 95616, USA S. G. Schladow, Tahoe Environmental Research Center, University of California Davis, One Shields Avenue, Davis, CA 95616, USA J. E. Reuter, Tahoe Environmental Research Center, University of California Davis, One Shields Avenue, Davis, CA 95616, USA R. Coats, Department of Environmental Science and Policy, University of California Davis, One Shields Avenue, Davis, CA 95616, USA M. Dettinger, US Geological Survey and Scripps Institute of Oceanography, La Jolla, CA 92093, USA J. Riverson, Tetra Tech, Inc., 10306 Eaton Place, Suite 340, Fairfax, VA 22030, USA B. Wolfe, Northwest Hydraulic Consultants, 870 Emerald Bay Road, Suite 308, South Lake Tahoe, CA 96150, USA M. Costa-Cabral, Hydrology Futures, LLC, 4509 Interlake Avenue N #300, Seattle, WA 98103, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Tundra and taiga ecosystems comprise nearly 40 % of the terrestrial landscapes of Canada. These permafrost ecosystems have supported humans for more than 4500 years, and are currently home to ca. 115,000 people, the majority of whom are First Nations, Inuit and Métis. The responses of these ecosystems to the regional warming over the past 30–50 years were the focus of four Canadian IPY projects. Northern residents and researchers reported changes in climate and weather patterns and noted shifts in vegetation and other environmental variables. In forest-tundra areas tree growth and reproductive effort correlated with temperature, but seedling establishment was often hindered by other factors resulting in site-specific responses. Increased shrub cover has occurred in sites across the Arctic at the plot and landscape scale, and this was supported by results from experimental warming. Experimental warming increased vegetation cover and nutrient availability in most tundra soils; however, resistance to warming was also found. Soil microbial diversity in tundra was no different than in other biomes, although there were shifts in mycorrhizal diversity in warming experiments. All sites measured were sinks for carbon during the growing season, with expected seasonal and latitudinal patterns. Modeled responses of a mesic tundra system to climate change showed that the sink status will likely continue for the next 50–100 years, after which these tundra systems will likely become a net source of carbon dioxide to the atmosphere. These IPY studies were the first comprehensive assessment of the state and change in Canadian northern terrestrial ecosystems and showed that the inherent variability in these systems is reflected in their site-specific responses to changes in climate. They also showed the importance of using local traditional knowledge and science, and provided extensive data sets, sites and researchers needed to study and manage the inevitable changes in the Canadian North. Content Type Journal Article Pages 1-28 DOI 10.1007/s10584-012-0587-1 Authors Gregory H. R. Henry, Department of Geography, University of British Columbia, Vancouver, BC V6T 1Z2, Canada Karen A. Harper, School for Resource and Environmental Studies, Dalhousie University, Halifax, NS B3H 4R2, Canada Wenjun Chen, Canadian Centre for Remote Sensing, Natural Resources Canada, Ottawa, ON K1A 0Y7, Canada Julie R. Deslippe, Department of Forest Science, University of British Columbia, Vancouver, BC V6T 1Z4, Canada Robert F. Grant, Department of Renewable Resources, University of Alberta, Edmonton, AB T6G 2E3, Canada Peter M. Lafleur, Department of Geography, Trent University, Peterborough, ON K9J 7B8, Canada Esther Lévesque, Département de chimie-biologie, Université du Québec à Trois-Rivières, Trois-Rivières, QC G9A 5H7, Canada Steven D. Siciliano, Department of Soil Science, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada Suzanne W. Simard, Department of Forest Science, University of British Columbia, Vancouver, BC V6T 1Z4, Canada Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Scenarios exist so that decision makers and those who provide them with information can make statements about the future that claim less confidence than do predictions, projections, and forecasts. Despite their prevalence, fundamental questions remain about how scenarios should best be developed and used. This paper proposes a particular conceptualization of scenarios that aims to address many of the challenges faced when using scenarios to inform contentious policy debates. The concept envisions scenarios as illuminating the vulnerabilities of proposed policies, that is, as concise summaries of the future states of the world in which a proposed policy would fail to meet its goals. Such scenarios emerge from a decision support process that begins with a proposed policy, seeks to understand the conditions under which it would fail, and then uses this information to identify and evaluate potential alternative policies that are robust over a wide range of future conditions. Statistical cluster analyses applied to databases of simulation model results can help identify scenarios as part of this process. Drawing on themes from the decision support literature, this paper first reviews difficulties faced when using scenarios to inform climate-related decisions, describes the proposed approach to address these challenges, illustrates the approach with applications for three different types of users, and concludes with some thoughts on implications for the provision of climate information and for future scenario processes. Content Type Journal Article Pages 1-20 DOI 10.1007/s10584-012-0574-6 Authors Robert Lempert, RAND, 1776 Main St., Santa Monica, CA 90407, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Canada’s IPY program funded seven marine projects spanning the North American Arctic. Work embraced oceanography, air-sea interactions, storm response, paleo-climate and trace-element chemistry. Notable findings are emerging. Conditions in the Beaufort were unusual in 2007, with very high air pressure bringing strong winds, rapid ice drift, thin winter ice, enhanced shelf-break upwelling and a maximum in freshwater retention in the Beaufort Gyre. A mapping of trace chemicals suggests that Arctic mid-depth circulation may also have reversed. Study of Canadian Arctic through-flow revealed a net annual seawater export of 44,000 cubic kilometres from the Arctic to Baffin Bay. Observations of sea ice, sustained through the IPY, affirmed that ice cover is the key attribute of Arctic seas, with wind as a potent agent in its variation. Surveys have shown that the anthropogenic decline in seawater alkalinity is aggravated in the Arctic by low temperature and low salinity resulting from ice melt. Careful experiments have revealed that Arctic phytoplankton growth is constrained by scarcity of dissolved iron where light levels are low. A manganese fingerprint in sediments has tracked changing sea level during the Ice Age. Sediment-core analysis has revealed the Arctic Oscillation as a dominant cause of long-period climate variations during the Holocene. One project has demonstrated how multi-tasked vessels can maintain a watch on Canada’s Arctic within a reliable affordable logistic framework, while a wave forecast model developed by another for the Beaufort is suitable for operational use. Content Type Journal Article Pages 1-25 DOI 10.1007/s10584-012-0576-4 Authors H. Melling, Fisheries and Oceans Canada, Institute of Ocean Sciences, PO Box 6000, Sidney, BC, Canada V8L 4B2 R. Francois, Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, BC, Canada V6T 1Z4 P. G. Myers, Department Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB, Canada T6G 2E3 W. Perrie, Fisheries and Oceans Canada, Bedford Institute of Oceanography, 1 Challenger Drive, Dartmouth, NS, Canada B2Y 4A2 A. Rochon, Institut des sciences de la mer de Rimouski (ISMER), Université du Québec à Rimouski, Rimouski, QC, Canada G5L 3A1 R. L. Taylor, Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, BC, Canada V6T 1Z4 Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    While previous research has documented marine fish and invertebrates shifting poleward in response to warming climates, less is known about the response of fisheries to these changes. By examining fisheries in the northeastern United States over the last four decades of warming temperatures, we show that northward shifts in species distributions were matched by corresponding northward shifts in fisheries. The proportion of warm-water species caught in most states also increased through time. Most importantly, however, fisheries shifted only 10–30 % as much as their target species, and evidence suggested that economic and regulatory constraints played important roles in creating these lags. These lags may lead to overfishing and population declines if not accounted for in fisheries management and climate adaptation. In coupled natural-human systems such as fisheries, human actions play important roles in determining the sustainability of the system and, therefore, future conservation and climate mitigation planning will need to consider not only biophysical changes, but also human responses to these changes and the feedbacks that these responses have on ecosystems. Content Type Journal Article Category Letter Pages 1-9 DOI 10.1007/s10584-012-0599-x Authors Malin L. Pinsky, Department of Ecology and Evolutionary Biology, Princeton University, 106A Guyot Hall, Princeton, NJ 08540, USA Michael Fogarty, Northeast Fisheries Science Center, National Marine Fisheries Service, Woods Hole, MA 02543, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    The social and cultural dimensions of arctic environmental change were explored through Canada’s International Polar Year (IPY) research program. Drawing on concepts of vulnerability, resilience and human security, we discuss preliminary results of 15 IPY research projects (of 52) which dealt with the effects and responses of northern communities to issues of ecological variability, natural resource development and climate change. This paper attempts to determine whether the preliminary results of these projects have contributed to the IPY program goal of building knowledge about well-being in the arctic. The projects were diverse in focus and approach but together offer a valuable pan-northern perspective on many themes including land and resource use, food security, poverty and best practices of northern engagement. Case study research using self-reported measures suggests individual views of their own well-being differ from regional and territorial standardized statistics on quality of life. A large body of work was developed around changes in land and resource use. A decline in land and resource use in some areas and consequent concerns for food security, are directly linked to the effects of climate change, particularly in coastal areas where melting sea ice, erratic weather events and changes in the stability of landscapes (e.g., erosion, slumping) are leading to increased risks for land users. Natural resource development, while creating some new economic opportunities, may be compounding rather than offsetting such stresses of environmental change for vulnerable populations. While the IPY program has contributed to our understanding of some aspects of well-being in the arctic, many other issues of social, economic, cultural and political significance, including those unrelated to environmental change, remain poorly understood. Content Type Journal Article Pages 1-22 DOI 10.1007/s10584-012-0588-0 Authors Brenda Parlee, Faculty of Native Studies, Faculty of Agricultural, Life and Environmental Sciences, University of Alberta, 1-09 Pembina Hall, Edmonton, Alberta T6G 2H1, Canada Chris Furgal, Indigenous Environmental Studies Program, Trent University, 1600 West Bank Dr, Peterborough, ON K9J 7B8 Canada Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    The goal of this paper is to provide information on the sea level and upper ocean temperature variability and trends in the Cook Islands region within a global context. Oceanic fisheries variability and change take place within the physical environment. Because the state of the historical data set is not as would be desired, we begin with some review of data distribution issues. We provide some new results from the Cook Islands region but draw upon previous work for information about the global and ocean-basin scale context. There are clear trends over recent decades in sea level and, generally, in upper ocean temperature, but there is also substantial interannual and interdecadal variability, which are larger locally than globally. Because of this variability, it is not possible to say if recent Cook Islands regional trends are representative of longer-term trends, or if longer-term trends have increased recently. Trends in the Cook Islands region over the last four decades are ~0.1–0.3 °C per decade in near surface temperature and ~2–3 cm sea level per decade. Content Type Journal Article Pages 1-12 DOI 10.1007/s10584-012-0580-8 Authors D. E. Harrison, NOAA/PMEL and University of Washington, Seattle, WA, USA Mark Carson, University of Hamburg, KlimaCampus, Hamburg, Germany Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    The effects of the northeastern Eurasian snow cover on the frequency of spring dust storms in northwestern China have been examined for the period 1979–2007. Averaged over all 43 stations in northwestern China, a statistically significant relationship has been found between dust-storm frequency (DSF) and Eurasian snow-water equivalent (SWE) during spring: mean DSF of 7.4 and 3.3 days for years of high- and low SWE, respectively. Further analyses reveal that positive SWE anomalies enhance the meridional gradients of the lower tropospheric temperatures and geopotential heights, thereby strengthening westerly jets and zonal wind shear over northwestern China and western Inner Mongolia of China, the regions of major dust sources. The anomalous atmospheric circulation corresponding to the Eurasian SWE anomalies either reinforces or weakens atmospheric baroclinicity and cyclogenesis, according to the sign of the anomaly, to affect the spring DSF. This study suggests that Eurasian SWE anomalies can be an influential factor of spring DSF in northwestern China and western Inner Mongolia of China. Content Type Journal Article Pages 1-13 DOI 10.1007/s00382-012-1522-x Authors Yun Gon Lee, Climate Physics Laboratory, School of Earth and Environmental Sciences, Seoul National University, Seoul, 151-747 Korea Chang-Hoi Ho, Climate Physics Laboratory, School of Earth and Environmental Sciences, Seoul National University, Seoul, 151-747 Korea Jhoon Kim, Department of Atmospheric Sciences, Yonsei University, Seoul, Korea Jinwon Kim, Department of Atmospheric and Oceanic Sciences and Joint Institute for Regional Earth System Science and Engineering, University of California Los Angeles, Los Angeles, CA, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Regional climate models (RCMs) have been increasingly used for climate change studies at the watershed scale. However, their performance is strongly dependent upon their driving conditions, internal parameterizations and domain configurations. Also, the spatial resolution of RCMs often exceeds the scales of small watersheds. This study developed a two-step downscaling method to generate climate change projections for small watersheds through combining a weighted multi-RCM ensemble and a stochastic weather generator. The ensemble was built on a set of five model performance metrics and generated regional patterns of climate change as monthly shift terms. The stochastic weather generator then incorporated these shift terms into observed climate normals and produced synthetic future weather series at the watershed scale. This method was applied to the Assiniboia area in southern Saskatchewan, Canada. The ensemble led to reduced biases in temperature and precipitation projections through properly emphasizing models with good performance. Projection of precipitation occurrence was particularly improved through introducing a weight-based probability threshold. The ensemble-derived climate change scenario was well reproduced as local daily weather series by the stochastic weather generator. The proposed combination of dynamical downscaling and statistical downscaling can improve the reliability and resolution of future climate projection for small prairie watersheds. It is also an efficient solution to produce alternative series of daily weather conditions that are important inputs for examining watershed responses to climate change and associated uncertainties. Content Type Journal Article Pages 1-17 DOI 10.1007/s00382-012-1490-1 Authors Hua Zhang, Institute for Energy, Environment and Sustainable Communities, University of Regina, Regina, SK S4S 0A2, Canada Guo H. Huang, Institute for Energy, Environment and Sustainable Communities, University of Regina, Regina, SK S4S 0A2, Canada Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Regional climate models represent a promising tool to assess the regional dimension of future climate change and are widely used in climate impact research. While the added value of regional climate models has been highlighted with respect to a better representation of land-surface interactions and atmospheric processes, it is still unclear whether radiative heating implies predictability down to the typical scale of a regional climate model. As a quantitative assessment, we apply an optimal statistical filter to compare the coherence between observed and simulated patterns of Mediterranean climate change from a global and a regional climate model. It is found that the regional climate model has indeed an added value in the detection of regional climate change, contrary to former assumptions. The optimal filter may also serve as a weighting factor in multi-model averaging. Content Type Journal Article Pages 1-10 DOI 10.1007/s00382-012-1517-7 Authors Heiko Paeth, Institute of Geography and Geology, University of Würzburg, Am Hubland, 97074 Würzburg, Germany Birgit Mannig, Institute of Geography and Geology, University of Würzburg, Am Hubland, 97074 Würzburg, Germany Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The variability of the European climate is mostly controlled by the unstable nature of the North-Atlantic dynamics, especially in wintertime. The intra-seasonal to inter-annual fluctuations of atmospheric circulations has often been described as the alternation between a limited number of preferential weather regimes. Such discrete description can be justified by the multi-modality of the latitudinal position of the jet stream. In addition, seasonal extremes in European temperatures are generally associated with an exceptional persistence into one weather regime. Here we investigate the skill of the IPSL model to both simulate North-Atlantic weather regimes and European temperature extremes, including summer heat waves and winter cold spells. We use a set of eight IPSL experiments, with six different horizontal resolutions and the two versions used in CMIP3 and CMIP5. We find that despite a substantial deficit in the simulated poleward peak of the jet stream, the IPSL model represents weather regimes fairly well. A significant improvement is found for all horizontal resolutions higher than the one used in CMIP3, while the increase in vertical resolution included in the CMIP5 version tends to improve the wintertime dynamics. In addition to a recurrent cold bias over Europe, the IPSL model generally overestimates (underestimates) the indices of winter cold spells (summer heat waves) such as frequencies or durations. We find that the increase in horizontal resolution almost always improves these statistics, while the influence of vertical resolution is less clear. Overall, the CMIP5 version of the IPSL model appears to carry promising improvements in the simulation of the European climate variability. Content Type Journal Article Pages 1-18 DOI 10.1007/s00382-012-1529-3 Authors Julien Cattiaux, IPSL/LSCE, Unité mixte CEA-CNRS-UVSQ, Orme des Merisiers, 91191 Gif-sur-Yvette Cedex, France Benjamin Quesada, IPSL/LSCE, Unité mixte CEA-CNRS-UVSQ, Orme des Merisiers, 91191 Gif-sur-Yvette Cedex, France Ara Arakélian, IPSL/LMD, Unité mixte Ecole Polytechnique-CNRS-ENS-UPMC, 75005 Paris, France Francis Codron, IPSL/LMD, Unité mixte Ecole Polytechnique-CNRS-ENS-UPMC, 75005 Paris, France Robert Vautard, IPSL/LSCE, Unité mixte CEA-CNRS-UVSQ, Orme des Merisiers, 91191 Gif-sur-Yvette Cedex, France Pascal Yiou, IPSL/LSCE, Unité mixte CEA-CNRS-UVSQ, Orme des Merisiers, 91191 Gif-sur-Yvette Cedex, France Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    A dynamical wave model implemented over the North Pacific Ocean was forced with winds from three coupled global climate models (CGCMs) run under a medium-to-high scenario for greenhouse gas emissions through the twenty-first century. The results are analyzed with respect to changes in upper quantiles of significant wave height (90th and 99th percentile H S ) during boreal winter. The three CGCMs produce surprisingly similar patterns of change in winter wave climate during the century, with waves becoming 10–15 % smaller over the lower mid-latitudes of the North Pacific, particularly in the central and western ocean. These decreases are closely associated with decreasing windspeeds along the southern flank of the main core of the westerlies. At higher latitudes, 99th percentile wave heights generally increase, though the patterns of change are less uniform than at lower latitudes. The increased wave heights at high latitudes appear to be due a variety of wind-related factors including both increased windspeeds and changes in the structure of the wind field, these varying from model to model. For one of the CGCMs, a commonly used statistical approach for estimating seasonal quantiles of H S on the basis of seasonal mean sea level pressure (SLP) is used to develop a regression model from 60 years of twentieth century data as a training set, and then applied using twenty-first century SLP data. The statistical model reproduces the general pattern of decreasing twenty-first century wave heights south of ~40 N, but underestimates the magnitude of the changes by ~50–70 %, reflecting relatively weak coupling between sea level pressure and wave heights in the CGCM data and loss of variability in the statistically projected wave heights. Content Type Journal Article Pages 1-26 DOI 10.1007/s00382-012-1435-8 Authors Nicholas E. Graham, Hydrologic Research Center, San Diego, CA, USA Daniel R. Cayan, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA Peter D. Bromirski, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA Reinhard E. Flick, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    This study estimates MJO change under the A1B greenhouse gas emission scenario using the ECHAM5 AGCM whose coupled version (ECHAM5/MPI-OM) has simulated best MJO variance among fourteen CGCMs. The model has a horizontal resolution at T319 (about 40 km) and is forced by the monthly evolving SST derived from the ECHAM5/MPI-OM at a lower resolution of T63 (about 200 km). Two runs are carried out covering the last 21 years of the twentieth and twenty-first centuries. The NCEP/NCAR Reanalysis products and observed precipitation are used to validate the simulated MJO during the twentieth century, based on which the twenty-first century MJO change is compared and predicted. The validation indicates that the previously reported MJO variances in the T63 coupled version are reproduced by the 40-km ECHAM5. More aspects of MJO, such as the eastward propagation, structure, and dominant frequency and zonal wavenumber in power spectrum, are simulated reasonably well. The magnitude in power, however, is still low so that the signal is marginally detectable and embedded in the over-reddened background. Under the A1B scenario, the T63 ECHAM5/MPI-OM projected an over 3 K warmer tropical sea surface that forces the 40-km ECHAM to produce wetter tropics. The enhanced precipitation variance shows more spectral enhancement in background than in most wavebands. The zonal winds associated with MJO, however, are strengthened in the lower troposphere but weakened in the upper. On the one hand, the 850-hPa zonal wind has power nearly doubled in 30–60-days bands, demonstrating relatively clearer enhancement than the precipitation in MJO with the warming. A 1-tailed Student’s t test suggests that most of the MJO changes in variance and power spectra are statically significant. Subject to a 20–100-days band-pass filtering of that wind, an EOF analysis indicates that the two leading components in the twentieth-century run have a close structure to but smaller percentage of explained-to-total variance than those in observations; the A1B warming slightly increases the explained percentage and alters the structure. An MJO index formed by the two leading principal components discloses nearly doubling in the number of prominent MJO events with a peak phase occurring in February and March. A composite MJO life cycle of these events favors the frictional moisture convergence mechanism in maintaining the MJO and the nonlinear wind-induced surface heat exchange (WISHE) mechanism also appears in the A1B warming case. On the other hand, the Slingo index based on the 300-hPa zonal wind discloses that the upper-level MJO tends to be suppressed by the A1B warming, although the loose relationship with ENSO remains unchanged. Possible cause for the different change of MJO in the lower and upper troposphere is discussed. Content Type Journal Article Pages 1-15 DOI 10.1007/s00382-012-1532-8 Authors Ping Liu, International Pacific Research Center, SOEST, University of Hawaii at Manoa, Honolulu, HI, USA Tim Li, International Pacific Research Center, SOEST, University of Hawaii at Manoa, Honolulu, HI, USA Bin Wang, International Pacific Research Center, SOEST, University of Hawaii at Manoa, Honolulu, HI, USA Minghua Zhang, School of Marine and Atmospheric Sciences, Stony Brook University, 199 Endeavour Hall, SoMAS, Stony Brook, NY 11794-5000, USA Jing-jia Luo, Research Institution for Global Change, Japan Agency for Marine-Earth Science and Technology, Kanagawa, Japan Yukio Masumoto, Research Institution for Global Change, Japan Agency for Marine-Earth Science and Technology, Kanagawa, Japan Xiaocong Wang, The State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Beijing, China Erich Roeckner, Max Planck Institute for Meteorology, Hamburg, Germany Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The small but stubbornly unyielding possibility of a very large long-term response of global temperature to increases in atmospheric carbon dioxide can be termed the fat tail of high climate sensitivity. Recent economic analyses suggest that the fat tail should dominate a rational policy strategy if the damages associated with such high temperatures are large enough. The conclusions of such analyses, however, depend on how economic growth, temperature changes, and climate damages unfold and interact over time. In this paper we focus on the role of two robust physical properties of the climate system: the enormous thermal inertia of the ocean, and the long timescales associated with high climate sensitivity. Economic models that include a climate component, and particularly those that focus on the tails of the probability distributions, should properly represent the physics of this slow response to high climate sensitivity, including the correlated uncertainty between present forcing and climate sensitivity, and the global energetics of the present climate state. If climate sensitivity in fact proves to be high, these considerations prevent the high temperatures in the fat tail from being reached for many centuries. A failure to include these factors risks distorting the resulting economic analyses. For example, we conclude that fat-tail considerations will not strongly influence economic analyses when these analyses follow the common—albeit controversial—practices of assigning large damages only to outcomes with very high temperature changes and of assuming a significant baseline level of economic growth. Content Type Journal Article Pages 1-16 DOI 10.1007/s10584-012-0582-6 Authors Gerard H. Roe, Department of Earth and Space Sciences, University of Washington, Seattle, WA, USA Yoram Bauman, Program on the Environment, University of Washington, Seattle, WA, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    This paper aims at characterizing how different key cloud properties (cloud fraction, cloud vertical distribution, cloud reflectance, a surrogate of the cloud optical depth) vary as a function of the others over the tropical oceans. The correlations between the different cloud properties are built from 2 years of collocated A-train observations (CALIPSO-GOCCP and MODIS) at a scale close to cloud processes; it results in a characterization of the physical processes in tropical clouds, that can be used to better understand cloud behaviors, and constitute a powerful tool to develop and evaluate cloud parameterizations in climate models. First, we examine a case study of shallow cumulus cloud observed simultaneously by the two sensors (CALIPSO, MODIS), and develop a methodology that allows to build global scale statistics by keeping the separation between clear and cloudy areas at the pixel level (250, 330 m). Then we build statistical instantaneous relationships between the cloud cover, the cloud vertical distribution and the cloud reflectance. The vertical cloud distribution indicates that the optically thin clouds (optical thickness 〈1.5) dominate the boundary layer over the trade wind regions. Optically thick clouds (optical thickness 〉3.4) are composed of high and mid-level clouds associated with deep convection along the ITCZ and SPCZ and over the warm pool, and by stratocumulus low level clouds located along the East coast of tropical oceans. The cloud properties are analyzed as a function of the large scale circulation regime. Optically thick high clouds are dominant in convective regions (CF 〉 80 %), while low level clouds with low optical thickness (〈3.5) are present in regimes of subsidence but in convective regimes as well, associated principally to low cloud fractions (CF 〈 50 %). A focus on low-level clouds allows us to quantify how the cloud optical depth increases with cloud top altitude and with cloud fraction. Content Type Journal Article Pages 1-18 DOI 10.1007/s00382-012-1533-7 Authors Dimitra Konsta, LMD, Ecole Polytechnique, Palaiseau, France Helene Chepfer, LMD/IPSL, Universite Pierre et Marie Curie, Paris, France Jean-Louis Dufresne, LMD/IPSL, CNRS, Universite Pierre et Marie Curie, Paris, France Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The Greenland ice sheet is projected to be strongly affected by global warming. These projections are either issued from downscaling methods (such as Regional Climate Models) or they come directly from General Circulation Models (GCMs). In this context, it is necessary to evaluate the accuracy of the daily atmospheric circulation simulated by the GCMs, since it is used as forcing for downscaling methods. Thus, we use an automatic circulation type classification based on two indices (Euclidean distance and Spearman rank correlation using the daily 500 hPa geopotential height) to evaluate the ability of the GCMs from both CMIP3 and CMIP5 databases to simulate the main circulation types over Greenland during summer. For each circulation type, the GCMs are compared to three reanalysis datasets on the basis of their frequency and persistence differences. For the current climate (1961–1990), we show that most of the GCMs do not reproduce the expected frequency and the persistence of the circulation types and that they simulate poorly the observed daily variability of the general circulation. Only a few GCMs can be used as reliable forcings for downscaling methods over Greenland. Finally, when applying the same approach to the future projections of the GCMs, no significant change in the atmospheric circulation over Greenland is detected, besides a generalised increase of the geopotential height due to a uniform warming of the atmosphere. Content Type Journal Article Pages 1-20 DOI 10.1007/s00382-012-1538-2 Authors Alexandre Belleflamme, Laboratory of Climatology and Topoclimatology, University of Liège, Allée du 6 Aout, 2, 4000 Liège, Belgium Xavier Fettweis, Laboratory of Climatology and Topoclimatology, University of Liège, Allée du 6 Aout, 2, 4000 Liège, Belgium Charlotte Lang, Laboratory of Climatology and Topoclimatology, University of Liège, Allée du 6 Aout, 2, 4000 Liège, Belgium Michel Erpicum, Laboratory of Climatology and Topoclimatology, University of Liège, Allée du 6 Aout, 2, 4000 Liège, Belgium Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Portions of the southern and southeastern United States, primarily Mississippi, Alabama, and Georgia, have experienced century-long (1895–2007) downward air temperature trends that occur in all seasons. Superimposed on them are shifts in mean temperatures on decadal scales characterized by alternating warm (1930s–1940s, 1990s) and cold (1900s; 1960s–1970s) regimes. Regional atmospheric circulation and SST teleconnection indices, station-based cloud cover and soil moisture (Palmer drought severity index) data are used in stepwise multiple linear regression models. These models identify predictors linked to observed winter, summer, and annual Southeastern air temperature variability, the observed variance (r 2 ) they explain, and the resulting prediction and residual time series. Long-term variations and trends in tropical Pacific sea temperatures, cloud cover, soil moisture and the North Atlantic and Arctic oscillations account for much of the air temperature downtrends. Soil moisture and cloud cover are the primary predictors of 59.6 % of the observed summer temperature variance. While the teleconnections, cloud cover and moisture data account for some of the annual and summer Southeastern cooling trend, large significant downward trending residuals remain in winter and summer. Comparison is made to the northeastern United States where large twentieth century upward air temperature trends are driven by cloud cover increases and Atlantic Multidecadal Oscillation (AMO) variability. Differences between the Northeastern warming and the Southeastern cooling trends in summer are attributable in part to the differing roles of cloud cover, soil moisture, the Arctic Oscillation and the AMO on air temperatures of the 2 regions. Content Type Journal Article Pages 1-12 DOI 10.1007/s00382-012-1437-6 Authors Jeffrey C. Rogers, Department of Geography and Atmospheric Sciences Program, The Ohio State University, Columbus, OH 43210-1361, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Northern China has been subject to increased heatwave frequency (HWF) in recent decades, which deteriorates the local droughts and desertification. More than half a billion people face drinking water shortages and worsening ecological environment. In this study, the variability in the western Tibetan Plateau snow cover (TPSC) is observed to have an intimate linkage with the first empirical orthogonal function mode of the summer HWF across China. This distinct leading mode is dominated by the decadal to inter-decadal variability and features a mono-sign pattern with the extreme value center prevailing over northern China and high pressure anomalies at mid- and upper troposphere over Mongolia and the adjacent regions. A simplified general circulation model is utilized to examine the possible physical mechanism. A reduced TPSC anomaly can induce a positive geopotential height anomaly at the mid- and upper troposphere and subsequently enhance the climatological high pressure ridge over Mongolia and the adjacent regions. The subsidence associated with the high pressure anomalies tends to suppress the local cloud formation, which increases the net radiation budget, heats the surface, and favors more heatwaves. On the other hand, the surface heating can excite high pressure anomalies at mid- and upper troposphere. The latter further strengthens the upper troposphere high pressure anomalies over Mongolia and the adjacent regions. Through such positive feedback effect, the TPSC is tied to the interdecadal variations of the northern China HWF. Content Type Journal Article Category Original Article Pages 1-10 DOI 10.1007/s00382-012-1439-4 Authors Zhiwei Wu, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing, China Zhihong Jiang, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing, China Jianping Li, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China Shanshan Zhong, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing, China Lijuan Wang, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing, China Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The regional ocean modeling system is used, at a resolution of 1/12°, to explicitly simulate the ocean circulation near the Iberian coast during two 30-year simulations forced by atmospheric fields produced by the RACMO regional climate model. The first simulation is a control run for the present climate (1961–1990) and the second is a scenario run from the IPCC A2 scenario (2071–2100). In the control run, the model reproduces some important features of the regional climate but with an overestimation of upwelling intensity, mainly attributable to inaccuracies in the coastal wind distributions when compared against reanalysis data. A comparison between the scenario and control simulations indicates a significant increase in coastal upwelling, with more frequent events with higher intensity, leading to an overall enhancement of SST variability on both the intra- and inter-annual timescales. The increase in upwelling intensity is more prominent in the northern limit of the region, near cape Finisterre, where its mean effect extends offshore for a few hundred kms, and is able to locally cancel the effect of global warming. If these results are confirmed, climate change will have a profound impact on the regional marine ecosystem. Content Type Journal Article Pages 1-12 DOI 10.1007/s00382-012-1442-9 Authors P. M. A. Miranda, Instituto Dom Luiz, University of Lisbon, Lisbon, Portugal J. M. R. Alves, Instituto Dom Luiz, University of Lisbon, Lisbon, Portugal N. Serra, Institut für Meereskunde, University of Hamburg, Hamburg, Germany Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    A wide range of statistical tools is used to investigate the decadal variability of the Atlantic Meridional Overturning Circulation (AMOC) and associated key variables in a climate model (CHIME, Coupled Hadley-Isopycnic Model Experiment), which features a novel ocean component. CHIME is as similar as possible to the 3rd Hadley Centre Coupled Model (HadCM3) with the important exception that its ocean component is based on a hybrid vertical coordinate. Power spectral analysis reveals enhanced AMOC variability for periods in the range 15–30 years. Strong AMOC conditions are associated with: (1) a Sea Surface Temperature (SST) anomaly pattern reminiscent of the Atlantic Multi-decadal Oscillation (AMO) response, but associated with variations in a northern tropical-subtropical gradient; (2) a Surface Air Temperature anomaly pattern closely linked to SST; (3) a positive North Atlantic Oscillation (NAO)-like pattern; (4) a northward shift of the Intertropical Convergence Zone. The primary mode of AMOC variability is associated with decadal changes in the Labrador Sea and the Greenland Iceland Norwegian (GIN) Seas, in both cases linked to the tropical activity about 15 years earlier. These decadal changes are controlled by the low-frequency NAO that may be associated with a rapid atmospheric teleconnection from the tropics to the extratropics. Poleward advection of salinity anomalies in the mixed layer also leads to AMOC changes that are linked to processes in the Labrador Sea. A secondary mode of AMOC variability is associated with interannual changes in the Labrador and GIN Seas, through the impact of the NAO on local surface density. Content Type Journal Article Pages 1-22 DOI 10.1007/s00382-012-1432-y Authors A. Persechino, Ocean and Earth Science, University of Southampton, European Way, Southampton, Hampshire, SO14 3ZH UK R. Marsh, Ocean and Earth Science, University of Southampton, European Way, Southampton, Hampshire, SO14 3ZH UK B. Sinha, National Oceanography Centre, European Way, Southampton, Hampshire, SO14 3ZH UK A. P. Megann, National Oceanography Centre, European Way, Southampton, Hampshire, SO14 3ZH UK A. T. Blaker, National Oceanography Centre, European Way, Southampton, Hampshire, SO14 3ZH UK A. L. New, National Oceanography Centre, European Way, Southampton, Hampshire, SO14 3ZH UK Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Chinese temperate grasslands play an important role in the terrestrial carbon cycle. Based on the parameterization and validation of Terrestrial Ecosystem Model (TEM, Version 5.0), we analyzed the carbon budgets of Chinese temperate grasslands and their responses to historical atmospheric CO 2 concentration and climate variability during 1951–2007. The results indicated that Chinese temperate grassland acted as a slight carbon sink with annual mean value of 7.3 T g C, ranging from -80.5 to 79.6 T g C yr -1 . Our sensitivity experiments further revealed that precipitation variability was the primary factor for decreasing carbon storage. CO 2 fertilization may increase the carbon storage (1.4 %) but cannot offset the proportion caused by climate variability (-15.3 %). Impacts of CO 2 concentration, temperature and precipitation variability on Chinese temperate grassland cannot be simply explained by the sum of the individual effects. Interactions among them increased total carbon storage of 56.6 T g C which 14.2 T g C was stored in vegetation and 42.4 T g C was stored in soil. Besides, different grassland types had different responses to climate change and CO 2 concentration. NPP and R H of the desert and forest steppes were more sensitive to precipitation variability than temperature variability while the typical steppe responded to temperature variability more sensitively than the desert and forest steppes. Content Type Journal Article Pages 1-14 DOI 10.1007/s10584-012-0533-2 Authors Xinghua Sui, State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093 China Guangsheng Zhou, Chinese Academy of Meteorological Sciences, Beijing, 100081 China Qianlai Zhuang, Department of Earth and Atmospheric Sciences and Department of Agronomy, Purdue University, West Lafayette, IN 47906, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    This study explores how global precipitation and tropospheric water vapor content vary on the interdecadal/long-term time scale during past three decades (1988–2010 for water vapor), in particular to what extent the spatial structures of their variations relate to changes in surface temperature. EOF analyses of satellite-based products indicate that the first two modes of global precipitation and columnar water vapor content anomalies are in general related to the El Niño-Southern oscillation. The spatial patterns of their third modes resemble the corresponding linear fits/trends estimated at each grid point, which roughly represent the interdecadal/long-term changes happening during the same time period. Global mean sea surface temperature (SST) and land surface temperature have increased during the past three decades. However, the water vapor and precipitation patterns of change do not reflect the pattern of warming, in particular in the tropical Pacific basin. Therefore, other mechanisms in addition to global warming likely exist to account for the spatial structures of global precipitation changes during this time period. An EOF analysis of longer-record (1949–2010) SST anomalies within the Pacific basin (60 o N–60 o S) indicates the existence of a strong climate regime shift around 1998/1999, which might be associated with the Pacific decadal variability (PDV) as suggested in past studies. Analyses indicate that the observed linear changes/trends in both precipitation and tropospheric water vapor during 1988–2010 seem to result from a combined impact of global mean surface warming and the PDV shift. In particular, in the tropical central-eastern Pacific, a band of increases along the equator in both precipitation and water vapor sandwiched by strong decreases south and north of it are likely caused by the opposite effects from global-mean surface warming and PDV-related, La Niña-like cooling in the tropical central-eastern Pacific. This narrow band of precipitation increase could also be considered an evidence for the influence of global mean surface warming. Content Type Journal Article Pages 1-14 DOI 10.1007/s00382-012-1443-8 Authors Guojun Gu, Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA Robert F. Adler, Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The identification of the land-atmosphere interactions as one of the key source of uncertainty in climate models calls for process-level assessment of the coupled atmosphere/land continental surface system in numerical climate models. To this end, we propose a novel approach and apply it to evaluate the standard and new parametrizations of boundary layer/convection/clouds in the Earth System Model (ESM) of Institut Pierre Simon Laplace (IPSL), which differentiate the IPSL-CM5A and IPSL-CM5B climate change simulations produced for the Coupled Model Inter-comparison Project phase 5 exercise. Two different land surface hydrology parametrizations are also considered to analyze different land-atmosphere interactions. Ten-year simulations of the coupled land surface/atmospheric ESM modules are confronted to observations collected at the SIRTA (Site Instrumental de Recherche par Télédection Atmosphérique), located near Paris (France). For sounder evaluation of the physical parametrizations, the grid of the model is stretched and refined in the vicinity of the SIRTA, and the large scale component of the modeled circulation is adjusted toward ERA-Interim reanalysis outside of the zoomed area. This allows us to detect situations where the parametrizations do not perform satisfactorily and can affect climate simulations at the regional/continental scale, including in full 3D coupled runs. In particular, we show how the biases in near surface state variables simulated by the ESM are explained by (1) the sensible/latent heat partitionning at the surface, (2) the low level cloudiness and its radiative impact at the surface, (3) the parametrization of turbulent transport in the surface layer, (4) the complex interplay between these processes. We also show how the new set of parametrizations can improve these biases. Content Type Journal Article Pages 1-19 DOI 10.1007/s00382-012-1469-y Authors F. Cheruy, Laboratoire de Météorologie Dynamique du CNRS, 4 Place Jussieu, case courrier 99, 75252 Paris Cedex 05, France A. Campoy, Sisyphe, UPMC/CNRS, Paris, France J.-C. Dupont, IPSL, Ecole Polytechnique, 91128 Palaiseau Cedex, France A. Ducharne, Sisyphe, UPMC/CNRS, Paris, France F. Hourdin, LMD, 4 Place Jussieu, case courrier 99, 75252 Paris Cedex 05, France M. Haeffelin, IPSL, Ecole Polytechnique, 91128 Palaiseau Cedex, France M. Chiriaco, LATMOS, Paris, France A. Idelkadi, LMD, 4 Place Jussieu, case courrier 99, 75252 Paris Cedex 05, France Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    We assess the ability of individual models (single-model ensembles) and the multi-model ensemble (MME) in the European Union-funded ENSEMBLES project to simulate the intraseasonal oscillations (ISOs; specifically in 10–20-day and 30–50-day frequency bands) of the Indian summer monsoon rainfall (ISMR) over the Western Ghats (WG) and the Bay of Bengal (BoB), respectively. This assessment is made on the basis of the dynamical linkages identified from the analysis of observations in a companion study to this work. In general, all models show reasonable skill in simulating the active and break cycles of the 30–50-day ISOs over the Indian summer monsoon region. This skill is closely associated with the proper reproduction of both the northward propagation of the intertropical convergence zone (ITCZ) and the variations of monsoon circulation in this band. However, the models do not manage to correctly simulate the eastward propagation of the 30–50-day ISOs in the western/central tropical Pacific and the eastward extension of the ITCZ in a northwest to southeast tilt. This limitation is closely associated with a limited capacity of models to accurately reproduce the magnitudes of intraseasonal anomalies of both the ITCZ in the Asian tropical summer monsoon regions and trade winds in the tropical Pacific. Poor reproduction of the activity of the western Pacific subtropical high on intraseasonal time scales also amplify this limitation. Conversely, the models make good reproduction of the WG 10–20-day ISOs. This success is closely related to good performance of the models in the representation of the northward propagation of the ITCZ, which is partially promoted by local air–sea interactions in the Indian Ocean in this higher-frequency band. Although the feature of westward propagation is generally represented in the simulated BoB 10–20-day ISOs, the air–sea interactions in the Indian Ocean are spuriously active in the models. This leads to active WG rainfall, which is not present in the observed BoB 10–20-day ISOs. Further analysis indicates that the intraseasonal variability of the ISMR is generally underrepresented in the simulations. Skill of the MME in seasonal ISMR forecasting is strongly dependent on individual model performance. Therefore, in order to improve the model skill with respect to seasonal ISMR forecasting, we suggest it is necessary to better represent the robust dynamical links between the ISOs and the relevant circulation variations, as well as the proportion of intraseasonal variability in the individual models. Content Type Journal Article Pages 1-21 DOI 10.1007/s00382-012-1476-z Authors Shujie Ma, Institut Català de Ciències del Clima (IC3), C/Doctor Trueta 203, 08005 Barcelona, Catalonia, Spain Xavier Rodó, Institut Català de Ciències del Clima (IC3), C/Doctor Trueta 203, 08005 Barcelona, Catalonia, Spain Yongjia Song, School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA Benjamin A. Cash, Center for Ocean-Land-Atmosphere Studies, Calverton, MD, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    This study investigates the space–time evolution of the East Asian winter monsoon (EAWM) and its relationship with other climate subsystems. Cyclostationary Empirical Orthogonal Function (CSEOF) analysis and the multiple regression method are used to delineate the detailed evolution of various atmospheric and surface variables in connection with the EAWM. The 120 days of winter (November 17–March 16) per year over 62 years (1948–2010) are analyzed using the NCEP daily reanalysis dataset. The first CSEOF mode of 850-hPa temperatures depicts the seasonal evolution of the EAWM. The contrast in heat capacity between the continent and the northwestern Pacific results in a differential heating in the lower troposphere. Its temporal evolution drives the strengthening and weakening of the Siberian High and the Aleutian Low. The anomalous sea level pressure pattern dictates anomalous circulation, in compliance with the geostrophic relationship. Thermal advection, in addition to net surface radiation, partly contributes to temperature variations in winter. Latent and sensible heat fluxes (thermal forcing from the ocean to the atmosphere) increase with decreased thermal advection. Anomalous upper-level circulation is closely linked to the low-level temperature anomaly in terms of the thermal wind equation. The interannual variability of the seasonal cycle of the EAWM is strongly controlled by the relative strength of the Siberian High to the Aleutian Low. A stronger than normal gradient between the two pressure systems amplifies the seasonal cycle of the EAWM. The EAWM seasonal cycle in the mid-latitude region exhibits a weak negative correlation with the Arctic Oscillation and the East Atlantic/West Russia indices. Content Type Journal Article Pages 1-16 DOI 10.1007/s00382-012-1491-0 Authors Yoojin Kim, School of Earth and Environmental Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul, 151-747 Republic of Korea Kwang-Yul Kim, School of Earth and Environmental Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul, 151-747 Republic of Korea Jong-Gap Jhun, School of Earth and Environmental Sciences, Seoul National University, 1 Gwanangno, Gwanak-gu, Seoul, 151-747 Republic of Korea Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The oceans moderate the rate and severity of climate change by absorbing massive amounts of anthropogenic CO 2 but this results in large-scale changes in seawater chemistry, which are collectively referred to as anthropogenic ocean acidification. Despite its potentially widespread consequences, the problem of ocean acidification has been largely absent from most policy discussions of CO 2 emissions, both because the science is relatively new and because the research community has yet to deliver a clear message to decision makers regarding its impacts. Here we report the results of the first expert survey in the field of ocean acidification. Fifty-three experts, who had previously participated in an IPCC workshop, were asked to assess 22 declarative statements about ocean acidification and its consequences. We find a relatively strong consensus on most issues related to past, present and future chemical aspects of ocean acidification: non-anthropogenic ocean acidification events have occurred in the geological past, anthropogenic CO 2 emissions are the main (but not the only) mechanism generating the current ocean acidification event, and anthropogenic ocean acidification that has occurred due to historical fossil fuel emissions will be felt for centuries. Experts generally agreed that there will be impacts on biological and ecological processes and biogeochemical feedbacks but levels of agreement were lower, with more variability across responses. Levels of agreement were higher for statements regarding calcification, primary production and nitrogen fixation than for those about impacts on foodwebs. The levels of agreement for statements pertaining to socio-economic impacts, such as impacts on food security, and to more normative policy issues, were relatively low. Content Type Journal Article Pages 1-14 DOI 10.1007/s10584-012-0591-5 Authors Jean-Pierre Gattuso, CNRS-INSU and Université Pierre et Marie Curie-Paris 6, Laboratoire d’Océanographie de Villefranche, BP 28, 06234 Villefranche-sur-Mer Cedex, France Katharine J. Mach, Department of Global Ecology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA 94305, USA Granger Morgan, Department of Engineering and Public Policy, Carnegie Mellon University, Pittsburgh, PA 15213, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Annex I Parties may receive credits or debits from Land Use, Land Use Change and Forestry (LULUCF) activities, contributing to achieving individual emission reduction targets. In the Durban climate negotiations, Parties agreed new LULUCF accounting rules for the second commitment period of the Kyoto Protocol (CP2). By using these new rules, this paper presents key differences among Parties at the minimum (assuming no additional action) and potential (assuming additional actions) contribution of the forest-related LULUCF activities in achieving the pledges for 2020. Overall, the potential contribution of LULUCF is relatively modest (up to about 2 % of 1990 emissions) for the EU, the Annex I Parties likely joining the CP2, and for the Annex I Parties that joined the CP1 as a whole. However, for specific Parties, LULUCF can make a substantial contribution to achieving the pledges. For New Zealand, for instance, the potential contribution of future LULUCF credits may equal 33 % of its 1990 emission level. For Australia, the pledges are expressed relative to 2000 emission levels including LULUCF emissions. Given that LULUCF emissions have strongly declined between 1990 and 2000, and a further decline in foreseen by 2020 (based on Australia’s projections), the minimum contribution of LULUCF to meet the Australian pledges appears to be about 19 % and 7 % relative to its 1990 and 2000 emission level, respectively. A further 3 % potential contribution is estimated from additional actions. Content Type Journal Article Category Letter Pages 1-9 DOI 10.1007/s10584-012-0584-4 Authors Giacomo Grassi, European Commission, Joint Research Centre, Institute for Environment and Sustainability, Via E. Fermi 2749, I-21027 Ispra, (VA), Italy Michel G. J. den Elzen, Department of Climate, Air and Energy, Netherlands Environmental Assessment Agency (PBL), P.O. Box 303, 3720 AH Bilthoven, The Netherlands Andries F. Hof, Department of Climate, Air and Energy, Netherlands Environmental Assessment Agency (PBL), P.O. Box 303, 3720 AH Bilthoven, The Netherlands Roberto Pilli, European Commission, Joint Research Centre, Institute for Environment and Sustainability, Via E. Fermi 2749, I-21027 Ispra, (VA), Italy Sandro Federici, European Commission, Joint Research Centre, Institute for Environment and Sustainability, Via E. Fermi 2749, I-21027 Ispra, (VA), Italy Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Climate change presents an emerging challenge to the sustainable management of tuna fisheries, and robust information is essential to ensure future sustainability. Climate and harvest affect tuna stocks, populations of non-target, dependent species and the ecosystem. To provide relevant advice we need an improved understanding of oceanic ecosystems and better data to parameterise the models that forecast the impacts of climate change. Currently ocean-wide data collection in the Pacific Ocean is primarily restricted to oceanographic data. However, the fisheries observer programs that operate in the region offer an opportunity to collect the additional information on the mid and upper trophic levels of the ecosystem that is necessary to complement this physical data, including time-series of distribution, abundance, size, composition and biological information on target and non-target species and mid trophic level organisms. These observer programs are in their infancy, with limited temporal and spatial distribution but recent international and national policy decisions have been made to expand their coverage. We identify a number of actions to initiate this monitoring including: consolidating collaborations to ensure the use of best quality data; developing consistency between sub-regional observer programmes to ensure that they meet the objectives of ecosystem monitoring; interrogating of existing time series to determine the most appropriate spatial template for monitoring; and exploring existing ecosystem models to identify suitable indicators of ecosystem status and change. The information obtained should improve capacity to develop fisheries management policies that are resilient and can be adapted to climate change. Content Type Journal Article Pages 1-15 DOI 10.1007/s10584-012-0598-y Authors Simon J. Nicol, Secretariat of the Pacific Community, BP D5, 98848 Noumea, New Caledonia Valerie Allain, Secretariat of the Pacific Community, BP D5, 98848 Noumea, New Caledonia Graham M. Pilling, Secretariat of the Pacific Community, BP D5, 98848 Noumea, New Caledonia Jeff Polovina, National Marine Fisheries Service, 2570 Dole Street, Honolulu, HI 96822, USA Marta Coll, Institut de Ciències del Mar, Passeig Maritim de la Barceloneta, 37-49, 08003 Barcelona, Spain Johann Bell, Secretariat of the Pacific Community, BP D5, 98848 Noumea, New Caledonia Paul Dalzell, Western Pacific Regional Fisheries Management Council, 1164 Bishop Street, Honolulu, HI 96813, USA Peter Sharples, Secretariat of the Pacific Community, BP D5, 98848 Noumea, New Caledonia Robert Olson, Inter-American Tropical Tuna Commission, 8604 La Jolla Shores Drive, La Jolla, CA 92037-1508, USA Shane Griffiths, Commonwealth Scientific and Industrial Research Organisation, 41 Boggo Road, Dutton Park, QLD 4102, Australia Jeffrey M. Dambacher, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1538, Hobart, TAS 7001, Australia Jock Young, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1538, Hobart, TAS 7001, Australia Antony Lewis, Secretariat of the Pacific Community, BP D5, 98848 Noumea, New Caledonia John Hampton, Secretariat of the Pacific Community, BP D5, 98848 Noumea, New Caledonia Jesus Jurado Molina, Secretariat of the Pacific Community, BP D5, 98848 Noumea, New Caledonia Simon Hoyle, Secretariat of the Pacific Community, BP D5, 98848 Noumea, New Caledonia Karine Briand, Secretariat of the Pacific Community, BP D5, 98848 Noumea, New Caledonia Nic Bax, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1538, Hobart, TAS 7001, Australia Patrick Lehodey, CLS, Space Oceanography Division, 8-10 rue Hermès, 31520 Ramonville, Saint-Agne, France Peter Williams, Secretariat of the Pacific Community, BP D5, 98848 Noumea, New Caledonia Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    The four species of tuna that underpin oceanic fisheries in the tropical Pacific (skipjack, yellowfin, bigeye and albacore tuna) deliver great economic and social benefits to Pacific Island countries and territories (PICTs). Domestic tuna fleets and local fish processing operations contribute 3–20 % to gross domestic product in four PICTs and licence fees from foreign fleets provide an average of 3–40 % of government revenue for seven PICTs. More than 12,000 people are employed in tuna processing facilities and on tuna fishing vessels. Fish is a cornerstone of food security for many PICTs and provides 50–90 % of dietary animal protein in rural areas. Several PICTs have plans to (1) increase the benefits they receive from oceanic fisheries by increasing the amount of tuna processed locally, and (2) allocate more tuna for the food security of their rapidly growing populations. The projected effects of climate change on the distribution of tuna in the tropical Pacific Ocean, due to increases in sea surface temperature, changes in velocity of major currents and decreases in nutrient supply to the photic zone from greater stratification, are likely to affect these plans. PICTs in the east of the region with a high dependence on licence fees for government revenue are expected to receive more revenue as tuna catches increase in their exclusive economic zones. On the other hand, countries in the west may encounter problems securing enough fish for their canneries as tuna are redistributed progressively to the east. Changes in the distribution of tuna will also affect the proportions of national tuna catches required for food security. We present priority adaptations to reduce the threats to oceanic fisheries posed by climate change and to capitalise on opportunities. Content Type Journal Article Pages 1-14 DOI 10.1007/s10584-012-0606-2 Authors Johann D. Bell, Secretariat of the Pacific Community, Noumea, New Caledonia Chris Reid, Forum Fisheries Agency, Honiara, Solomon Islands Michael J. Batty, Secretariat of the Pacific Community, Noumea, New Caledonia Patrick Lehodey, Collecte Localisation Satellites, Ramonville, France Len Rodwell, Forum Fisheries Agency, Honiara, Solomon Islands Alistair J. Hobday, Climate Adaptation Flagship, CSIRO Marine and Atmospheric Research, Hobart, TAS, Australia Johanna E. Johnson, C2O Consulting and Southern Cross University, Coffs Harbour, NSW, Australia Andreas Demmke, Secretariat of the Pacific Community, Noumea, New Caledonia Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Knowledge of cloud properties and their vertical structure is important for meteorological studies due to their impact on both the Earth’s radiation budget and adiabatic heating within the atmosphere. The objective of this study is to evaluate bulk cloud properties and vertical distribution simulated by the US National Oceanic and Atmospheric Administration National Centers for Environmental Prediction Global Forecast System (GFS) using three global satellite products. Cloud variables evaluated include the occurrence and fraction of clouds in up to three layers, cloud optical depth, liquid water path, and ice water path. Cloud vertical structure data are retrieved from both active (CloudSat/CALIPSO) and passive sensors and are subsequently compared with GFS model results. In general, the GFS model captures the spatial patterns of hydrometeors reasonably well and follows the general features seen in satellite measurements, but large discrepancies exist in low-level cloud properties. More boundary layer clouds over the interior continents were generated by the GFS model whereas satellite retrievals showed more low-level clouds over oceans. Although the frequencies of global multi-layer clouds from observations are similar to those from the model, latitudinal variations show discrepancies in terms of structure and pattern. The modeled cloud optical depth over storm track region and subtropical region is less than that from the passive sensor and is overestimated for deep convective clouds. The distributions of ice water path (IWP) agree better with satellite observations than do liquid water path (LWP) distributions. Discrepancies in LWP/IWP distributions between observations and the model are attributed to differences in cloud water mixing ratio and mean relative humidity fields, which are major control variables determining the formation of clouds. Content Type Journal Article Pages 1-19 DOI 10.1007/s00382-012-1430-0 Authors Hyelim Yoo, Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD 20740, USA Zhanqing Li, Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD 20740, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description: Safeguarding the future of oceanic fisheries under climate change depends on timely preparation Content Type Journal Article Pages 1-6 DOI 10.1007/s10584-012-0609-z Authors Jim Salinger, Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA Alistair J. Hobday, Climate Adaptation Flagship, CSIRO Marine and Atmospheric Research, Hobart, Tasmania 7001, Australia Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    The Atlantic subpolar gyre (SPG) is one of the main drivers of decadal climate variability in the North Atlantic. Here we analyze its dynamics in pre-industrial control simulations of 19 different comprehensive coupled climate models. The analysis is based on a recently proposed description of the SPG dynamics that found the circulation to be potentially bistable due to a positive feedback mechanism including salt transport and enhanced deep convection in the SPG center. We employ a statistical method to identify multiple equilibria in time series that are subject to strong noise and analyze composite fields to assess whether the bistability results from the hypothesized feedback mechanism. Because noise dominates the time series in most models, multiple circulation modes can unambiguously be detected in only six models. Four of these six models confirm that the intensification is caused by the positive feedback mechanism. Content Type Journal Article Pages 1-15 DOI 10.1007/s00382-012-1525-7 Authors Andreas Born, Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland Thomas F. Stocker, Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland Christoph C. Raible, Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland Anders Levermann, Potsdam Institute for Climate Impact Research, Potsdam, Germany Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Recent studies suggested that tropical cyclones (TCs) contribute significantly to the meridional oceanic heat transport by injecting heat into the subsurface through mixing. Here, we estimate the long-term oceanic impact of TCs by inserting realistic wind vortices along observed TCs tracks in a 1/2° resolution ocean general circulation model over the 1978–2007 period. Warming of TCs’ cold wakes results in a positive heat flux into the ocean (oceanic heat uptake; OHU) of ~480 TW, consistent with most recent estimates. However, ~2/5 of this OHU only compensates the heat extraction by the TCs winds during their passage. Another ~2/5 of this OHU is injected in the seasonal thermocline and hence released back to the atmosphere during the following winter. Because of zonal compensations and equatorward transport, only one-tenth of the OHU is actually exported poleward (46 TW), resulting in a marginal maximum contribution of TCs to the poleward ocean heat transport. Other usually neglected TC-related processes however impact the ocean mean state. The residual Ekman pumping associated with TCs results in a sea-level drop (rise) in the core (northern and southern flanks) of TC-basins that expand westward into the whole basin as a result of planetary wave propagation. More importantly, TC-induced mixing and air-sea fluxes cool the surface in TC-basins during summer, while the re-emergence of subsurface warm anomalies warms it during winter. This leads to a ~10 % reduction of the sea surface temperature seasonal cycle within TCs basins, which may impact the climate system. Content Type Journal Article Pages 1-20 DOI 10.1007/s00382-012-1556-0 Authors Emmanuel M. Vincent, LOCEAN-IPSL, IRD/CNRS/UPMC/MNHN, tour 45-55 4e, 4, place Jussieu, 75252 Paris Cedex 5, France Gurvan Madec, LOCEAN-IPSL, IRD/CNRS/UPMC/MNHN, tour 45-55 4e, 4, place Jussieu, 75252 Paris Cedex 5, France Matthieu Lengaigne, LOCEAN-IPSL, IRD/CNRS/UPMC/MNHN, tour 45-55 4e, 4, place Jussieu, 75252 Paris Cedex 5, France Jérôme Vialard, LOCEAN-IPSL, IRD/CNRS/UPMC/MNHN, tour 45-55 4e, 4, place Jussieu, 75252 Paris Cedex 5, France Ariane Koch-Larrouy, LEGOS, IRD/CNRS/UPS, Toulouse, France Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The characteristic features of Indian summer monsoon (ISM) and monsoon intraseasonal oscillations (MISO) are analyzed in the 25 year simulation by the superparameterized Community Climate System Model (SP-CCSM). The observations indicate the low frequency oscillation with a period of 30–60 day to have the highest power with a dominant northward propagation, while the faster mode of MISO with a period of 10–20 day shows a stationary pattern with no northward propagation. SP-CCSM simulates two dominant quasi-periodic oscillations with periods 15–30 day and 40–70 day indicating a systematic low frequency bias in simulating the observed modes. Further, contrary to the observation, the SP-CCSM 15–30 day mode has a significant northward propagation; while the 40–70 day mode does not show prominent northward propagation. The inability of the SP-CCSM to reproduce the observed modes correctly is shown to be linked with inability of the cloud resolving model (CRM) to reproduce the characteristic heating associated with the barotropic and baroclinic vertical structures of the high-frequency and the low-frequency modes. It appears that the superparameterization in the General Circulation Model (GCM) certainly improves seasonal mean model bias significantly. There is a need to improve the CRM through which the barotropic and baroclinic modes are simulated with proper space and time distribution. Content Type Journal Article Pages 1-11 DOI 10.1007/s00382-012-1563-1 Authors Bidyut B. Goswami, Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, Pune, 411008 India P. Mukhopadhyay, Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, Pune, 411008 India Marat Khairoutdinov, School of Marine and Atmospheric Science, New York University, Stony Brook, NY, USA B. N. Goswami, Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pashan, Pune, 411008 India Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The boreal summer intraseasonal oscillation (BSISO) of the Asian summer monsoon (ASM) is one of the most prominent sources of short-term climate variability in the global monsoon system. Compared with the related Madden-Julian Oscillation (MJO) it is more complex in nature, with prominent northward propagation and variability extending much further from the equator. In order to facilitate detection, monitoring and prediction of the BSISO we suggest two real-time indices: BSISO1 and BSISO2, based on multivariate empirical orthogonal function (MV-EOF) analysis of daily anomalies of outgoing longwave radiation (OLR) and zonal wind at 850 hPa (U850) in the region 10°S–40°N, 40°–160°E, for the extended boreal summer (May–October) season over the 30-year period 1981–2010. BSISO1 is defined by the first two principal components (PCs) of the MV-EOF analysis, which together represent the canonical northward propagating variability that often occurs in conjunction with the eastward MJO with quasi-oscillating periods of 30–60 days. BSISO2 is defined by the third and fourth PCs, which together mainly capture the northward/northwestward propagating variability with periods of 10–30 days during primarily the pre-monsoon and monsoon-onset season. The BSISO1 circulation cells are more Rossby wave like with a northwest to southeast slope, whereas the circulation associated with BSISO2 is more elongated and front-like with a southwest to northeast slope. BSISO2 is shown to modulate the timing of the onset of Indian and South China Sea monsoons. Together, the two BSISO indices are capable of describing a large fraction of the total intraseasonal variability in the ASM region, and better represent the northward and northwestward propagation than the real-time multivariate MJO (RMM) index of Wheeler and Hendon. Content Type Journal Article Pages 1-17 DOI 10.1007/s00382-012-1544-4 Authors June-Yi Lee, International Pacific Research Center, University of Hawaii, POST Bldg, Room 409A, 1680 East–West Road, Honolulu, HI 96822, USA Bin Wang, International Pacific Research Center, University of Hawaii, POST Bldg, Room 409A, 1680 East–West Road, Honolulu, HI 96822, USA Matthew C. Wheeler, Centre for Australia Weather and Climate Research (CAWCR), Bureau of Meteorology, Melbourne, Australia Xiouhua Fu, International Pacific Research Center, University of Hawaii, POST Bldg, Room 409A, 1680 East–West Road, Honolulu, HI 96822, USA Duane E. Waliser, JIFRESSE, University of California, Los Angeles, USA In-Sik Kang, Seoul National University, Seoul, Korea Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Numerical models of climate have great difficulties with the simulation of marine low clouds in the subtropical Pacific and Atlantic Oceans. It has been especially difficult to reproduce the observed geographical distributions of the different cloud regimes in those regions. The present study discusses mechanisms proposed in previous works for changing one regime into another. One criterion is based on the theory of stratocumulus destruction through cloud top entrainment instability due to buoyancy reversal—situations in which the mixture of two air parcels becomes denser than either of the original parcels due to evaporation of cloud water. Another criterion is based on the existence of decoupling in the boundary layer. When decoupled, the stratocumulus regime changes to another in which these clouds can still exist together with cumulus. In a LES study, the authors have suggested that a combination of those two criteria can be used to diagnose whether, at a location, the cloud regime corresponds to a well-mixed stratocumulus regime, a shallow cumulus regime, or to a transitional regime where the boundary layer is decoupled. The concept is tested in the framework of an atmospheric general circulation model (GCM). It is found that several outstanding features of disagreement between simulation and observation can be interpreted as misrepresentations of the cloud regimes by the GCM. A novel criterion for switching among regimes is proposed to alleviate the effects of these misrepresentations. Content Type Journal Article Pages 1-15 DOI 10.1007/s00382-012-1342-z Authors Heng Xiao, Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA 90095, USA Chien-Ming Wu, Department of Atmospheric Sciences, National Taiwan University, Taipei, 106 Taiwan C. Roberto Mechoso, Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA 90095, USA Hsi-Yen Ma, Program for Climate Model Diagnosis and Intercomparison, Lawrence Livermore National Laboratory, Livermore, CA, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Land-use, land-use change and forestry (LULUCF) activities will play an important role in global climate change mitigation. Many carbon schemes require the delivery of both climate and rural development benefits by mitigation activities conducted in developing countries. Agroforestry is a LULUCF activity that is gaining attention because of its potential to deliver climate benefits as well as rural development benefits to smallholders. There is hope that agroforestry can deliver co-benefits for climate and development; however experience with early projects suggests co-benefits are difficult to achieve in practice. We review the literature on agroforestry, participatory rural development, tree-based carbon projects and co-benefit carbon projects to look at how recommended project characteristics align when trying to generate different types of benefits. We conclude that there is considerable tension inherent in designing co-benefit smallholder agroforestry projects. We suggest that designing projects to seek ancillary benefits rather than co-benefits may help to reduce this tension. Content Type Journal Article Pages 1-17 DOI 10.1007/s10584-012-0456-y Authors Emily K. Anderson, Institute for Resources, Environment and Sustainability, The University of British Columbia, 411-2202 Main Mall, Vancouver, BC, Canada V6T 1Z4 Hisham Zerriffi, Liu Institute for Global Issues, The University of British Columbia, 101-6476 NW Marine Dr, Vancouver, BC, Canada V6T 1Z2 Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Assessments conducted by the Intergovernmental Panel on Climate Change (IPCC) are significant undertakings that require input from experts and practitioners in multiple scientific disciplines, integrating local to international information across spatial and temporal scales. An IPCC report is a unique collaboration between the scientific community and policymakers, with governments (through their Focal Points) providing guidance and input to the scientists conducting an assessment at several stages during the process. This commentary reviews the IPCC mandate and process; summarizes key themes to be addressed in the Working Group II contribution to the 5th assessment report; discusses challenges for the WGII report when assessing qualitative literature, incorporating local knowledge, and identifying particularly vulnerable groups; and touches on the expertise and commitment of the WGII authors. Active engagement of the wider scientific community in IPCC assessments through publication and review will enhance their relevance to decision- and policy-makers. Content Type Journal Article Category Springboard Commentary Pages 1-10 DOI 10.1007/s10584-012-0442-4 Authors Kristie L. Ebi, Carnegie Institution for Science, 260 Panama Street, Stanford, CA 94305, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Tree-ring records are a valuable source of information for understanding long-term, regional-scale drought changes. In this study, a tree ring width chronology spanning the last 330 years (A.D. 1681–2010) is developed for the northern fringe of the Asian summer monsoon in north central China based on tree ring widths of the Chinese pine (Pinus tabulaeformis) at three sites in the Hasi Mountain (HSM). An annual (running from the previous August to the present July) Palmer Drought Severity Index (PDSI) series is reconstructed for the period A.D. 1698 to 2010 using a linear regression model. This reconstruction accounts for 49 % of the actual PDSI variance during the calibration period (A.D.1951–2005). During the last past 330 years, the year 1759 drought was the most severe and the 1926–1932 drought was the most long-lasting. These drought episodes resulted in huge economic losses and severe famine. Similar periods of drought are also found in the Great Bend of the Yellow River region, northeastern Tibetan Plateau and northern China. Our drought reconstruction is consistent with the dry-wet index derived from historical documents for the Great Bend of the Yellow River region for the last three centuries, revealing that our annual PDSI reconstruction reflects broad-scale climate anomalies and represents drought variations in the northern fringe of the Asian summer monsoon. The PDSI reconstruction correlates significantly with sea surface temperature (SST) in the eastern equatorial Pacific Ocean and northern Indian Ocean at an annual timescale, implying that El Niño-Southern Oscillation and the Indian monsoon might be influencing drought variability in the study area. Some extremely dry years of 1707, 1764, 1837, 1854, 1878, 1884, 1926 and 1932 coincided with major El Niño events in historical times. The decadal-scale variability is linked to Pacific Decadal Oscillation (PDO) and SST variations in the Atlantic Ocean. The observed recent tree growth reduction is unusual when viewed from a long-term perspective. Content Type Journal Article Pages 1-18 DOI 10.1007/s10584-012-0440-6 Authors Shuyuan Kang, Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, 320 Donggang West Rd., Lanzhou, Gansu Province, China 730000 Bao Yang, Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, 320 Donggang West Rd., Lanzhou, Gansu Province, China 730000 Chun Qin, Key Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, 320 Donggang West Rd., Lanzhou, Gansu Province, China 730000 Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Decadal climate predictability is examined in hindcast experiments by a multi-model ensemble using three versions of the coupled atmosphere-ocean model MIROC. In these hindcast experiments, initial conditions are obtained from an anomaly assimilation procedure using the observed oceanic temperature and salinity with prescribed natural and anthropogenic forcings on the basis of the historical data and future emission scenarios in the Intergovernmental Panel of Climate Change. Results of the multi-model ensemble in our hindcast experiments show that predictability of surface air temperature (SAT) anomalies on decadal timescales mostly originates from externally forced variability. Although the predictable component of internally generated variability has considerably smaller SAT variance than that of externally forced variability, ocean subsurface temperature variability has predictive skills over almost a decade, particularly in the North Pacific and the North Atlantic where dominant signals associated with Pacific decadal oscillation (PDO) and the Atlantic multidecadal oscillation (AMO) are observed. Initialization enhances the predictive skills of AMO and PDO indices and slightly improves those of global mean temperature anomalies. Improvement of these predictive skills in the multi-model ensemble is higher than that in a single-model ensemble. Content Type Journal Article Pages 1-22 DOI 10.1007/s00382-012-1351-y Authors Yoshimitsu Chikamoto, Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba, 277-8568 Japan Masahide Kimoto, Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba, 277-8568 Japan Masayoshi Ishii, Meteorological Research Institute, Tsukuba, Japan Takashi Mochizuki, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan Takashi T. Sakamoto, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan Hiroaki Tatebe, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan Yoshiki Komuro, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan Masahiro Watanabe, Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba, 277-8568 Japan Toru Nozawa, National Institute for Environmental Studies, Tsukuba, Japan Hideo Shiogama, National Institute for Environmental Studies, Tsukuba, Japan Masato Mori, Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba, 277-8568 Japan Sayaka Yasunaka, National Institute for Environmental Studies, Tsukuba, Japan Yukiko Imada, Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Tokyo, Japan Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Numerical experiments with different idealized land and mountain distributions are carried out to study the formation of the Asian monsoon and related coupling processes. Results demonstrate that when there is only extratropical continent located between 0 and 120°E and between 20/30°N and the North Pole, a rather weak monsoon rainband appears along the southern border of the continent, coexisting with an intense intertropical convergence zone (ITCZ). The continuous ITCZ surrounds the whole globe, prohibits the development of near-surface cross-equatorial flow, and collects water vapor from tropical oceans, resulting in very weak monsoon rainfall. When tropical lands are integrated, the ITCZ over the longitude domain where the extratropical continent exists disappears as a consequence of the development of a strong surface cross-equatorial flow from the winter hemisphere to the summer hemisphere. In addition, an intense interaction between the two hemispheres develops, tropical water vapor is transported to the subtropics by the enhanced poleward flow, and a prototype of the Asian monsoon appears. The Tibetan Plateau acts to enhance the coupling between the lower and upper tropospheric circulations and between the subtropical and tropical monsoon circulations, resulting in an intensification of the East Asian summer monsoon and a weakening of the South Asian summer monsoon. Linking the Iranian Plateau to the Tibetan Plateau substantially reduces the precipitation over Africa and increases the precipitation over the Arabian Sea and the northern Indian subcontinent, effectively contributing to the development of the South Asian summer monsoon. Content Type Journal Article Pages 1-13 DOI 10.1007/s00382-012-1334-z Authors Guoxiong Wu, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China Yimin Liu, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China Buwen Dong, Department of Meteorology, National Centre for Atmospheric Science, University of Reading, Reading, UK Xiaoyun Liang, National Climate Center, China Meteorological Administration, Beijing, China Anmin Duan, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China Qing Bao, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China Jingjing Yu, National Meteorological Information Center, China Meteorological Administration, Beijing, China Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The spring asymmetric mode over the Tropical Indian Ocean (TIO) is characterized by contrasting patterns of rainfall and surface wind anomalies north and south of Equator. The asymmetric pattern in rainfall has evolved as a leading mode of variability in the TIO and is strongly correlated with El Niño-Southern Oscillation (ENSO) and positive Indian Ocean Dipole (IOD). The evolution of the asymmetric pattern in rainfall and surface wind during pure El Niño/IOD and co-occurrence years are examined in the twentieth century reanalysis for the period of 1871–2008 and atmospheric general circulation model (AGCM) simulations. The study revealed that spring asymmetric mode is well developed when El Niño co-occurred with IOD (positive) and is driven by the associated meridional gradients in sea surface temperature (SST) and sea level pressure (SLP). The pure El Niño composites are characterized by homogeneous (spatially) SST anomalies (positive) and weaker SLP gradients and convection, leading to weak asymmetric mode. The asymmetric mode is absent in the pure IOD (positive) composites due to the persistence of east west SST gradient for a longer duration than the co-occurrence years. The meridional gradient in SST anomalies over the TIO associated with the ENSO-IOD forcing is therefore crucial in developing/strengthening the spring asymmetric mode. The northwest Pacific anticyclonic circulation further strengthen the asymmetric mode in surface winds by inducing northeasterlies in the north Indian Ocean during pure El Niño and co-occurrence years. The simulations based on AGCM, forced by observed SSTs during the period of 1871–2000 supported the findings. The analysis of available station and ship track data further strengthens our results. Content Type Journal Article Pages 1-15 DOI 10.1007/s00382-012-1340-1 Authors Soumi Chakravorty, Indian Institute of Tropical Meteorology, Pune, 411008 India J. S. Chowdary, Indian Institute of Tropical Meteorology, Pune, 411008 India C. Gnanaseelan, Indian Institute of Tropical Meteorology, Pune, 411008 India Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    The Indian summer monsoon rainfall (ISMR) over the Western Ghats (WG) and the Bay of Bengal (BoB) is marked by the intraseasonal oscillations (ISOs) with preferred 10–20-day and 30–50-day bands. On the basis of pentad Climate Prediction Center Merged Analysis Precipitation and daily sea level pressure and winds at 850 hPa derived from European Center for Medium-range Weather Forecast reanalysis, we present the structure and evolution of the ISOs linked to the ISMR variations over the WG and the BoB and the associated anomalies of the atmospheric circulation using the approaches of wavelet analysis, bandpass filtering and composite analysis. This study reveals that the activities of both the intertropical convergence zone (ITCZ) and the western Pacific subtropical high (WPSH) contribute strongly to the structure and propagation of the ISOs on intraseasonal time scales. Northward development and propagation of the ITCZ plays a critical role in the northward-propagating ISOs, but not in the westward-propagating BoB 10–20-day ISOs. The latter ISOs may be linked, instead, to the activity of synoptic-scale weather systems to the east over the western tropical Pacific. The enhanced ITCZ in the tropical Indian Ocean plays a strong role in the sudden strengthening of the WPSH during the transition from the break to active phase of the 30–50-day ISOs. We find that the strong WPSH in the Asian summer monsoon season, with generally northward advance and eastward withdrawal, promotes the formation of a northwest to southeast tilted anomalous rainfall belt over the East Asian tropical summer monsoon region and the western tropical Pacific in the 30–50-day low-frequency band. Positive (Negative) elongated rainfall anomalies with an unbroken northwest-southeast tilt, strong easterly (westerly) anomalies in the tropical Pacific, and northward advance and eastward movement of strong (weak) WPSH are favorable for maintaining the eastward propagation of the 30–50-day ISOs in the Pacific. Daily high-resolution sea surface temperature obtained from the National Oceanic and Atmospheric Administration is used to explain the propagation features of the 10–20-day ISOs in the Indian Ocean. Content Type Journal Article Pages 1-18 DOI 10.1007/s00382-012-1352-x Authors S. Ma, Institut Català de Ciències del Clima (IC3), C/Doctor Trueta 203, 08005 Barcelona, Catalunya, Spain X. Rodó, Institut Català de Ciències del Clima (IC3), C/Doctor Trueta 203, 08005 Barcelona, Catalunya, Spain Y. Song, School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA B. A. Cash, Center for Ocean-Land–Atmosphere Studies, Calverton, MD, USA Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Attack of decay fungi on wood-based material depends primarily on the natural durability of wood, the local climatic conditions, and the likely climatic change. This study investigates the vulnerability of wood and structural timber in ground contact to decay fungi under high and medium emissions scenarios specified by the Intergovernmental Panel on Climate Change, and a future scenario in which the global emissions have been limited to 550 ppm through a range of successful intervention schemes. Nine general circulation models are applied to project the local climates of Brisbane, Sydney, and Melbourne in Australia. It was found that, under the three emissions scenarios, the median decay rate of wood by 2080, relative to that in 2010, could increase up to 10 % in Brisbane and Sydney, but could decrease by 12 % in Melbourne. For timber of less durable wood species 50 years after installation, the residual strength under climate change could be almost 25 % less than that without climate change. The coefficients of variation (COVs) of decay rate of wood are in the vicinity of 1.0 regardless of wood species. For residual strength of timber pole after 50 years of installation, the COVs range from 0.2 to 1.1, depending on the natural durability of timber and the site location. The high COVs due to the variability of natural durability of wood and of climate change, in combination with the likely changes in median residual strength of structural elements, will cause significant structural reliability issues of wood construction and need to be addressed in engineering design codes. Content Type Journal Article Pages 1-18 DOI 10.1007/s10584-012-0454-0 Authors Chi-hsiang Wang, CSIRO Climate Adaptation Flagship and CSIRO Ecosystem Sciences, PO Box 56, 37 Graham Road, Highett, Victoria 3190, Australia Xiaoming Wang, CSIRO Climate Adaptation Flagship and CSIRO Ecosystem Sciences, PO Box 56, 37 Graham Road, Highett, Victoria 3190, Australia Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Under the background of a warming climate, regional climate responses may be different from place to place. How cold extreme events in China respond is still an open question. This study investigates responses of coldwave frequency (CWF) in China from observation and modeling perspectives. Observational evidences show that CWF significantly reduces across China during the warm period (1978–2009) in comparison with that during the cold period (1957–1977), concurrent with extreme value centers located in northern China during 1957–1977 and southern China during 1978–2009. The empirical orthogonal function (EOF) leading mode of CWF in the cold period is also dominant by an extreme value center prevailing over northern China, while the center exhibits a southward shift in the warm period. A seven-member multi-model ensemble (MME) from coupled model intercomparison project#3 (CMIP3) shows that southern China tends to experience more coldwaves than northern China in the twenty first century (2045–2064 and 2080–2099) under the global warming A1B forcing (with atmospheric CO 2 concentration of 720 ppm). This feature can also be seen in the leading EOF mode of MME. These results indicate that the primary response of CWF to a warming climate may be the southward shift of the maximum loading center. The enhanced western Pacific Subtropical High and weakened Siberian High during 1978–2009 may result in anomalous southerlies which bring warm and wet air to southern China. Meanwhile cold and dry air is transported from the north via a “northwest pathway” to southern China. Under the joint action of these two air masses, coldwaves may easily generate in southern China as observed in recent extreme cold events in this region. Content Type Journal Article Pages 1-10 DOI 10.1007/s00382-012-1354-8 Authors Tingting Ma, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing, China Zhiwei Wu, Meteorological Research Division, Environment Canada, Dorval, QC H9P 1J3, Canada Zhihong Jiang, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing, China Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575

Description:    Climate change could have major implications for the global tourism industry if changing environmental conditions alter the attractiveness of holiday destinations. Countries with economies dependent on tourism and with tourism industries reliant on vulnerable natural resources are likely to be particularly at risk. We investigate the implications that climate-induced variations in Atlantic hurricane activity may have for the tourism-dependent Caribbean island of Anguilla. Three hundred tourists completed standardised questionnaires and participated in a choice experiment to determine the influence hurricane risk has on their risk perceptions and decisions regarding holiday preferences. The hurricane season had been considered by 40 % of respondents when making their holiday choice, and the beaches, climate and tranquility of the island were more important than coral reef-based recreational activities in determining holiday destination choice. Choice models demonstrated that respondents were significantly less likely to choose holiday options where hurricane risk is perceived to increase, and significantly more likely to choose options that offered financial compensation for increased risk. However, these choices and decisions varied among demographic groups, with older visitors, Americans, and people who prioritize beach-based activities tending to be most concerned about hurricanes. These groups comprise a significant component of the island’s current clientele, suggesting that perceived increases in hurricane risk may have important implications for the tourism economy of Anguilla and similar destinations. Improved protection of key environmental features (e.g. beaches) may be necessary to enhance resilience to potential future climate impacts. Content Type Journal Article Pages 1-24 DOI 10.1007/s10584-012-0433-5 Authors Johanna Forster, School of Marine Science and Technology, Newcastle University, Ridley Building 2, Newcastle upon Tyne, NE1 7RU UK Peter W. Schuhmann, Department of Economics and Finance, University of North Carolina at Wilmington, Wilmington, NC 28403-3297, USA Iain R. Lake, School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK Andrew R. Watkinson, School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK Jennifer A. Gill, School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ UK Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description: Erratum to: On climate change and cultural geography: farming on the Lizard Peninsula, Cornwall, UK Content Type Journal Article Category Erratum Pages 1-1 DOI 10.1007/s10584-012-0457-x Authors Hilary Geoghegan, Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK Catherine Leyshon, Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    Climate data suggest greater warming over the Arctic than lower latitudes, and the most abundant direct source of black carbon and other climate-relevant pollutants over the Arctic is cross-polar flights by international aviation. A relevant question is whether rerouting cross-polar flights to circumnavigate the Arctic Circle reduces or enhances such warming. To study this issue, a model accounting for subgrid exhaust plumes from each individual commercial flight worldwide was used with 2006 global aircraft emission inventories that treated cross-polar flights and flights rerouted around the Arctic Circle (66.56083 °N), respectively. Rerouting increased fuel use by 0.056 % in the global average, mostly right outside the Arctic Circle, but most of the associated black carbon and other emissions were removed faster because they were now over latitudes of greater precipitation and lesser stability. Rerouting also reduced fuel use and emissions within the Arctic Circle by 83 % and delayed pollutant transport to the Arctic. The Arctic reduction in pollutants, particularly of black carbon, decreased Arctic and global temperature and increased Arctic sea ice over 22 years. Although the slight increase in total CO 2 emissions due to rerouting may dampen the benefit of rerouting over more decades, rerouting or even partial rerouting (allowing cross-polar flights during polar night only) may delay the elimination of Arctic sea ice, which will otherwise likely occur within the next 2–3 decades due to global warming in general. Rerouting may increase worldwide fuel plus operational costs by only ~$99 million/yr, 47–55 times less than an estimated 2025 U.S.-alone cost savings due to the global warming reduction from rerouting. Content Type Journal Article Pages 1-16 DOI 10.1007/s10584-012-0462-0 Authors Mark Z. Jacobson, Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA Jordan T. Wilkerson, Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA Sathya Balasubramanian, Volpe National Transportation Systems Center, Cambridge, MA, USA Wayne W. Cooper, MITRE Corporation Center for Advanced Aviation System Development (CAASD), McLean, VA, USA Nina Mohleji, MITRE Corporation Center for Advanced Aviation System Development (CAASD), McLean, VA, USA Journal Climatic Change Online ISSN 1573-1480 Print ISSN 0165-0009

Description:    The interannual variation of precipitation in the southern part of Iran and its link with the large-scale climate modes are examined using monthly data from 183 meteorological stations during 1974–2005. The majority of precipitation occurs during the rainy season from October to May. The interannual variation in fall and early winter during the first part of the rainy season shows apparently a significant positive correlation with the Indian Ocean Dipole (IOD) and El Niño-Southern Oscillation (ENSO). However, a partial correlation analysis used to extract the respective influence of IOD and ENSO shows a significant positive correlation only with the IOD and not with ENSO. The southeasterly moisture flux anomaly over the Arabian Sea turns anti-cyclonically and transport more moisture to the southern part of Iran from the Arabian Sea, the Red Sea, and the Persian Gulf during the positive IOD. On the other hand, the moisture flux has northerly anomaly over Iran during the negative IOD, which results in reduced moisture supply from the south. During the latter part of the rainy season in late winter and spring, the interannual variation of precipitation is more strongly influenced by modes of variability over the Mediterranean Sea. The induced large-scale atmospheric circulation anomaly controls moisture supply from the Red Sea and the Persian Gulf. Content Type Journal Article Pages 1-13 DOI 10.1007/s00382-012-1357-5 Authors Farnaz Pourasghar, Department of Physical Geography, Faculty of Humanities and Social Science, The University of Tabriz, Tabriz, Iran Tomoki Tozuka, Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan Saeed Jahanbakhsh, Department of Physical Geography, Faculty of Humanities and Social Science, The University of Tabriz, Tabriz, Iran Behrooz Sari Sarraf, Department of Physical Geography, Faculty of Humanities and Social Science, The University of Tabriz, Tabriz, Iran Hooshang Ghaemi, Iran Meteorological Organization, Tehran, Iran Toshio Yamagata, Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan Journal Climate Dynamics Online ISSN 1432-0894 Print ISSN 0930-7575