ALBERT

Description: Intercomparison of two meteorological limited area models for quantitative precipitation forecast verification Natural Hazards and Earth System Science, 12, 591-606, 2012 Author(s): E. Oberto, M. Milelli, F. Pasi, and B. Gozzini The demand for verification of numerical models is still very high, especially for what concerns the operational Quantitative Precipitation Forecast (QPF) used, among others, for evaluating the issuing of warnings to the population. In this study, a comparative verification of the QPF, predicted by two operational Limited Area Models (LAMs) for the Italian territory is presented: COSMO-I7 (developed in the framework of the COSMO Consortium) and WRF-NMM (developed at NOAA-NCEP). The observational dataset is the precipitation recorded by the high-resolution non-GTS rain gauges network of the National Civil Protection Department (NCPD) over two years (2007–2008). Observed and forecasted precipitation have been treated as areal quantity (areal average of the values accumulated in 6 and 24 h periods) over the 102 "warning areas", defined by the NCPD both for administrative and hydrological purposes. Statistics are presented through a series of conventional indices (BIAS, POD and POFD) and, in addition, the Extreme Dependency Score (EDS) and the Base Rate (BS or 1-BS) have been used for keeping into account the vanishing of the indices as the events become rare. Results for long-period verification (the whole 2 yr) with increasing thresholds, seasonal trend (3 months period), diurnal error cycle and error maps, are presented. Results indicate that WRF has a general tendency of QPF overestimation for low thresholds and underestimation for higher ones, while COSMO-I7 tends to overestimate for all thresholds. Both models show a seasonal trend, with a bigger overestimation during summer and spring, while during autumn and winter the models tend to be more accurate.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 6 Sarah Cornell, Cat Downy ESS2010 was the first Open Science Conference of the international collaborative initiative AIMES, and was convened and organized by QUEST, the UK's directed research programme for Earth System science. The conference showcased advances in Earth system modelling, deploying observations and process understanding to develop more quantitative and predictive understanding of the interactions of the climate system, the biosphere and the anthroposphere. These tools extend understanding of the system dynamics of biogeochemical cycles, and give perspectives on the relationships between climate, ecosystems and human needs. As Earth system science is a global research endeavour, and its remit has important societal and policy implications, a recurrent theme in the conference was the responsibility of scientists working on knowledge integration in the global environmental change context.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 4 Ma Chun, Ju Mei-ting, Zhang Xiao-chun, Li Hong-yuan Analyses of energy consumption and carbon emissions in Tianjin are ways to understand the dynamics of developing cities in China. Using carbon emission calculation methodology recommended by IPCC, the amount of energy consumption and carbon emissions in Tianjin were calculated from 1995 to 2007. The results showed that the energy consumption structure in Tianjin relied on coal. Annual carbon emission was 26.37 million tons with growth of 4.48% per year; Sc (carbon emission per GDP) reduced year by year, and Se (carbon emission per energy consumption) decreased overall. We also proposed countermeasures to reduce carbon emissions from energy consumption.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 10, Part B Yanhong Yan, Zhining Jia, Yulin Yang The polytetrafluroethylene (PTFE) polymer-based nanocomposites filled with nanoscale lamellar structure expanded graphite (nano-EG) and reinforced with different nanoparticles, such as nano-Al 2 O 3 , nano-copper, nano-SiO 2 and nano-TiO 2 , were prepared by using cold briquetting and hot-press sintering technologies. The quasi-static tensile experiments and dynamic mechanical thermal analysis (DTMA) were carried out. The results showed that the mechanical properties of these nanocomposites stronger depend on the variety of nanoparticles. Stress-displacement and stress relaxation curves indicate that theses composites are typical viscoelastic materials. However, due to the addition of nano-EG and other nano-particles, some composites showed relatively brittle to some extent. These research findings are believed to be helpful for providing practical guide in harsh environments.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 11, Part C Liu Hongmin Crew's health and productivity is strongly affected by cabins’ thermal environment. This paper focuses on the numerical simulation of the indoor thermal environment in air-conditioned vessel cabins. The original airconditioning system of the cabin was analyzed. Three modified air-conditioning systems with different air-supply outlet locations and under-supply air-conditioning system were put forward for optimization. Air temperature, air velocity and PMV distribution were discussed under Airpak simulation. The results show that under-supply airconditioning system has good performance with little eddies and can contribute to energy saving. Indoor air temperature with under-supply air-conditioning system was 2∼4 lower than that °C with original air-conditioning system, leading to lower predicted mean vote (PMV).

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 8 Parvinder Singh Sandhu

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 10, Part C Xin Zhou, Ziru Lian, Jiangtao Wang, Liju Tan, Zhichao Zhao Estrogens (estrone, estradiol and estriol) and synthetic compound (ethynyl estradiol) in the water and sediment of Licun River-Jiaozhou Bay area in Qingdao were monitored. Estrogens in waters were concentrated using modified C- 18 SPE cartridges, and estrogens in sediments were extracted by liquid-solid extraction. Silane derivatives of the extracted and concentrated estrogens were analyzed by GC-MS. The concentration of estrogens ranged from ND (below the detection limit) to 180 ng/L in waters and ND to 10.8 colong/kg (dry weight) in sediment. The concentrations of estrogen in river water were higher than those in seawater during the monitoring periods. The distribution of estrogen concentration along Licun river suggested that estrogens were different with distance from the respective effluent sites. The highest concentrations were detected at station 5 which directly receives huge quantities of pollutants from adjacent rivers containing large amounts of farming and industrial wastewater.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 9 Jean-Christophe Lata, Sébastien Barot, Gérard Lacroix The International Congress “Ecological Engineering; from concepts to applications”, Paris, was held on 2-4 December, 2009 [3]. These three days were dedicated to the exploration of new breakthroughs in ecological engineering and reflections on the way to develop the field and ground it on sound ecological and conceptual bases

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 6 Cat Downy, Sarah Cornell

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 11, Part B Shuzhou Wang, Bo Meng Neural networks with good nonlinear mapping abilities can be applied to build simulation model of helicopter. But they have some difficulties such as hardness of selecting network structure, slow convergence speed, local minimum, and over-fitting. To avoid above problems, a modeling method for dynamic nonlinear system based on support vector machine was proposed. This method was applied to build simulation model of helicopter. Compared with neural network model, SVM model possess some advantages such as simple structure, fast convergence speed and high generalization ability.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 10, Part C Xu Shujian, Wang Tao The grain size records of loess-paleosol deposit in China are some of the most important terrestrial records of the Quaternary. It systematically carried out fieldwork on loess profile of Tuoji Island on Miaodao Islands and Changyi profile on the Laizhou Bay plain, analyzed grain size of 220 and 86 samples respectively. It shows the grain size of loess in Tuoji Island profile coarser than Changyi profile. The environment-sensitive size fractions of Tuoji Island and Changyi loess section respectively are 89.1-100.0colonm and 70.8-79.4colonm, by analyzing grain-size class vs. standard deviation values method. The changes of grain size characteristics of loess-paleosol recorded in different sections implicated the much plentiful materials in the Changyi profile on Laizhou Bay plain than Tuoji profile on Miaodao Islands.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 11, Part C Zhiming Fang, Xiaochun Li This paper presents a preliminary assessment of the potential for CO2 geological storage in Chongqing, China. Currently, there are about 116 large stationary CO2 point emission sources which emit 85.57 MtCO2/yr totally. These stationary sources are mainly belonged to four industries: cement, power plant, iron & steel and synthetic ammonia industries. In the three kinds of geological storage formations, namely, deep saline formations (DSFs), unmineable coalbeds and depleted gas fields, the total basin-scale theoretical storage capacities of CO2 reach 24.36 Gt, equivalent to about 285 times of the annual total CO2 emissions in Chongqing. The DSFs have the largest potential storage capacity accounting for 98% of the total storage capacities. The matching results between CO2 point emission sources and candidate geological storage formations show that 94.8% of the point emission sources (accounting for 97.1% of annual total emissions) can find at least one candidate geological storage formation in its adjacent areas. This means that, for Chongqing, the CO2 transport cost is likely very low. The research findings indicate that there is great potential for CO2 geological storage technology to deploy in Chongqing and for this technology to deliver profound and sustaining impacts on reducing CO2 emissions and developing low-carbon economy in Chongqing. This preliminary study is expected to stimulate more researches, critical thinking and policy actions to promote positive measures to reduce greenhouse gas emissions so as to mitigate the impact of global climate change, as well as to set a good example for other regions in China.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 7 M.D. Ruiz-Medina, R.M. Espejo Montes Functional Statistics provides a suitable framework for the analysis of large dimensional data sets. In this paper, we consider the spatial autoregressive functional series (SARH(1)) framework. This framework allows the incorporation of spatial interaction to the statistical analysis of functional data (see Ruiz-Medina [1] , [2] ). The SARH(1) model is fitted to the average ocean temporal temperature profiles, collected in different spatial locations, during the years 1998, 1999 and 2000. We have used the public oceanographic bio-optical database, The World-wide Ocean Optics Database (WOOD). The SARH(1) plug-in extrapolator is then computed, from the previously derived infinite-dimensional projection parameter estimator.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 3 Fabio Sigrist, Hans R. Künsch, Werner A. Stahel A spatio-temporal model for precipitation is presented. It is assumed that precipitation follows a censored and power-transformed normal distribution. Through a regression term, precipitation is linked to covariates. Spatial and temporal dependencies are accounted for by a latent Gaussian variable that follows a Markovian temporal evolution combined with spatially correlated innovations. Such a specification allows for nonseparable covariances in space and time. Further, the Markovian structure yields computational efficiency and it exploits in a natural way the unidirectional flow of time. In addition, the model is space as well as time resolution consistent. The model is applied to three-hourly Swiss rainfall data, collected at 26 stations.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 11, Part B Shuzhou Wang, Bo Meng Support Vector Machine (SVM) is a new modeling method. It has shown good performance in many field and mostly outperformed neural networks. The parameter selection should to be done before training SVM. Modified particle swarm optimization (POS) was adpoted to select parameters of SVM. It is shown by simulation that the modified POS algorithm can derive a set of optimal parameters of SVM. Compared with neural networks, SVM model possess some advantages such as simple structure, fast convergence speed with high generalization ability.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 11, Part A Li Xiaonian, Zhu Yi, Zhang Fuhao, Liu Xiaodong According to domestic and foreign rural geographic information system construction, this article points out the problems of domestic new socialist countryside construction. Combined with the reality of Xinjiang new socialist countryside construction, it has constructed the geographic information platform of new socialist countryside comprehensive services, which is easier to realize farmland protection, cadastre management, central village plan and many other basic services in rural areas, and provided reliable and real-time information technology services for Xinjiang new socialist countryside construction.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 9 Lino José Alvarez-Vázquez, Aurea Martínez, Miguel Ernesto Vázquez-Méndez, Miguel Angel Vilar The main objective of this work is showing how numerical simulation and optimal control theory can be useful tools in practical ecological engineering. We take attention into diadromous fish (salmon, trout, eel…) and their river migrations, and particularly, we focus on fishways, hydraulic structures that enable fish to overcome stream obstructions as dams or weirs. We use mathematical modelling to formulate the problems of design and management of a fishway providing a good hydraulic performance for fish. By solving these problems for a standard vertical slot fishway, we can observe that controlling the flux of inflow water is a useful technique for the management of an already built fishway, but a correct shape design is mandatory in order to guarantee a correct hydraulic performance, especially for a new fishway.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 5 Dacheng Liu, Ning Li, Xianchun Tan, Xiaoou Yang, Li Wang, Jianbing Liu Chinese government committed to reducing carbon dioxide emissions per unit of GDP by 40% to 45% by 2020. As the capital and one of the biggest cites, Beijing expected to both keep higher GDP growth than average and cut unit GDP carbon emission, and has to adjust the relevant energy strategy in near future. The paper analysis the characteristics of energy supply and energy consumption in Beijing, and setups the economic-energy-environment-oriented reference energy system (RES), selects MARKAL as the optimal model and constructs districted multi-period linear programming matrix, which including 15 energy carriers, 4 energy processes, 17 energy conversions, and 18 energy end-use sets. Furthermore, the paper designs 11 scenarios in various pollute emission restrictions, and establishes the total economic cost as the optimize target, the low-carbon emission as main restriction, to obtain the suitable energy supply structure and end-use technology structure. At last, we have the conclusion that Beijing can attach the demands of cutting carbon emissions per unit of GDP by 45% under the scheduled GDP growth.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 4 Elena Paoletti, Tommaso Bardelli, Gianluca Giovannini, Leonella Pecchioli The Urban Forest Effects (UFORE) model, a computer model designed to use tree allometric, air pollution and meteorological data to statistically estimate urban forest characteristics and various urban forest functions, was applied to the main park in the city of Florence, Italy (Cascine Park), in 1985 and 2004, in order to study how the natural and man-made evolution of the park affected its ability to control air quality. Plant data were for both the years, while climate and pollutant data were for year 2004 only, in order to remove the variability due to changes in the atmospheric variables. The results show that the forest growth compensated the losses due to cuttings and damages by extreme climatic events, so that the overall amount of pollutants removed from the air did not change from 1985 to 2004 (72.4–69.0 kg/ha). In contrast, the amount of carbon storing and biogenic volatile organic compound emission decreased over time, because of a reduction in the number of large trees and of isoprene-emitting individuals, but the results were very variable plot by plot. The species were ranked according to their ability of controlling air quality. These data can be used as a decision tool for establishing cuttings and new plantings in urban planning and their effects on air quality under Mediterranean climate conditions.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 10, Part C Liu-Zhihong, Yu-Jinhui, Zhang-Deng Under the low-carbon time of globalization, Guangxi Zhuang Autonomous Region as the one of the many provinces in western China, it is necessary that to open Beibu Gulf for getting sustainable development in the new time and situation. Exactly the basic way for the development is the strategy of sustainable development that of construction Beibu Gulf economic zone consist of low-carbon, ecological and harmonious. With the development and construction of Beibu Gulf, a lot of towns are stepping into the progress of urbanization one by one. However, in the background for urbanization of ecological and low-carbon, study on low-carbon building and ecological city construction in harmonious Beibu Gulf culture that would be necessary and of great significance.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 5 Shaoqing Chen, Bin Chen, Meirong Su The importance of addressing cumulative environmental impact of large development projects on rivers has been increasingly highlighted. Consideration to potential impact pathways may be difficult, however, without appropriate analytical methods. By introducing ecological network model, this paper focuses on the quantification of the cause-effect relationships inherent the cumulative effects of dam construction from a holistic perspective. With Lancang river of Longitudinal Range-Gorge Region (LRGR) as an example, the risk-based interaction instead of the conventional energy or material flow of ecological network model has been created to conceptualize the cumulative effects network model. Based on this model, the network structural and functional analysis were adjusted for the assessment of potential eco-environmental impact within the ecosystem, thus demonstrating how the risk-based ecological network analysis can be used to characterize the holistic cumulative effects of dams on the temporal and spatial scale.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 7 Daniel K. Heersink, Reinhard Furrer Modern compaction rollers monitor soil properties by observing vibrational characteristics of the soil. A vibrating drum traverses the compaction site measuring soil stiffness and collecting GPS coordinates that are together termed roller measurement values (RMVs). These RMVs can be modeled as a random spatial field and additively decomposed into any sensible combination of mean terms, spatial terms, spline terms, and ridge regression terms. The goal of this modeling is to implement intelligent compaction for quality control and quality assurance purposes. Proper modeling of such data (stationarity, anisotropy,.) is then of paramount concern. Each layer of the compaction site can be modeled by the n-vector y = Xβ+α+γ+ ɛ, where Xβ is a low-order (linear) polynomial trend, α is a mean term estimated using ridge regression or splines modeling the large-scale variation, γ is a (zero-mean Gaussian) spatial process modeling the small-scale variation, and ɛ is the noise. Here, X is the (n × p) design matrix with rank p. There are many general approaches to working with such an additive mixed model, including a backfitting procedure for maximum-likelihood estimation and generalized cross-validation. Due to computational complexity of maximum-likelihood estimation a backfitting procedure, Furrer and Sain (2009) [1] , was extended to the more general models used here and employed in the estimation. The extended backfitting procedure has been shown to converge and the iterative least-squares estimates have been shown to converge to the generalized least-squares estimate. A simulation study has been conducted to analyze estimates of this general model using a penalized likelihood and generalized cross-validation (GCV) approach as well. Results of the cross-validation study using a spline structure indicate there are some random fields that can be generated that do not have a minimum GCV.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 4 S.M. Salim, R. Buccolieri, A. Chan, S. Di Sabatino, S.C. Cheah This paper presents numerical simulations of the aerodynamic effects of trees on the flow field and dispersion of trafficoriginated pollutants in an urban street canyon of W/H = 1 with a perpendicular approach flow. Large Eddy Simulation (LES) is employed for the investigation and is validated against wind tunnel (WT) experiment. Comparisons is made between an empty street canyon and one containing avenue-like tree planting of pore volume, Pvol = 96%. In the presence of trees, both measurements and simulations show considerably larger pollutant concentrations near the leeward wall and slightly lower concentrations near the windward wall in comparison to the tree-free case.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 10, Part B Shuo Zhou, Zongxing Chen, Xiaoyang Liu, Hao Tang In this paper we focus on augment reality (AR) used in mobile device and analysis advantages of touch-screen devices in facilitating user experience for elder people. We developed a virtual system on symbian^3 platform considering the characteristic of elder people. The assessment of the system at the end suggests the potential of mobile AR for elders.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 6 Muhammad Afzal, Martin G. Mansell, Alexandre S. Gagnon The objective of this research is to analyse temporal changes in historic rainfall variability across Scotland using different measures of variability. The CUSUM and sequential Mann-Kendall test applied to records from 28 weather stations with up to 80 years of daily precipitation data reveal the occurrence of abrupt changes in the rainfall trends. Most weather stations show a turning point between 1978 and 1985, although some stations situated in Eastern Scotland have more than one turning point. The temporal changes in rainfall variability across Scotland are presented using a number of measures of variability.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 9 Adil Baghli, Philippe Thiévent R&D activities at Egis Environnement (a civil engineering-based environmental consultancy) facilitated the development of OptiFlux, a spatial analysis tool designed to predict and visualize the effects of implementing a linear infrastructure upon wildlife habitats. It also tests the relevance of positioning fauna passages to ensure the restoration of habitat connectivity and therefore allows the optimization of the number and location of potential fauna passages. OptiFlux makes use of habitat quality maps which correlated with ecological requirements of each studied species. The concept is based on the evaluation of the spatial distribution of wildlife in their natural habitats. It also allows the evaluation of the impact of a project that modifies landscape structures and contributes to territory fragmentation. OptiFlux is a project optimization instrument which helps in the decisionmaking process. Major applications are: • Identification of routes with the least impact on wildlife population fluxes and their habitats, • Optimization of the number and location of fauna passages for the benefit of wildlife and reduction of the conflict points between infrastructures (road, highway, railway) and ecological networks, • Simulation of the positive effects of the proposed fauna passages or biotopes (amphibian ponds, for example) for a better choice of installations and for a better reconnection of the fragmented habitats.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 11, Part C Zhou Yan, Jing Guang-e, Liu Xiao-hui, Li Qing-ling Theoretical research and numerical simulation for ventilation properties of solar chimney with vertical collector are performanced and they are compared with experimental results. Results show that: there are many factors to affect solar chimney ventilation that include heat collection height and width, solar radiation intensity, inlet and outlet area ratio of chimney and air inlet velocity, etc. When the collector height is increased, chimney ventilation is getting higher; but the ventilation increases slowly even decreases; the ventilation increases first and then decreases as the growing of the air layer thickness under the same chimney height and width; there exists an optimal ratio between heat collector height and width which makes the ventilation largest; considering the urban architecture image and the influence of the air layer thickness on chimney ventilation, the best air layer thickness is between 0.2m and 0.4m. Besides, the airflow temperature in solar chimney increases with chimney height in certain solar radiation intensity. It is consistent with the theoretical analysis and simulation results.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 8

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 10, Part A Ye Yun, Xu Xi-shan, Qi Zhi-chang To protect critical resources in networked environments, it is important to quantify the likelihood of potential multi- step attacks in attack graphs. Aimed at the problems that probabilistic incorrect computing caused by shared dependencies in nodes, a methodology for security risk analysis that is based on the model of attack graphs and the Common Vulnerability Scoring System (CVSS) was presented, and the problem of probabilistic incorrect computing was solved successfully by proposing the probabilistic computing approach of accurate calculation and approximate calculation, While ensuring the accuracy of the probability of attack graph-based nodes, quickly Calculated the probability of each node, which can be adapted to a large-scale network. Reasonableness and effectiveness of proposed method was verified in the simulation. Compared with the related research, our approach can be adapted to a more complex attack graph, and had good scalability.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 11, Part A Xin Jin, Xin Zhou Electric power enterprises are one important part of pillar industries in our country. There are many factors to cause risks which might bring trouble and disaster, so that we ought to manage those risks so as to reduce and avoid those risks, therefore we need to evaluate the risks which could happen. In this paper, in order to evaluate the risks of some thermal power enterprises in East China which are belong to one power group, we use text content analysis method to analyze a lot of risk exploration reports to build risk evaluation index system and every index’ weight, then evaluate risk level for every risk factor with AHP, and discuss the risk comprehensive evaluation of enterprises.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 8 Suqin Li, Xue Zhang Reverse osmosis approach was used to dispose pulp and paper wastewater from a papermaking company. To meet the requirements of reverse osmosis membranes for water quality, a proper pretreatment had been done before raw water into RO membranes. A new efficient composite flocculant named PAFSSB had been used in the pre-treatment of pulp and paper wastewater. In the paper, the results showed that the treatment effect of PAFSSB was better, COD content was down to 10 mg/L and COD removal rate was up to 75%. The pre-treatment process was simplified and processing costs were reduced.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 3 Sarah E. Nevillea, M.P. Wand We devise a variational Bayes algorithm for fast approximate inference in Bayesian Generalized Extreme Value additive model analysis. Such models are useful for flexibly assessing the impact of continuous predictor variables on sample extremes. The new methodology allows large Bayesian models to be fitted and assessed without the significant computing costs of Monte Carlo methods. © 2010 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Alfred Stein.

Description: Publication year: 2011 Source: Procedia Environmental Sciences, Volume 10, Part A Wang Yong, Liu Yanping, Su Youpo According to the GPS data provided by International GNSS Service, the author adopted the software of GAMIT/GLOBK to solve the GPS data. The deformation of GPS stations’ coordinates during the Mw 9.0 Japan Earthquake was achieved which was utilized to infer physical processes at earthquake sources. It was computed six GPS stations’ data by GAMIT/GLOBK software and analyzed the GPS stations’ coordinate series. The changes of six stations were subsiding in the Vertical direction, while the changes of each station were moving north in the earthquake time in the North direction. The change values among KGNI, TSK2 and TSKB in North and Vertical direction reached 0.4m, or nearly 0.5m. It can be concluded that KGNI, TSK2 and TSKB were greater changes in the earthquake, which were close to the earthquake epicenter.

Description: Pore formation during dehydration of a polycrystalline gypsum sample observed and quantified in a time-series synchrotron X-ray micro-tomography experiment Solid Earth, 3, 71-86, 2012 Author(s): F. Fusseis, C. Schrank, J. Liu, A. Karrech, S. Llana-Fúnez, X. Xiao, and K. Regenauer-Lieb We conducted an in-situ X-ray micro-computed tomography heating experiment at the Advanced Photon Source (USA) to dehydrate an unconfined 2.3 mm diameter cylinder of Volterra Gypsum. We used a purpose-built X-ray transparent furnace to heat the sample to 388 K for a total of 310 min to acquire a three-dimensional time-series tomography dataset comprising nine time steps. The voxel size of 2.2 μm 3 proved sufficient to pinpoint reaction initiation and the organization of drainage architecture in space and time. We observed that dehydration commences across a narrow front, which propagates from the margins to the centre of the sample in more than four hours. The advance of this front can be fitted with a square-root function, implying that the initiation of the reaction in the sample can be described as a diffusion process. Novel parallelized computer codes allow quantifying the geometry of the porosity and the drainage architecture from the very large tomographic datasets (2048 3 voxels) in unprecedented detail. We determined position, volume, shape and orientation of each resolvable pore and tracked these properties over the duration of the experiment. We found that the pore-size distribution follows a power law. Pores tend to be anisotropic but rarely crack-shaped and have a preferred orientation, likely controlled by a pre-existing fabric in the sample. With on-going dehydration, pores coalesce into a single interconnected pore cluster that is connected to the surface of the sample cylinder and provides an effective drainage pathway. Our observations can be summarized in a model in which gypsum is stabilized by thermal expansion stresses and locally increased pore fluid pressures until the dehydration front approaches to within about 100 μm. Then, the internal stresses are released and dehydration happens efficiently, resulting in new pore space. Pressure release, the production of pores and the advance of the front are coupled in a feedback loop.

Description: Coupling of climate models and ice sheet models by surface mass balance gradients: application to the Greenland Ice Sheet The Cryosphere, 6, 255-272, 2012 Author(s): M. M. Helsen, R. S. W. van de Wal, M. R. van den Broeke, W. J. van de Berg, and J. Oerlemans It is notoriously difficult to couple surface mass balance (SMB) results from climate models to the changing geometry of an ice sheet model. This problem is traditionally avoided by using only accumulation from a climate model, and parameterizing the meltwater run-off as a function of temperature, which is often related to surface elevation ( H s ). In this study, we propose a new strategy to calculate SMB, to allow a direct adjustment of SMB to a change in ice sheet topography and/or a change in climate forcing. This method is based on elevational gradients in the SMB field as computed by a regional climate model. Separate linear relations are derived for ablation and accumulation, using pairs of H s and SMB within a minimum search radius. The continuously adjusting SMB forcing is consistent with climate model forcing fields, also for initially non-glaciated areas in the peripheral areas of an ice sheet. When applied to an asynchronous coupled ice sheet – climate model setup, this method circumvents traditional temperature lapse rate assumptions. Here we apply it to the Greenland Ice Sheet (GrIS). Experiments using both steady-state forcing and glacial-interglacial forcing result in realistic ice sheet reconstructions.

Description: Estimating ice phenology on large northern lakes from AMSR-E: algorithm development and application to Great Bear Lake and Great Slave Lake, Canada The Cryosphere, 6, 235-254, 2012 Author(s): K.-K. Kang, C. R. Duguay, and S. E. L. Howell Time series of brightness temperatures ( T B ) from the Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E) are examined to determine ice phenology variables on the two largest lakes of northern Canada: Great Bear Lake (GBL) and Great Slave Lake (GSL). T B measurements from the 18.7, 23.8, 36.5, and 89.0 GHz channels (H- and V- polarization) are compared to assess their potential for detecting freeze-onset/melt-onset and ice-on/ice-off dates on both lakes. The 18.7 GHz (H-pol) channel is found to be the most suitable for estimating these ice dates as well as the duration of the ice cover and ice-free seasons. A new algorithm is proposed using this channel and applied to map all ice phenology variables on GBL and GSL over seven ice seasons (2002–2009). Analysis of the spatio-temporal patterns of each variable at the pixel level reveals that: (1) both freeze-onset and ice-on dates occur on average about one week earlier on GBL than on GSL (Day of Year (DY) 318 and 333 for GBL; DY 328 and 343 for GSL); (2) the freeze-up process or freeze duration (freeze-onset to ice-on) takes a slightly longer amount of time on GBL than on GSL (about 1 week on average); (3) melt-onset and ice-off dates occur on average one week and approximately four weeks later, respectively, on GBL (DY 143 and 183 for GBL; DY 135 and 157 for GSL); (4) the break-up process or melt duration (melt-onset to ice-off) lasts on average about three weeks longer on GBL; and (5) ice cover duration estimated from each individual pixel is on average about three weeks longer on GBL compared to its more southern counterpart, GSL. A comparison of dates for several ice phenology variables derived from other satellite remote sensing products (e.g. NOAA Interactive Multisensor Snow and Ice Mapping System (IMS), QuikSCAT, and Canadian Ice Service Database) show that, despite its relatively coarse spatial resolution, AMSR-E 18.7 GHz provides a viable means for monitoring of ice phenology on large northern lakes.

Description: On the representation of immersion and condensation freezing in cloud models using different nucleation schemes Atmospheric Chemistry and Physics Discussions, 12, 7167-7209, 2012 Author(s): B. Ervens and G. Feingold Ice nucleation in clouds is often observed at temperatures 〉235 K, pointing to heterogeneous freezing as a predominant mechanism. Many models deterministically predict the number concentration of ice particles as a function of temperature and/or supersaturation. Laboratory experiments at constant temperature and/or supersaturation often report heterogeneous freezing as a stochastic, time-dependent process that follows classical nucleation theory which might appear to contradict singular freezing behavior. We explore the extent to which the choice of nucleation scheme (deterministic/stochastic, single/multiple contact angles θ) affects the prediction of the frozen ice nuclei (IN) fraction and cloud evolution. A box model with constant temperature and supersaturation is used to mimic published laboratory experiments of immersion freezing of kaolinite (~243 K), and the fitness of different nucleation schemes. Sensitivity studies show that agreement of all five schemes is restricted to the narrow parameter range (time, temperature, IN diameter) in the original laboratory studies. The schemes are implemented in an adiabatic parcel model that includes feedbacks of the formation and growth of drops and ice particles on supersaturation during the ascent of an air parcel. Model results show that feedbacks of droplets and ice on supersaturation limit ice nucleation events, often leading to smaller differences in number concentration of ice particles and ice water content (IWC) between stochastic and deterministic approaches than expected from the box model studies. However, the different parameterizations of θ distributions and time-dependencies are highly sensitive to IN size and can lead to great differences in predicted ice number concentrations and IWC between the different schemes. Finally, since the choice of nucleation scheme determines the temperature range over which nucleation occurs, at habit-prone temperatures (~253 K) different onset temperatures of freezing create variability in the initial inherent growth ratio of ice particles, which can lead to amplification or reduction in differences in predicted IWC.

Description: A sun-tracking method to improve the pointing accuracy of weather radar Atmospheric Measurement Techniques, 5, 547-555, 2012 Author(s): X. Muth, M. Schneebeli, and A. Berne Accurate positioning of data collected by a weather radar is of primary importance for their appropriate georeferencing, which in turn makes it possible to combine those with additional sources of information (topography, land cover maps, meteorological simulations from numerical weather models to list a few). This issue is especially acute for mobile radar systems, for which accurate and stable leveling might be difficult to ensure. The sun is a source of microwave radiation, which can be detected by weather radars and used for accurate positioning of radar data. This paper presents a technique based on the similarity between theodolites and radar systems as well as on the sun echoes to quantify and hence correct the instrumental errors which can affect the pointing accuracy of radar antenna. The proposed method is applied to data collected in the Swiss Alps using a mobile X-band radar system. The obtained instrumental bias values are evaluated by comparing the locations of the ground echoes predicted using these bias estimates with the observed ground echo locations. The very good agreement between the two confirms the accuracy of the proposed method.

Description: A multi-model assessment of the efficacy of sea spray geoengineering Atmospheric Chemistry and Physics Discussions, 12, 7125-7166, 2012 Author(s): K. J. Pringle, K. S. Carslaw, T. Fan, G.W. Mann, A. Hill, P. Stier, K. Zhang, and H. Tost Artificially increasing the albedo of marine clouds by the mechanical emission of sea spray aerosol has been proposed as a geoengineering technique to slow the warming caused by anthropogenic greenhouse gases. A previous global model study found that only modest increases and sometimes even decreases in cloud drop number (CDN) concentrations would result from plausible emission scenarios. Here we extend that work to examine the conditions under which decreases in CDN can occur, and use three independent global models to quantify maximum achievable CDN changes. We find that decreases in CDN can occur when at least three of the following conditions are met: the injected particle number is 250–300 nm, the background aerosol loading is large (≥150 cm −3 ) and the in-cloud updraught velocity is low (

Description: Effects of seawater p CO 2 changes on the calcifying fluid of scleractinian corals Biogeosciences Discussions, 9, 2655-2689, 2012 Author(s): S. Hohn and A. Merico Rising atmospheric CO 2 concentrations due to anthropogenic emissions induce changes in the ocean carbonate chemistry and a drop in ocean pH. This acidification process is expected to harm calcifying organisms like coccolithophores, molluscs, echinoderms, and corals. A severe decline in coral abundance is, for example, expected by the end of this century with associated disastrous effects on reef ecosystems. Despite the growing importance of the topic, little progress has been made with respect to modelling the impact of acidification on coral calcification. Here we present a model for a coral polyp that simulates the carbonate system in four different compartments: the seawater, the polyp tissue, the coelenteron, and the calicoblastic layer. Precipitation of calcium carbonate takes place in the metabolically controlled calicoblastic layer beneath the polyp tissue. The model is adjusted to a state of activity as observed by direct microsensor measurements in the calcifying fluid. Simulated CO 2 perturbation experiments reveal decreasing calcification rates under elevated p CO 2 despite strong metabolic control of the calcifying fluid. Diffusion of CO 2 through the tissue into the calicoblastic layer increases with increasing seawater p CO 2 leading to decreased aragonite saturation in the calcifying fluid of the coral polyp. Our modelling study provides important insights into the complexity of the calcification process at the organism level and helps to quantify the effect of ocean acidification on corals.

Description: The role of the seagrass Posidonia oceanica in the cycling of trace elements Biogeosciences Discussions, 9, 2623-2653, 2012 Author(s): C. Sanz-Lázaro, P. Malea, E. T. Apostolaki, I. Kalantzi, A. Marín, and I. Karakassis The aim of this work was to study the role of the seagrass Posidonia oceanica on the cycling of a wide set of trace elements (Ag, As, Ba, Bi, Cd, Co, Cr, Cs, Cu, Fe, Ga, Li, Mn, Ni, Pb, Rb, Sr, Tl, V and Zn). We measured the concentration of these trace elements in the different compartments of P. oceanica (leaves, rhizomes, roots and epibiota) in a non-polluted seagrass meadow representative of the Mediterranean and calculated the annual budget from a mass balance. We provide novel data on accumulation dynamics of many trace elements in P. oceanica compartments and demonstrate that trace element accumulation patterns are mainly determined by plant compartment rather than by temporal variability. Epibiota was the compartment which showed the greatest concentrations for most trace elements. Thus, they constitute a key compartment when estimating trace element transfer to higher trophic levels by P. oceanica . For most trace elements, translocation seemed to be low and acropetal. Zn, Cd, Sr and Rb were the trace elements that showed the highest release rate through decomposition of plant detritus, while Cs, Tl and Bi the lowest. P. oceanica acts as a sink of potentially toxic trace elements (Ni, Cr, As and Ag), which can be sequestered, decreasing their bioavailability. P. oceanica may have a relevant role in the cycling of trace elements in the Mediterranean.

Description: Smoke aerosol and its radiative effects during extreme fire event over Central Russia in summer 2010 Atmospheric Measurement Techniques, 5, 557-568, 2012 Author(s): N. Chubarova, Ye. Nezval', I. Sviridenkov, A. Smirnov, and I. Slutsker Different microphysical, optical and radiative properties of aerosol were analyzed during the severe fires in summer 2010 over Central Russia using ground measurements at two AERONET sites in Moscow (Meteorological Observatory of Moscow State University – MSU MO) and Zvenigorod (Moscow Region) and radiative measurements at the MSU MO. Volume aerosol size distribution in smoke conditions had a bimodal character with the significant prevalence of fine mode particles, for which effective radius was shifted to higher values ( r eff-fine = 0.24 μm against approximately 0.15 μm in typical conditions). For smoke aerosol, the imaginary part of refractive index (REFI) in the visible spectral region was lower than that for typical aerosol (REFI λ =675 nm = 0.006 against REFI λ =675 nm = 0.01), while single scattering albedo (SSA) was significantly higher (SSA λ =675 nm = 0.95 against SSA λ =675 nm ~ 0.9). Extremely high aerosol optical thickness at 500 nm (AOT500) was observed on 6–8 August reaching the absolute maximum on 7 August in Moscow (AOT500 = 6.4) and at Zvenigorod (AOT500 = 5.9). A dramatic attenuation of solar irradiance at ground was also recorded. Maximum irradiance loss had reached 64% for global shortwave irradiance, 91% for UV radiation 300–380 nm, and 97% for erythemally-weighted UV irradiance at relatively high solar elevation 47°. Significant spectral dependence in attenuation of solar irradiance in smoky conditions was mainly explained by higher AOT and smaller SSA in UV (0.8–0.9) compared with SSA in the visible region of spectrum. The assessments of radiative forcing effect (RFE) at the TOA indicated a significant cooling of the smoky atmosphere. Instant RFE reached −167 Wm −2 at AOT500 = 6.4, climatological RFE calculated with August 2010 monthly mean AOT was about −65 Wm −2 , compared with −20 Wm −2 for typical aerosol according to the 10 yr period of measurements in Moscow.

Description: Fire history in western Patagonia from paired tree-ring fire-scar and charcoal records Climate of the Past, 8, 451-466, 2012 Author(s): A. Holz, S. Haberle, T. T. Veblen, R. De Pol-Holz, and J. Southon Fire history reconstructions are typically based on tree ages and tree-ring fire scars or on charcoal in sedimentary records from lakes or bogs, but rarely on both. In this study of fire history in western Patagonia (47–48° S) in southern South America (SSA) we compared three sedimentary charcoal records collected in bogs with tree-ring fire-scar data collected at 13 nearby sample sites. We examined the temporal and spatial correspondence between the two fire proxies and also compared them to published charcoal records from distant sites in SSA, and with published proxy reconstructions of regional climate variability and large-scale climate modes. Two of our three charcoal records record fire activity for the last 4 ka yr and one for the last 11 ka yr. For the last ca. 400 yr, charcoal accumulation peaks tend to coincide with high fire activity in the tree-ring fire scar records, but the charcoal records failed to detect some of the fire activity recorded by tree rings. Potentially, this discrepancy reflects low-severity fires that burn in herbaceous and other fine fuels without depositing charcoal in the sedimentary record. Periods of high fire activity tended to be synchronous across sample areas, across proxy types, and with proxy records of regional climatic variability as well as major climate drivers. Fire activity throughout the Holocene in western Patagonia has responded to regional climate variation affecting a broad region of southern South America that is teleconnected to both tropical- and high-latitude climate drivers-El Niño-Southern Oscillation and the Southern Annular Mode. An early Holocene peak in fire activity pre-dates any known human presence in our study area, and consequently implicates lightning as the ignition source. In contrast, the increased fire activity during the 20th century, which was concomitantly recorded by charcoal from all the sampled bogs and at all fire-scar sample sites, is attributed to human-set fires and is outside the range of variability characteristic of these ecosystems over many centuries and probably millennia.

Description: Exploring errors in paleoclimate proxy reconstructions using Monte Carlo simulations: paleotemperature from mollusk and coral geochemistry Climate of the Past, 8, 433-450, 2012 Author(s): M. Carré, J. P. Sachs, J. M. Wallace, and C. Favier Quantitative reconstructions of the past climate statistics from geochemical coral or mollusk records require quantified error bars in order to properly interpret the amplitude of the climate change and to perform meaningful comparisons with climate model outputs. We introduce here a more precise categorization of reconstruction errors, differentiating the error bar due to the proxy calibration uncertainty from the standard error due to sampling and variability in the proxy formation process. Then, we propose a numerical approach based on Monte Carlo simulations with surrogate proxy-derived climate records. These are produced by perturbing a known time series in a way that mimics the uncertainty sources in the proxy climate reconstruction. A freely available algorithm, MoCo, was designed to be parameterized by the user and to calculate realistic systematic and standard errors of the mean and the variance of the annual temperature, and of the mean and the variance of the temperature seasonality reconstructed from marine accretionary archive geochemistry. In this study, the algorithm is used for sensitivity experiments in a case study to characterize and quantitatively evaluate the sensitivity of systematic and standard errors to sampling size, stochastic uncertainty sources, archive-specific biological limitations, and climate non-stationarity. The results of the experiments yield an illustrative example of the range of variations of the standard error and the systematic error in the reconstruction of climate statistics in the Eastern Tropical Pacific. Thus, we show that the sample size and the climate variability are the main sources of the standard error. The experiments allowed the identification and estimation of systematic bias that would not otherwise be detected because of limited modern datasets. Our study demonstrates that numerical simulations based on Monte Carlo analyses are a simple and powerful approach to improve the understanding of the proxy records. We show that the standard error for the climate statistics linearly increases with the climate variability, which means that the accuracy of the error estimated by MoCo is limited by the climate non-stationarity.

Description: The relative roles of CO 2 and palaeogeography in determining Late Miocene climate: results from a terrestrial model-data comparison Climate of the Past Discussions, 8, 715-786, 2012 Author(s): C. D. Bradshaw, D. J. Lunt, R. Flecker, U. Salzmann, M. J. Pound, A. M. Haywood, and J. T. Eronen The Late Miocene (∼11.6–5.3 Ma) palaeorecord provides evidence for a warmer and wetter climate than that of today and there is uncertainty in the palaeo-CO 2 record of at least 150 ppmv. We present results from fully coupled atmosphere-ocean-vegetation simulations for the Late Miocene that examine the relative roles of palaeogeography (topography and ice sheet geometry) and CO 2 concentration in the determination of Late Miocene climate through comprehensive terrestrial model-data comparisons. Assuming that the data accurately reflects the Late Miocene climate, and that the Late Miocene palaeogeographic reconstruction used in the model is robust, then results indicate that the proxy-derived precipitation differences between the Late Miocene and modern can be largely accounted for by the palaeogeographic changes alone. However, the proxy-derived temperatures differences between the Late Miocene and modern can only begin to be accounted for if we assume a palaeo-CO 2 concentration towards the higher end of the range of estimates.

Description: Changes in the strength and width of the Hadley circulation since 1871 Climate of the Past Discussions, 8, 695-713, 2012 Author(s): J. Liu, M. Song, Y. Hu, and X. Ren Recent studies demonstrate that the Hadley Circulation has intensified and expanded for the past three decades, which has important implications for subtropical societies and may lead to profound changes in global climate. However, the robustness of this intensification and expansion that should be considered when interpreting long-term changes of the Hadley Circulation is still matters of debate. It also remains largely unknown how the Hadley Circulation has evolved over longer periods. Here we present long-term variability of the Hadley Circulation using the 20th Century Reanalysis. It shows a slight strengthening and widening of the Hadley Circulation since the late 1970s, which is not inconsistent with recent assessments. However, over centennial timescales (1871–2008), the Hadley Circulation shows a tendency towards more intense and narrower state. More importantly, the width of the Hadley Circulation has not yet completed a life-cycle since 1871. The strength and width of the Hadley Circulation during the late 19th and early 20th century show strong natural variability, exceeding variability that coincides with global warming in recent decades. These findings raise the question that the recent change of the Hadley Circulation is primarily attributed to greenhouse warming or a long-period oscillation of the Hadley Circulation substantially longer than that observed in previous studies.

Description: Towards a regional ocean forecasting system for the IBI (Iberia-Biscay-Ireland area): developments and improvements within the ECOOP project framework Ocean Science, 8, 143-159, 2012 Author(s): S. Cailleau, J. Chanut, J.-M. Lellouche, B. Levier, C. Maraldi, G. Reffray, and M. G. Sotillo The regional ocean operational system remains a key element in downscaling from large scale (global or basin scale) systems to coastal ones. It enables the transition between systems in which the resolution and the resolved physics are quite different. Indeed, coastal applications need a system to predict local high frequency events (inferior to the day) such as storm surges, while deep sea applications need a system to predict large scale lower frequency ocean features. In the framework of the ECOOP project, a regional system for the Iberia-Biscay-Ireland area has been upgraded from an existing V0 version to a V2. This paper focuses on the improvements from the V1 system, for which the physics are close to a large scale basin system, to the V2 for which the physics are more adapted to shelf and coastal issues. Strong developments such as higher regional physics resolution in the NEMO Ocean General Circulation Model for tides, non linear free surface and adapted vertical mixing schemes among others have been implemented in the V2 version. Thus, regional thermal fronts due to tidal mixing now appear in the latest version solution and are quite well positioned. Moreover, simulation of the stratification in shelf areas is also improved in the V2.

Description: Arctic sea ice variability and trends, 1979–2010 The Cryosphere Discussions, 6, 957-979, 2012 Author(s): D. J. Cavalieri and C. L. Parkinson Analyses of 32 yr (1979–2010) of Arctic sea ice extents and areas derived from satellite passive microwave radiometers are presented for the Northern Hemisphere as a whole and for nine Arctic regions. There is an overall negative yearly trend of −51.5 ± 4.1 × 10 3 km 2 yr −1 (−4.1 ± 0.3% decade −1 ) in sea ice extent for the hemisphere. The sea ice extent trends for the individual Arctic regions are all negative except for the Bering Sea: −3.9 ± 1.1 × 10 3 km 2 yr −1 (−8.7 ± 2.5% decade −1 ) for the Seas of Okhotsk and Japan, +0.3 ± 0.8 × 10 3 km 2 yr −1 (+1.2 ± 2.7% decade −1 ) for the Bering Sea, −4.4 ± 0.7 × 10 3 km 2 yr −1 (−5.1 ± 0.9% decade −1 ) for Hudson Bay, −7.6 ± 1.6 × 10 3 km 2 yr −1 (−8.5 ± 1.8% decade −1 ) for Baffin Bay/Labrador Sea, −0.5 ± 0.3 × 10 3 km 2 yr −1 (−5.9 ± 3.5% decade −1 ) for the Gulf of St. Lawrence, −6.5 ± 1.1 × 10 3 km 2 yr −1 (−8.6 ± 1.5% decade −1 ) for the Greenland Sea, −13.5 ± 2.3 × 10 3 km 2 yr −1 (−9.2 ± 1.6% decade −1 ) for the Kara and Barents Seas, −14.6 ± 2.3 × 10 3 km 2 yr −1 (−2.1 ± 0.3% decade −1 ) for the Arctic Ocean, and −0.9 ± 0.4 × 10 3 km 2 yr −1 (−1.3 ± 0.5% decade −1 ) for the Canadian Archipelago. Similarly, the yearly trends for sea ice areas are all negative except for the Bering Sea. On a seasonal basis for both sea ice extents and areas, the largest negative trend is observed for summer with the next largest negative trend being for autumn.

Description: Publication year: 2012 Source: Geoscience Frontiers Jinyang Zhang, Changqian Ma, Zhenbing She The Erlangmiao granite intrusion is located in the eastern part of the East Qinling Orogen. The granite contains almost 99 vol.% felsic minerals with accessory garnet, muscovite, biotite, zircon, and Fe-Ti oxide. Garnet is the dominant accessory mineral, shows zoned texture, and is rich in w (FeO) (14.13%–16.09%) and w (MnO) (24.21%–27.44%). The rocks have high SiO 2 , alkalis, FeO t /MgO, TiO 2 /MgO and low Al 2 O 3 , CaO with w (Na 2 O)/ w (K 2 O)〉 1. Their Rb, Ga, Ta, Nb, Y, and Yb contents are high and Sr, Ba, Eu, Zr, P, and Ti contents are low. These features indicate that the Erlangmiao granite is a highly evolved metaluminous A-type. Garnet crystallized at the expense of biotite from the MnO-rich evolved melt after fractionation of biotite, plagioclase, K-feldspar, zircon, apatite, and ilmenite. The relatively high initial 87 Sr/ 86 Sr ratios (0.706–0.708), low and negative ɛ Nd (120 Ma) values (−6.6 to −9.0), and old Nd model ages (1.5–1.7 Ga) suggest that the rocks were probably formed by partial melting of the Paleoproterozoic granitic gneisses from the basement, with participation of depleted mantle in an extensional setting. Graphical Abstract Highlights ► FeO-, MnO-rich garnet crystallized at the expense of biotite from MnO-rich granitic magma. ► Granite formed from a highly evolved metaluminous A-type magma. ► Granite magma derived through the melting of Paleoproterozoic granitic gneisses.

Description: Publication year: 2012 Source: Geoscience Frontiers Sanghoon Kwon, Gautam Mitra The map expression of “abrupt” changes in lateral stratigraphic level of a thrust fault has been traditionally interpreted to be a result of the presence of (1) a lateral (or oblique) thrust-ramp, or (2) a frontal ramp with displacement gradient, and/or (3) a combination of these geometries. These geometries have been used to interpret the structures near transverse zones in fold-thrust belts (FTB). This contribution outlines an alternative explanation that can result in the same map pattern by lateral variations in stratigraphy along the strike of a low angle thrust fault. We describe the natural example of the Leamington transverse zone, which marks the southern margin of the Pennsylvanian–Permian Oquirrh basin with genetically related lateral stratigraphic variations in the North American Sevier FTB. Thus, the observed map pattern at this zone is closely related to lateral stratigraphic variations along the strike of a horizontal fault. Even though the present-day erosional level shows the map pattern that could be interpreted as a lateral ramp, the observed structures along the Leamington zone most likely share the effects of the presence of a lateral (or oblique) ramp, lateral stratigraphic variations along the fault trace, and the displacement gradient. Graphical Abstract Highlights ► Map expression of “abrupt” changes in lateral stratigraphic level of a thrust fault. ► New interpretation along a frontal-ramp without vertical-axis rotations. ► “Abrupt” changes controlled by lateral (or oblique) ramp, stratigraphy along a fault, and displacement gradients on a frontal ramp.

Description: Publication year: 2012 Source: Geoscience Frontiers Y. Srinivas, A. Stanley Raj, D.Hudson Oliver, D. Muthuraj, N. Chandrasekar The applications of intelligent techniques have increased exponentially in recent days to study most of the non-linear parameters. In particular, the behavior of earth resembles the non-linearity applications. An efficient tool is needed for the interpretation of geophysical parameters to study the subsurface of the earth. Artificial Neural Networks (ANN) perform certain tasks if the structure of the network is modified accordingly for the purpose it has been used. The three most robust networks were taken and comparatively analyzed for their performance to choose the appropriate network. The single-layer feed-forward neural network with the back propagation algorithm is chosen as one of the well-suited networks after comparing the results. Initially, certain synthetic data sets of all three-layer curves have been taken for training the network, and the network is validated by the field datasets collected from Tuticorin Coastal Region (78°7'30"E and 8°48'45"N), Tamil Nadu, India. The interpretation has been done successfully using the corresponding learning algorithm in the present study. With proper training of back propagation networks, it tends to give the resistivity and thickness of the subsurface layer model of the field resistivity data concerning the synthetic data trained earlier in the appropriate network. The network is trained with more Vertical Electrical Sounding (VES) data, and this trained network is demonstrated by the field data. Groundwater table depth also has been modeled. Graphical Abstract Highlights ► Vertical Electrical Sounding data in the Tuticorin region has been modeled for ground water occurrence and saline water intrusion. ► Artificial Neural Network program using Feed forward back propagation algorithm gains more advantage over conventional methods. ► Error percentage on comparing with the conventional method makes the program to extend on different type of field data. ► Synthetic Memory driven model forms the frame work of the algorithm to support any kind of rough field data. ► Saline water intrusion and ground water occurrence can be very well studied with well defined sub surface structural modeling.

Description: Publication year: 2012 Source: Geoscience Frontiers Dedong Li, Yuwang Wang, Jingbin Wang, Zhaohua Luo, Jiulong Zhou, Zongfeng Yang, Cui Liu According to the metallogenic theory by transmagmatic fluid (TMF), one magmatic intrusion is a channel of ore-bearing fluids, but not their source. Therefore, it is possible to use TMF’s ability for injection into and for escaping from the magmatic intrusion to evaluate its ore-forming potential. As the ore-bearing fluids cannot effectively inject into the magmatic intrusion when the magma fully crystallized, the cooling time and rates viscosity varied can be used to estimate the minimum critical thickness of the intrusion. One dimensional heat transfer model is used to determine the cooling time for three representative dikes of different composition (granite porphyry, quartz diorite and diabase) in the Shihu gold deposit. It is also estimated the rates viscosity varied in these time interval. We took the thickness of dike at the intersection of the cooling time – thickness curve and the rates viscosity varied versus thickness curve as the minimum critical thickness. For the ore-bearing fluids effectively injecting into the magma, the minimum critical thicknesses for the three representative dikes are 33.45 m for granite porphyry, 8.22 m for quartz diorite and 1.02 m for diabase, indicating that ore-bearing dikes must be thicker than each value. These results are consistent with the occurrence of ore bodies, and thus they could be applied in practice. Based on the statistical relationship between the length and the width of dikes, these critical thicknesses are used to compute critical areas: 0.0003–0.0016 km 2 for diabase, 0.014–0.068 km 2 for quartz diorite and 0.011–0.034 km 2 for granite porphyry. This implies that ore-bearing minor intrusions have varied areas corresponding to their composition. The numerical simulation has provided the theoretical threshold of exposed thickness and area of the ore-bearing intrusion. These values can be used to determine the ore-forming potentials of dikes. Graphical Abstract Highlights ► Heat transfer and viscosity models are used to determine cooling time and viscosity variation for dikes, respectively. ► Minimum critical thicknesses of three representative dikes for ore-bearing fluid injection are computed. ► Minimum critical areas of ore-bearing dikes are estimated in view of their ratios of length/ width.

Description: Publication year: 2011 Source: Geoscience Frontiers Wei Ju, Guiting Hou, Le Li, Fangfeng Xiao This paper presents the end Late Paleozoic tectonic stress field in the southern edge of Junggar Basin by interpreting stress-response structures (dykes, folds, faults with slickenside and conjugate joints). The direction of the maximum principal stress axes is interpreted to be NW–SE (about 325°), and the accommodated motion among plates is assigned as the driving force of this tectonic stress field. The average value of the stress index R ′ is about 2.09, which indicates a variation from strike-slip to compressive tectonic stress regime in the study area during the end Late Paleozoic period. The reconstruction of the tectonic field in the southern edge of Junggar Basin provides insights into the tectonic deformation processes around the southern Junggar Basin and contributes to the further understanding of basin evolution and tectonic settings during the culmination of the Paleozoic. Graphical Abstract Highlights ► The direction of the maximum principal stress axes is interpreted to be NW–SE. ► The stress regime is a variation from strike-slip to compressive. ► The accommodated motion among plates may be the cause of this stress field.

Description: Publication year: 2011 Source: Geoscience Frontiers Liu He, Chuanlun L. Zhang, Hailiang Dong, Bin Fang, Genhou Wang Isoprenoidal glycerol dialkyl glycerol tetraethers (iGDGTs) from the Gulu hot springs (23–83.6 °C, pH 〉 7) and Yangbajing hot springs (80–128 °C, pH 〉 7) were analyzed in order to investigate the distribution of archaeal lipids among different hot springs in Tibet. A soil sample from Gulu was incubated at different temperatures and analyzed for changes in iGDGTs to help evaluate whether surrounding soil may contribute to the iGDGTs in hot springs. The sources of bacterial GDGTs (bGDGTs) in these hot springs were also investigated. The results revealed different profiles of iGDGTs between Gulu and Yangbajing hot springs. Core iGDGTs and polar iGDGTs also presented different patterns in each hot spring. The PCA analysis showed that the structure of polar iGDGTs can be explained by three factors and suggested multiple sources of these compounds. Bivariate correlation analysis showed significant positive correlations between polar and core bGDGTs, suggesting the in situ production of bGDGTs in the hot springs. Furthermore, in the soil incubation experiment, temperature had the most significant influence on concentration of bGDGTs rather than iGDGTs, and polar bGDGTs had greater variability than core bGDGTs with changing temperature. Our results indicated that soil input had little influence on the composition of GDGTs in Tibetan hot springs. On the other hand, ring index and TEX 86 values were both positively correlated with incubation temperature, suggesting that the structure of archaeal lipids changed in response to varying temperature during incubation. Graphical Abstract Highlights ► Glycerol dialkyl glycerol tetraethers (GDGTs) are determined from Tibetan hot springs and soil. ► Archaeal and bacterial GDGTs are produced in situ in the hot spring. ► Soil incubation experiments show a positive correlation between ring index or TEX 86 and incubation temperature.

Description: On teaching styles of water educators and the impact of didactic training Hydrology and Earth System Sciences Discussions, 9, 2959-2986, 2012 Author(s): A. Pathirana, J. H. Koster, E. de Jong, and S. Uhlenbrook Solving today's complex hydrological problems requires originality, creative thinking and trans-disciplinary approaches. Hydrological education that was traditionally teacher centred, where the students look up to the teacher for expertise and information, should change to better prepare hydrologists to develop new knowledge and apply it in new contexts. An important first step towards this goal is to change the concept of education in the educators' minds. The results of an investigation to find out whether didactic training influences the beliefs of hydrology educators about their teaching styles is presented. Faculty of UNESCO-IHE has been offered a didactic certification program named University Teaching Qualification (UTQ). The hypothesis that UTQ training will significantly alter the teaching style of faculty at UNESCO-IHE from expert/formal authority traits towards facilitator/delegator traits was tested. A first survey was conducted among the entire teaching staff (total 101, response rate 58%). The results indicated that there are significantly higher traits of facilitator and delegator teaching styles among UTQ graduates compared to faculty who were not significantly trained in didactics. The second survey which was conducted among UTQ graduates (total 20, response rate 70%), enquiring after their teaching styles before and after UTQ, corroborated these findings.

Description: Characterization of deep aquifer dynamics using principal component analysis of sequential multilevel data Hydrology and Earth System Sciences, 16, 761-771, 2012 Author(s): D. Kurtzman, L. Netzer, N. Weisbrod, A. Nasser, E. R. Graber, and D. Ronen Two sequential multilevel profiles were obtained in an observation well opened to a 130-m thick, unconfined, contaminated aquifer in Tel Aviv, Israel. While the general profile characteristics of major ions, trace elements, and volatile organic compounds were maintained in the two sampling campaigns conducted 295 days apart, the vertical locations of high concentration gradients were shifted between the two profiles. Principal component analysis (PCA) of the chemical variables resulted in a first principal component which was responsible for ∼60% of the variability, and was highly correlated with depth. PCA revealed three distinct depth-dependent water bodies in both multilevel profiles, which were found to have shifted vertically between the sampling events. This shift cut across a clayey bed which separated the top and intermediate water bodies in the first profile, and was located entirely within the intermediate water body in the second profile. Continuous electrical conductivity monitoring in a packed-off section of the observation well revealed an event in which a distinct water body flowed through the monitored section ( v ∼ 150 m yr −1 ). It was concluded that the observed changes in the profiles result from dominantly lateral flow of water bodies in the aquifer rather than vertical flow. The significance of this study is twofold: (a) it demonstrates the utility of sequential multilevel observations from deep wells and the efficacy of PCA for evaluating the data; (b) the fact that distinct water bodies of 10 to 100 m vertical and horizontal dimensions flow under contaminated sites, which has implications for monitoring and remediation.

Description: Identifying the causes of differences in ozone production from the CB05 and CBMIV chemical mechanisms Geoscientific Model Development, 5, 257-268, 2012 Author(s): R. D. Saylor and A. F. Stein An investigation was conducted to identify the mechanistic differences between two versions of the carbon bond gas-phase chemical mechanism (CB05 and CBMIV) which consistently lead to larger ground-level ozone concentrations being produced in the CB05 version of the National Air Quality Forecasting Capability (NAQFC) modeling system even though the two parallel forecast systems utilize the same meteorology and base emissions and similar initial and boundary conditions. Box models of each of the mechanisms as they are implemented in the NAQFC were created and a set of 12 sensitivity simulations was designed. The sensitivity simulations independently probed the conceptual mechanistic differences between CB05 and CBMIV and were exercised over a 45-scenario simulation suite designed to emulate the wide range of chemical regimes encountered in a continental-scale atmospheric chemistry model. Results of the sensitivity simulations indicate that two sets of reactions that were included in the CB05 mechanism, but which were absent from the CBMIV mechanism, are the primary causes of the greater ozone production in the CB05 version of the NAQFC. One set of reactions recycles the higher organic peroxide species of CB05 (ROOH), resulting in additional photochemically reactive products that act to produce additional ozone in some chemical regimes. The other set of reactions recycles reactive nitrogen from less reactive forms back to NO 2 , increasing the effective NO x concentration of the system. In particular, the organic nitrate species (NTR), which was a terminal product for reactive nitrogen in the CBMIV mechanism, acts as a reservoir species in CB05 to redistribute NO x from major source areas to potentially NO x -sensitive areas where additional ozone may be produced in areas remote from direct NO x sources.

Description: The Nexus Land-Use model version 1.0, an approach articulating biophysical potentials and economic dynamics to model competition for land-use Geoscientific Model Development Discussions, 5, 571-638, 2012 Author(s): F. Souty, T. Brunelle, P. Dumas, B. Dorin, P. Ciais, R. Crassous, C. Müller, and A. Bondeau Interactions between food demand, biomass energy and forest preservation are driving both food prices and land-use changes, regionally and globally. This study presents a new model called Nexus Land-Use version 1.0 which describes these interactions through a generic representation of agricultural intensification mechanisms. The Nexus Land-Use model equations combine biophysics and economics into a single coherent framework to calculate crop yields, food prices, and resulting pasture and cropland areas within 12 regions inter-connected with each other by international trade. The representation of cropland and livestock production systems in each region relies on three components: (i) a biomass production function derived from the crop yield response function to inputs such as industrial fertilisers; (ii) a detailed representation of the livestock production system subdivided into an intensive and an extensive component, and (iii) a spatially explicit distribution of potential (maximal) crop yields prescribed from the Lund-Postdam-Jena global vegetation model for managed Land (LPJmL). The economic principles governing decisions about land-use and intensification are adapted from the Ricardian rent theory, assuming cost minimisation for farmers. The land-use modelling approach described in this paper entails several advantages. Firstly, it makes it possible to explore interactions among different types of biomass demand for food and animal feed, in a consistent approach, including indirect effects on land-use change resulting from international trade. Secondly, yield variations induced by the possible expansion of croplands on less suitable marginal lands are modelled by using regional land area distributions of potential yields, and a calculated boundary between intensive and extensive production. The model equations and parameter values are first described in details. Then, idealised scenarios exploring the impact of forest preservation policies or rising energy price on agricultural intensification are described, and their impacts on pasture and cropland areas are investigated.

Description: Editorial “Advances in Earth observation for water cycle science” Hydrology and Earth System Sciences, 16, 543-549, 2012 Author(s): D. Fernández-Prieto, P. van Oevelen, Z. Su, and W. Wagner

Description: Spiral structures and regularities in magnetic field variations and auroras History of Geo- and Space Sciences, 3, 1-31, 2012 Author(s): Y. I. Feldstein, L. I. Gromova, M. Förster, and A. E. Levitin The conception of spiral shaped precipitation regions, where solar corpuscles penetrate the upper atmosphere, was introduced into geophysics by C. Störmer and K. Birkeland at the beginning of the last century. Later, in the course of the XX-th century, spiral distributions were disclosed and studied in various geophysical phenomena. Most attention was devoted to spiral shapes in the analysis of regularities pertaining to the geomagnetic activity and auroras. We review the historical succession of perceptions about the number and positions of spiral shapes, that characterize the spatial-temporal distribution of magnetic disturbances. We describe the processes in the upper atmosphere, which are responsible for the appearance of spiral patterns. We considered the zones of maximal aurora frequency and of maximal particle precipitation intensity, as offered in the literature, in their connection with the spirals. We discuss the current system model, that is closely related to the spirals and that appears to be the source for geomagnetic field variations during magnetospheric substorms and storms. The currents in ionosphere and magnetosphere constitute together with field-aligned (along the geomagnetic field lines) currents (FACs) a common 3-D current system. At ionospheric heights, the westward and eastward electrojets represent characteristic elements of the current system. The westward electrojet covers the longitudinal range from the morning to the evening hours, while the eastward electrojet ranges from afternoon to near-midnight hours. The polar electrojet is positioned in the dayside sector at cusp latitudes. All these electrojets map along the magnetic field lines to certain plasma structures in the near-Earth space. The first spiral distribution of auroras was found based on observations in Antarctica for the nighttime-evening sector (N-spiral), and later in the nighttime-evening (N-spiral) and morning (M-spiral) sectors both in the Northern and Southern Hemispheres. The N- and M-spirals drawn in polar coordinates form an oval, along which one observes most often auroras in the zenith together with a westward electrojet. The nature of spiral distributions in geomagnetic field variations was unabmibuously interpreted after the discovery of the spiral's existence in the auroras had been established and this caused a change from the paradigm of the auroral zone to the paradigm of the auroral oval. Zenith forms of auroras are found within the boundaries of the auroral oval. The oval is therefore the region of most frequent precipitations of corpuscular fluxes with auroral energy, where anomalous geophysical phenomena occur most often and with maximum intensity. S. Chapman and L. Harang identified the existence of a discontinuity at auroral zone latitudes (Φ ∼ 67°) around midnight between the westward and eastward electrojets, that is now known as the Harang discontinuity. After the discovery of the auroral oval and the position of the westward electrojet along the oval, it turned out, that there is no discontinuity at a fixed latitude between the opposite electrojets, but rather a gap, the latitude of which varies smoothly between Φ ∼ 67° at midnight and Φ ∼ 73° at 20:00 MLT. In this respect the term ''Harang discontinuity'' represents no intrinsic phenomenon, because the westward electrojet does not experience any disruption in the midnight sector but continues without breaks from dawn to dusk hours.

Description: Observations of glyoxal and formaldehyde as metrics for the anthropogenic impact on rural photochemistry Atmospheric Chemistry and Physics Discussions, 12, 6049-6084, 2012 Author(s): J. P. DiGangi, S. B. Henry, A. Kammrath, E. S. Boyle, L. Kaser, R. Schnitzhofer, M. Graus, A. Turnipseed, J.-H. Park, R. J. Weber, R. S. Hornbrook, C. A. Cantrell, R. L. Maudlin III, S. Kim, Y. Nakashima, G. M. Wolfe, Y. Kajii, E. C. Apel, A. H. Goldstein, A. Guenther, T. Karl, A. Hansel, and F. N. Keutsch We present simultaneous fast, in-situ measurements of formaldehyde and glyoxal from two rural campaigns, BEARPEX 2009 and BEACHON-ROCS, both located in Pinus Ponderosa forests with emissions dominated by biogenic volatile organic compounds (VOCs). Despite considerable variability in the formaldehyde and glyoxal concentrations, the ratio of glyoxal to formaldehyde, R GF , displayed a very regular diurnal cycle over nearly 2 weeks of measurements. The only deviations in R GF were toward higher values and were the result of a biomass burning event during BEARPEX 2009 and very fresh anthropogenic influence during BEACHON-ROCS. Other rapid changes in glyoxal and formaldehyde concentrations have hardly any affect on R GF and could reflect transitions between low and high NO regimes. The trend of increased R GF from both anthropogenic reactive VOC mixtures and biomass burning compared to biogenic reactive VOC mixtures is robust due to the short timescales over which the observed changes in R GF occurred. Satellite retrievals, which suggest higher R GF for biogenic areas, are in contrast to our observed trends. It remains important to address this discrepancy, especially in view of the importance of satellite retrievals and in-situ measurements for model comparison. In addition, we propose that R GF , together with the absolute concentrations of glyoxal and formaldehyde, represents a useful metric for biogenic or anthropogenic reactive VOC mixtures. In particular, R GF yields information about not simply the VOCs in an airmass, but the VOC processing that directly couples ozone and secondary organic aerosol production.

Description: Characterization of aerosol and cloud water at a mountain site during WACS 2010: secondary organic aerosol formation through oxidative cloud processing Atmospheric Chemistry and Physics Discussions, 12, 6019-6047, 2012 Author(s): A. K. Y. Lee, K. L. Hayden, P. Herckes, W. R. Leaitch, J. Liggio, A. M. Macdonald, and J. P. D. Abbatt The water-soluble fractions of aerosol samples and cloud water collected during Whistler Aerosol and Cloud Study (WACS 2010) were analyzed using an Aerodyne aerosol mass spectrometer (AMS). This is the first study to report AMS organic spectra of re-aerosolized cloud water, and to make direct comparison between the AMS spectra of cloud water and aerosol samples collected at the same location. In general, the aerosol and cloud organic spectra were very similar, indicating that the cloud water organics likely originated from secondary organic aerosol (SOA) formed nearby. By using a photochemical reactor to oxidize both aerosol filter extracts and cloud water, we find evidence that fragmentation of aerosol water-soluble organics increases their volatility during oxidation. By contrast, enhancement of AMS-measurable organic mass by up to 30% was observed during aqueous-phase photochemical oxidation of cloud water organics. We propose that additional SOA material was produced by functionalizing dissolved organics via OH oxidation, where these dissolved organics are sufficiently volatile that they are not usually part of the aerosol. This work points out that water-soluble organic compounds of intermediate volatility (IVOC), such as cis -pinonic acid, produced via gas-phase oxidation of monoterpenes, can be important aqueous-phase SOA precursors in a biogenic-rich environment.

Description: Evaluation of Arctic broadband surface radiation measurements Atmospheric Measurement Techniques, 5, 429-438, 2012 Author(s): N. Matsui, C. N. Long, J. Augustine, D. Halliwell, T. Uttal, D. Longenecker, O. Niebergall, J. Wendell, and R. Albee The Arctic is a challenging environment for making in-situ surface radiation measurements. A standard suite of radiation sensors is typically designed to measure incoming and outgoing shortwave (SW) and thermal infrared, or longwave (LW), radiation. Enhancements may include various sensors for measuring irradiance in narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that keep sensors and shading devices trained on the sun along its diurnal path. High quality measurements require striking a balance between locating stations in a pristine undisturbed setting free of artificial blockage (such as from buildings and towers) and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data in the Arctic include solar tracker malfunctions, rime/frost/snow deposition on the protective glass domes of the radiometers and operational problems due to limited operator access in extreme weather conditions. In this study, comparisons are made between the global and component sum (direct [vertical component] + diffuse) SW measurements. The difference between these two quantities (that theoretically should be zero) is used to illustrate the magnitude and seasonality of arctic radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both SW and LW measurements. Solutions to these operational problems that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols are proposed.

Description: Evaluation of chemical transport model predictions of primary organic aerosol for air masses classified by particle-component-based factor analysis Atmospheric Chemistry and Physics Discussions, 12, 5939-6018, 2012 Author(s): C. A. Stroud, M. D. Moran, P. A. Makar, S. Gong, W. Gong, J. Zhang, J. G. Slowik, J. P. D. Abbatt, G. Lu, J. R. Brook, C. Mihele, Q. Li, D. Sills, K. B. Strawbridge, M. L. McGuire, and G. J. Evans Observations from the 2007 Border Air Quality and Meteorology Study (BAQS-Met 2007) in southern Ontario (ON), Canada, were used to evaluate Environment Canada's regional chemical transport model predictions of primary organic aerosol (POA). Environment Canada's operational numerical weather prediction model and the 2006 Canadian and 2005 US national emissions inventories were used as input to the chemical transport model (named AURAMS). Particle-component-based factor analysis was applied to aerosol mass spectrometer measurements made at one urban site (Windsor, ON) and two rural sites (Harrow and Bear Creek, ON) to derive hydrocarbon-like organic aerosol (HOA) factors. Co-located carbon monoxide (CO), PM 2.5 black carbon (BC), and PM 1 SO 4 measurements were also used for evaluation and interpretation, permitting a detailed diagnostic model evaluation. At the urban site, good agreement was observed for the comparison of daytime campaign PM 1 POA and HOA mean values: 1.1 μg m −3 vs. 1.2 μg m −3 , respectively. However, a POA overprediction was evident on calm nights due to an overly-stable model surface layer. Biases in model POA predictions trended from positive to negative with increasing HOA values. This trend has several possible explanations, including (1) underweighting of urban locations in particulate matter (PM) spatial surrogate fields, (2) overly-coarse model grid spacing for resolving urban-scale sources, and (3) lack of a model particle POA evaporation process during dilution of vehicular POA tail-pipe emissions to urban scales. Furthermore, a trend in POA bias was observed at the urban site as a function of the BC/HOA ratio, suggesting a possible association of POA underprediction for diesel combustion sources. For several time periods, POA overprediction was also observed for sulphate-rich plumes, suggesting that our model POA fractions for the PM 2.5 chemical speciation profiles may be too high for these point sources. At the rural Harrow site, significant underpredictions in PM 1 POA concentration were found compared to observed HOA concentration and were associated, based on back-trajectory analysis, with (1) transport from the Detroit/Windsor urban complex, (2) longer-range transport from the US Midwest, and (3) biomass burning. Daytime CO concentrations were significantly overpredicted at Windsor but were unbiased at Harrow. Collectively, these biases provide support for a hypothesis that combines a current underweighting of PM spatial surrogate fields for urban locations with insufficient model vertical mixing for sources close to the urban measurement sites. The magnitude of the area POA emissions sources in the US and Canadian inventories (e.g., food cooking, road and soil dust, waste disposal burning) suggests that more effort should be placed at reducing uncertainties in these sectors, especially spatial and temporal surrogates.

Description: Direct observations of diel biological CO 2 fixation in the oceans Biogeosciences Discussions, 9, 2153-2168, 2012 Author(s): H. Thomas, S. E. Craig, B. J. W. Greenan, W. Burt, G. J. Herndl, S. Higginson, L. Salt, E. H. Shadwick, and J. Urrego-Blanco Much of the variability in the surface ocean's carbon cycle can be attributed to the availability of sunlight, through processes such as heat fluxes and photosynthesis, which regulate over a wide range of time scales. The critical processes occurring on timescales of a day or less, however, have undergone few investigations, and most of these have been limited to a time span of several days to months, or exceptionally, for longer periods. Optical methods have helped to infer short-term biological variability, however corresponding investigations of the oceanic CO 2 system are lacking. We employ high-frequency CO 2 and optical observations covering the full seasonal cycle on the Scotian Shelf, Northwestern Atlantic Ocean, in order to unravel diel periodicity of the surface ocean carbon cycle and its effects on annual budgets. Significant diel periodicity occurs only if the water column is sufficiently stable as observed during seasonal warming. During that time biological CO 2 drawdown, or net community production (NCP), is delayed for several hours relative to the onset of photosynthetically available radiation (PAR), due to diel cycles in chlorophyll- a concentration and to grazing, both of which, we suggest, inhibit NCP in the early morning hours. In summer, NCP decreases by more than 90 %, coinciding with the seasonal minimum of the mixed layer depth and resulting in the disappearance of the diel CO 2 periodicity in the surface waters.

Description: Publication year: 2012 Source: Geoscience Frontiers, Volume 3, Issue 2, March 2012, Pages I-II [No author name available]

Description: Solar wind and geomagnetism: toward a standard classification of geomagnetic activity from 1868 to 2009 Annales Geophysicae, 30, 421-426, 2012 Author(s): J. L. Zerbo, C. Amory Mazaudier, F. Ouattara, and J. D. Richardson We examined solar activity with a large series of geomagnetic data from 1868 to 2009. We have revisited the geomagnetic activity classification scheme of Legrand and Simon (1989) and improve their scheme by lowering the minimum Aa index value for shock and recurrent activity from 40 to 20 nT. This improved scheme allows us to clearly classify about 80% of the geomagnetic activity in this time period instead of only 60% for the previous Legrand and Simon classification.

Description: A statistical study of the performance of the Hakamada-Akasofu-Fry version 2 numerical model in predicting solar shock arrival times at Earth during different phases of solar cycle 23 Annales Geophysicae, 30, 405-419, 2012 Author(s): S. M. P. McKenna-Lawlor, C. D. Fry, M. Dryer, D. Heynderickx, K. Kecskemety, K. Kudela, and J. Balaz The performance of the Hakamada Akasofu-Fry, version 2 (HAFv.2) numerical model, which provides predictions of solar shock arrival times at Earth, was subjected to a statistical study to investigate those solar/interplanetary circumstances under which the model performed well/poorly during key phases (rise/maximum/decay) of solar cycle 23. In addition to analyzing elements of the overall data set (584 selected events) associated with particular cycle phases, subsets were formed such that those events making up a particular sub-set showed common characteristics. The statistical significance of the results obtained using the various sets/subsets was generally very low and these results were not significant as compared with the hit by chance rate (50%). This implies a low level of confidence in the predictions of the model with no compelling result encouraging its use. However, the data suggested that the success rates of HAFv.2 were higher when the background solar wind speed at the time of shock initiation was relatively fast. Thus, in scenarios where the background solar wind speed is elevated and the calculated success rate significantly exceeds the rate by chance, the forecasts could provide potential value to the customer. With the composite statistics available for solar cycle 23, the calculated success rate at high solar wind speed, although clearly above 50%, was indicative rather than conclusive. The RMS error estimated for shock arrival times for every cycle phase and for the composite sample was in each case significantly better than would be expected for a random data set. Also, the parameter "Probability of Detection, yes" (PODy) which presents the Proportion of Yes observations that were correctly forecast (i.e. the ratio between the shocks correctly predicted and all the shocks observed), yielded values for the rise/maximum/decay phases of the cycle and using the composite sample of 0.85, 0.64, 0.79 and 0.77, respectively. The statistical results obtained through detailed analysis of the available data provided insights into how changing circumstances on the Sun and in interplanetary space can affect the performance of the model. Since shock arrival predictions are widely utilized in making commercially significant decisions re. protecting space assets, the present detailed archival studies can be useful in future operational decision making during solar cycle 24. It would be of added value in this context to use Briggs-Rupert methodology to estimate the cost to an operator of acting on an incorrect forecast.

Description: Publication year: 2012 Source: Procedia Environmental Sciences, Volume 13 Makoto Ooba, Tsuyoshi Fujita, Motoyuki Mizuochi, Shogo Murakami, Qinxue Wang, Kunio Kohata Forest ecosystem services (ES), including water resources, carbon sequestration, nitrogen absorption, timber production, and sediment production in the Ise Bay basin, were estimated using a process-based biogeochemical forest model (the BGC-ES model and the RUSLE). This model was proposed and studied in the Yahagi river basin by some of the authors. To evaluate the ES on a 5-km-mesh scale, simulations from 1960 to 2040 were carried out under the following scenarios: an artificial forest under standard management (FM) and under forest management abounded from 1990 (AFM). Forest management practices strongly affected carbon sequestration and timber volume compared to other ES related to forest area.

Description: Extension of an assessment model of ship traffic exhaust emissions for particulate matter and carbon monoxide Atmospheric Chemistry and Physics, 12, 2641-2659, 2012 Author(s): J.-P. Jalkanen, L. Johansson, J. Kukkonen, A. Brink, J. Kalli, and T. Stipa A method is presented for the evaluation of the exhaust emissions of marine traffic, based on the messages provided by the Automatic Identification System (AIS), which enable the positioning of ship emissions with a high spatial resolution (typically a few tens of metres). The model also takes into account the detailed technical data of each individual vessel. The previously developed model was applicable for evaluating the emissions of NO x , SO x and CO 2 . This paper addresses a substantial extension of the modelling system, to allow also for the mass-based emissions of particulate matter (PM) and carbon monoxide (CO). The presented Ship Traffic Emissions Assessment Model (STEAM2) allows for the influences of accurate travel routes and ship speed, engine load, fuel sulphur content, multiengine setups, abatement methods and waves. We address in particular the modeling of the influence on the emissions of both engine load and the sulphur content of the fuel. The presented methodology can be used to evaluate the total PM emissions, and those of organic carbon, elemental carbon, ash and hydrated sulphate. We have evaluated the performance of the extended model against available experimental data on engine power, fuel consumption and the composition-resolved emissions of PM. We have also compared the annually averaged emission values with those of the corresponding EMEP inventory, As example results, the geographical distributions of the emissions of PM and CO are presented for the marine regions of the Baltic Sea surrounding the Danish Straits.

Description: The sudden stratospheric warming of the Arctic winter 2009/2010: comparison to other recent warm winters Atmospheric Chemistry and Physics Discussions, 12, 7243-7271, 2012 Author(s): J. Kuttippurath and G. Nikulin The Arctic winter 2009/10 was moderately cold in December. A minor warming occurred around mid-December due to a wave 2 amplification split the lower stratospheric vortex into two lobes. The vortices merged again and formed a relatively large vortex in a few days. The temperatures began to rise by mid-January and triggered a major sudden stratospheric warming (SSW) by the reversal of westerlies in late (24–26) January, driven by a planetary wave 1 with a peak amplitude of about 100 m 2 s −2 at 60° N/10 hPa. The momentum flux associated with this warming showed the largest value in the recent winters, about 450 m 2 s −2 at 60° N/10 hPa. The associated vortex split confined to altitudes below 10 hPa and hence, the major warming (MW) was a vortex displacement event. Large amounts of Eliassen-Palm (EP) and wave 2 EP fluxes (3.9 ×10 5 kg s −2 ) are found shortly before the MW event at 100 hPa over 45–75° N, suggesting a tropospheric preconditioning of the MW event. We observe an increase in SSWs in the Arctic in recent years, as there were 6 MWs in 6 out of the 7 winters of 2003/04–2009/10, which confirms the conclusions of previous studies on the SSWs in winters prior to 2003/04. Each MW event was unique as far as its evolution and related polar processes were concerned. As compared to the MWs in the recent Arctic winters, the strongest MW was observed in 2008/09 and was initiated by a wave 2 event. A detailed diagnosis of ozone loss during the past fifteen years shows that the loss is inversely proportional to the intensity and timing of SSWs in each winter, where early MWs lead to minimal loss. The ozone loss shows a good correlation with the zonal mean amplitude of zonal winds in January over 60–90° N, suggesting a proxy for MWs in the Arctic winters.

Description: Observing the continental-scale carbon balance: assessment of sampling complementarity and redundancy in a terrestrial assimilation system by means of quantitative network design Atmospheric Chemistry and Physics Discussions, 12, 7211-7242, 2012 Author(s): T. Kaminski, P. J. Rayner, M. Voßbeck, M. Scholze, and E. Koffi This paper investigates the relationship between the heterogeneity of the terrestrial carbon cycle and the optimal design of observing networks to constrain it. We combine the methods of quantitative network design and carbon-cycle data assimilation to a hierarchy of increasingly heterogeneous descriptions of the European terrestrial biosphere as indicated by increasing diversity of plant functional types. We employ three types of observations, flask measurements of CO 2 concentrations, continuous measurements of CO 2 and pointwise measurements of CO 2 flux. We show that flux measurements are extremely efficient for relatively homogeneous situations but not robust against increasing or unknown complexity. Here a hybrid approach is necessary and we recommend its use in the development of integrated carbon observing systems.

Description: Publication year: 2012 Source: Procedia Environmental Sciences, Volume 13 Wei Dong, Jianmin Shu, Ping He, Guangwen Ma, Ming Dong Wetland ecosystem occupies an important position in the global carbon cycle with a strong ability of carbon storage and fixation. On the basis of field investigation and laboratory measurement, in the paper, the standing biomass and primary production of wetland Phragmites australis in Baiyangdian were study, and its ability of carbon storage and fixation in accordance with the principle of photosynthesis was measured, and then the potential ability of carbon storage from the perspective of efficiency for solar energy utilization was discussed. The results show that carbon storage of wetland Phragmites australis is large in Baiyangdian with 5.81 kg • m -2 , 7.14 kg • m -2 and 8.72 kg • m -2 respectively; carbon fixation is also very large with 2.54 kg • m -2 , 3.12 kg • m -2 and 3.81 kg • m -2 respectively. In addition, the underground biomass is larger than the aboveground biomass, and the ratio of the two is 2.38-3.30 with the average of 2.90. The underground carbon storage is nearly 3 times as much as the aboveground carbon storage. Wetland Phragmites australis in Baiyangdian has a strong ability of carbon fixation with 1.17 kg • m -2 • a -1 , 1.49 kg • m -2 • a-1 and 1.76 kg • m -2 • a-1 respectively, which is 1.7-3.4 times as much as the average ability of carbon fixation of the national terrestrial plants and 2.0- 4.0 times of that of the global plants.

Description: Publication year: 2012 Source: Procedia Environmental Sciences, Volume 13 Rasoul Ghorbani, Ahad Ebrahimpour, Somayeh Noshad Most of the recreational places in Iran have constructed based on physical principles with less attention to user's mental and behavioral needs. Whereas these needs effect on increasing the number of users of these places; in this paper we attempt to analysis the motivation of users with Seeking-escaping and Pull and Push theory. At first we survey the people's principle motive of using the nature of Oun-Ebn-Ali recreational place with these models and then, the relationships between perceived emotions as intermediary and improved the quality of life as final reward, have evaluated. The results show that, the users go to Oun-Ebn-Ali natural place for escaping from pressure of everyday life and to achieving peace, watching the nature, doing sport and meeting friends. Although some undesirable factors such as shortage of trees shade and street furniture, congestion and unsuitable accessibility, influence the process of using recreational places and restrict the number of users. According to results, increasing natural attractions, recreational furniture, good accessibility and distribution of furniture in different parts of the site, will increase the desirability of using Oun-Ebn-Ali recreational place.

Description: Publication year: 2012 Source: Procedia Environmental Sciences, Volume 13 Madhumita Roy, Santanu Ray, Phani Bhusan Ghosh Decomposition and subsequent remineralization of mangrove detritus is important in nutrient dynamics within the forest as well as in offshore system. In order to study the impact of detritivorous fish on the mangrove estuarine detritus food web, a five compartment model of detritus food web dynamics has been developed for mangrove estuarine creeks of Hooghly- Matla Estuarine complex, Sundarban. The model simulates concentration of nutrient, biomass of phytoplankton, zooplankton, detritus and detritivorous fishes. Almost 70% of the detritus formed in the soil was being washed in the estuarine water to act as source or sink of nutrient for the primary producers of aquatic food chain. A significant amount of detritus in the estuarine water is readily consumed by a group of detritivorous fishes before it is being rematerialized completely in to inorganic nutrient form. The model has been calibrated and validated using field data accordingly. Increased detrital nitrogen values in the late monsoon and post monsoon months, assists the growth and high yield of detritivorous fishes as found in simulated and field observations. Comparison of simulated and observed results demonstrates the dependence of phytoplankton growth is a function of nutrient concentration and zooplankton grazing. Model results also show the dependence of detritivorous fishes on detritus which is a function of detritus biomass. In turn, detritus biomass is dependent upon several factors like mortality of phytoplankton, zooplankton, and detritivorous fishes; and chiefly on litter biomass and litter decomposition.

Description: Publication year: 2012 Source: Procedia Environmental Sciences, Volume 13 S.I. Bartsev Uniqueness which is inherent to an ecological system leads to situation when necessary requirement of science research - the reproducibility of an experiment - can not be fully satisfied when ecological systems are studied. A possible solution to the problem of experiment reproducibility and transfering obtained results to other ecosystems is developing some formal procedures for establishing a relationship of similarity (scaling) between models of ecosystems. Based on the concept of functional symmetry and Lie groups of continuous transformations a procedure for constructing ecosystem models, which are similar with respect to selected indicator is suggested. Applicability of this procedure to detecting similarities and to reducing complexity of ecosystem models is illustrated.

Description: Publication year: 2012 Source: Procedia Environmental Sciences, Volume 13 Joyita Mukherjee, Santanu Ray Carbon cycle has a fundamental role in changing climate of the earth. Recent models of the estuary-atmosphere system demonstrate the potentially great importance of estuarine environment to the regulation of atmospheric carbon dioxide. Carbon, the key element of life is available in organic and inorganic forms as different compounds in air, water and soil. Our study site, Hooghly - Matla estuarine system receives a large load of nutrients throughout the year. This is mainly due to high litterfall from the adjacent luxuriant mangroves and yield of huge suspended sediment carried along with the river Ganges which is flowing through the western part of the Sundarban mangrove ecosystem.Keeping in view the crucial role of carbon, a seven compartment model has been proposed to study the dynamics of carbon in this estuarine system. Different forms of carbon present in soil (as soil organic carbon (SOC), soil inorganic carbon (SIC)) and in water (as dissolved inorganic carbon (DIC), dissolved carbon dioxide (DCO2), dissolved bicarbonate (DBC), dissolved organic carbon (DOC) and particulate organic carbon (POC)) are taken as state variables. Litter biomass, dissolved oxygen, primary productivity, community respiration, temperature of water, pH of water, pH of soil, air-water exchange of carbon dioxide and conversion rates among different forms of carbon are considered as graph time functions. The data used in the present model are collected for over two years from our field works and experiments. Other sensitive rate parameters which are not possible to collect from survey or experiment, calibrated following standard procedure. Sensitivity analysis is performed along with calibration. Model simulation results are validated with observed data. Results show seasonal variations of litterfall and which is the main source of SOC pool and ultimately transported to the estuary. Other than litterfall, death of organisms in soil and water enriches the SOC and POC respectively. pH of water is governing factor and depending on this factor, DIC is converted to DCO2 and DBC, which are taken up by phytoplankton during photosynthesis. Mineralization rate of SOC to SIC and uptake rate of DCO2 and DBC are the sensitive parameters.

Description: Publication year: 2012 Source: Procedia Environmental Sciences, Volume 13 A.S. Komarov, Yu.S. Khoraskina, S.S. Bykhovets, M.G. Bezrukova Soil organic matter (SOM) dynamics is an important pool in biological turnover of carbon and other elements of plants nutrition in forest ecosystems. Problems at its modelling are: quantification of SOM fractions which are decomposing with specific rates; description of humification, obtaining dependencies of SOM rates of transformation in dependence on external factors. Different methods of fractionating of SOM are now in use based on different solubility of fractions/ This approach presents difficulties at model's initialization. We expanded a model of SOM dynamics ROMUL based on successive stages of mineralization and transformation of fresh litter, which correspond to SOM pools in horizons L, F and H of forest floor. A1 et al. are horizons in mineral soil. Rates of transformation of one SOM pool into another in these horizons can be obtained from experimental data. The dynamics of N, Ca and Mg is described using main equations of SOM transformations with inserting of additional constants or functions as independent multipliers for rates of transformation. Pools of elements available for plants nutrition, and some intermediate pools such as secondary soil minerals have been added to the model. New ROMUL has been successfully applied to ICP Forest plots in Russia.

Description: Publication year: 2012 Source: Procedia Environmental Sciences, Volume 13 Yang Zhang, Chen Yiyun, Ding Qing, Ping Jiang Urban heat island effect has obtained more and more attention because environmental problems caused by the urban heat island have affected people's normal life. In this paper, qualitative and quantitative analyses have been used to study the relationship between normalized difference vegetated index (NDVI) and surface radiation temperature. The relationship of NDVI and surface radiation temperature has been studied in spatial profile. On that basis, the paper has studied the spatial distribution of heat island in Wuhan city and explained the features of the Wuhan spatial distribution of heat island. Research results has showed that there is obvious negative correlation between NDVI and the surface radiation Heating island strength is higher in industrial and commercial areas than others; Water and green space perform a distinct role to divide and mitigate the heat island effect.

Description: Publication year: 2012 Source: Procedia Environmental Sciences, Volume 13 Narouchit Dampin, Wit Tarnchalanukit, Kasem Chunkao, Montri Maleewong The bioenergetics fish growth model of Nile Tilapia ( Oreochromis niloticus ) cultured in the cages in wastewater oxidation pond is presented. The oxidation pond is located in the very successful project area “The Leam Phak Bia Environmental Study Research and Development Project under Royal Initiatives Petchaburi Province” in Thailand. There are five oxidation ponds connected in series in the research area. The measurement of Nile tilapia growth is taken in the third pond in which the water quality is in the effluent standard. The water quality and fish weight are measured in each month for one year period. The fish growth model in the form of ordinary differential equation is introduced to understand the behavior of fish growth due to various environmental factors which are dissolved oxygen demand (DO), water temperature, concentration of plankton, ammonia and biochemical oxygen demand (BOD). In this presented model, we have introduced a new form of food assimilation efficiency as a function of fish weight. It is found that the predicted fish weight obtained from the model is in good agreement with the measurements. Also, this presented model can be applied to predict the fish weight in a wastewater stabilization pond when environmental factors have been changed.

Description: Publication year: 2012 Source: Procedia Environmental Sciences, Volume 13 C.Q. Yan, T.X. Yue, G. Zhao High Accuracy Surface Modelling (HASM) can model surface with high accuracy, while its speed is a major limitation for its application in large scale data. This paper presents HASM-GA, a Graphic Processor Unit (GPU) accelerated High Accuracy Surface Modelling, to construct surface with a significant boost performance. Modern GPU has a highly parallel architecture with hundreds ofprocessors and stream processors, which is a powerful tool for bothgraphics processing and general purpose computation. Weparallel the most computationally-intensive portion of the HASM through NVIDA'sCompute Unified Development Architecture(CUDA)andQuadro 2000 GPU. The results show that one order of magnitude speedupcan be achieved by fully using the parallel processing power of theGPU compared with the traditional CPU method.

Description: Publication year: 2012 Source: Procedia Environmental Sciences, Volume 13 L. Wu, Q. Jiang, X.M. Yang Eco-city planning has been a prevailing concern throughout China and beyond over the past few decades. Least-cost planning is a life-cycle costing approach for alternative analysis and decision-making, determining the preferred option that provides the optimal mix of financial, social and environmental outcomes for stakeholders throughout the project lifespan. A more sustainable approach is to incorporate the low carbon context into this economic analysis. Case studies, Tianjin Eco-city and Ningbo-Cixi Wetland Centre, granted by GEF, are presented and reviewed on how to foster key coastal areas of China into eco-cities by means of carbon footprint and costing. It is demonstrated that consideration should include carbon impact, carbon costs and accounting processes in the planning and management of the relevant plots, with achievement of key performance indicators relating to greenhouse gasses. Tertiary wastewater treatment, the selection of low carbon emission technology, and the utilization of constructed wetland configurations, green buildings and facilities are particularly demonstrated and modelled, employing energy software and economics tools repectively.

Description: Millennial-length forward models and pseudoproxies of stalagmite δ 18 O: an example from NW Scotland Climate of the Past Discussions, 8, 869-907, 2012 Author(s): A. Baker, C. Bradley, S. J. Phipps, M. Fischer, I. J. Fairchild, L. Fuller, C. Spötl, and C. Azcurra The stable oxygen isotope parameter δ 18 O remains the most widely utilised speleothem proxy for past climate reconstructions. Uncertainty can be introduced into stalagmite δ 18 O from a number of factors, one of which is the heterogeneity of groundwater flow in karstified aquifers. Here, we present a lumped parameter hydrological model, KarstFor, which is capable of generating monthly simulations of surface water – ground water – stalagmite δ 18 O for more than thousand year time periods. Using a variety of climate input series, we use this model for the first time to compare observational with modelled (pseudoproxy) stalagmite δ 18 O series for a site at Assynt, NW Scotland, where our knowledge of δ 18 O systematics is relatively well understood. The use of forward modelling allows us to quantify the relative contributions of climate, peat and karst hydrology, and disequilibrium effects in stalagmite δ 18 O, from which we can identify potential stalagmite δ 18 O responses to climate variability. Comparison of the modelled and actual stalagmite δ 18 O for two stalagmites from the site demonstrates that for the period of overlapping growth, the two series do not correlate with one another, but forward modelling demonstrates that this falls within the range explicable by differences in flow routing to the stalagmites. Pseudoproxy δ 18 O stalagmite series highlight the potential significance of peat hydrology in controlling stalagmite δ 18 O over the last 1000 years at this site.

Description: Reconstruction of high resolution atmospheric fields for Northern Europe using analog-upscaling Climate of the Past Discussions, 8, 819-868, 2012 Author(s): F. Schenk and E. Zorita The analog method (AM) has found application to reconstruct gridded climate fields from the information provided by proxy data and climate model simulations. Here, we test the skill of different set-ups of the AM, in a controlled but realistic situation, by analysing several statistical properties of reconstructed daily high-resolution atmospheric fields for Northern Europe for a 50-year period. In this application, station observations of sea-level pressure and air temperature are combined with atmospheric fields from a 50-year high-resolution regional climate simulation. This reconstruction aims at providing homogeneous and physically consistent atmospheric fields with daily resolution suitable to drive high resolution ocean and ecosystem models. Different settings of the AM are evaluated in this study for the period 1958-2007 to estimate the robustness of the reconstruction and its ability to replicate high and low-frequent variability, realistic probability distributions and extremes of different meteorological variables. It is shown that the AM can realistically reconstruct variables with a strong physical link to daily sea-level pressure on daily and monthly scale. However, to reconstruct low-frequency decadal and longer temperature variations, additional monthly mean station temperature as predictor is required. Our results suggest that the AM is a suitable upscaling tool to predict daily fields taken from regional climate simulations based on sparse historical station data. After this testing and characterization of the different set-ups the method will be applied to reconstruct the high-resolution atmospheric fields for the last 160 years.

Description: Madagascar corals reveal Pacific multidecadal modulation of rainfall since 1708 Climate of the Past Discussions, 8, 787-817, 2012 Author(s): C. A. Grove, J. Zinke, F. Peeters, W. Park, T. Scheufen, S. Kasper, B. Randriamanantsoa, M. T. McCulloch, and G.-J. A. Brummer The Pacific Ocean modulates Australian and North American rainfall variability on multidecadal timescales, in concert with the Pacific Decadal Oscillation (PDO). It has been suggested that Pacific decadal variability may also influence Indian Ocean surface temperature and rainfall in a far-field response, similar to the El Niño Southern Oscillation (ENSO) on interannual timescales. However, instrumental records of rainfall are too short and too sparse to confidently assess such multidecadal climatic teleconnections. Here, we present four climate archives spanning the past 300 yr from giant Madagascar corals. We decouple 20th century human deforestation effects from rainfall induced soil erosion using spectral luminescence scanning and geochemistry. The corals provide the first evidence for Pacific decadal modulation of rainfall over the Western Indian Ocean. We find that positive PDO phases are associated with increased Indian Ocean temperatures and rainfall in Eastern Madagascar, while precipitation in Southern Africa and Eastern Australia declines. Consequently, the negative PDO phase that started in 1998 should lead to reduced rainfall over Eastern Madagascar and increased precipitation in Southern Africa and Eastern Australia. We conclude that the PDO has important implications for future multidecadal variability of African rainfall, where water resource management is increasingly important under the warming climate.

Description: The regulation of the air: a hypothesis Solid Earth, 3, 87-96, 2012 Author(s): E. G. Nisbet, C. M. R. Fowler, and R. E. R. Nisbet We propose the hypothesis that natural selection, acting on the specificity or preference for CO 2 over O 2 of the enzyme rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase), has controlled the CO 2 :O 2 ratio of the atmosphere since the evolution of photosynthesis and has also sustained the Earth's greenhouse-set surface temperature. Rubisco works in partnership with the nitrogen-fixing enzyme nitrogenase to control atmospheric pressure. Together, these two enzymes control global surface temperature and indirectly the pH and oxygenation of the ocean. Thus, the co-evolution of these two enzymes may have produced clement conditions on the Earth's surface, allowing life to be sustained.

Description: Modelling sub-grid wetland in the ORCHIDEE global land surface model: evaluation against river discharges and remotely sensed data Geoscientific Model Development Discussions, 5, 683-735, 2012 Author(s): B. Ringeval, B. Decharme, S. L. Piao, P. Ciais, F. Papa, N. de Noblet-Ducoudré, C. Prigent, P. Friedlingstein, I. Gouttevin, C. Koven, and A. Ducharne The quality of the global hydrological simulations performed by Land Surface Models (LSMs) strongly depends on processes that occur at unresolved spatial scales. Approaches such as TOPMODEL have been developed, which allow soil moisture redistribution within each grid-cell, based upon sub-grid scale topography. Moreover, the coupling between TOPMODEL and a LSM appears as a potential way to simulate wetland extent dynamic and its sensitivity to climate, a recently identified research problem for biogeochemical modelling, including methane emissions. Global evaluation of the coupling between TOPMODEL and an LSM is difficult, and prior attempts have been indirect, based on the evaluation of the simulated river flow. This study presents a new way to evaluate this coupling, within the ORCHIDEE LSM, using remote sensing data of inundated areas. Because of differences in nature between the satellite derived information – inundation extent – and the variable diagnosed by TOPMODEL/ORCHIDEE – area at maximum soil water content –, the evaluation focuses on the spatial distribution of these two quantities as well as on their temporal variation. Despite some difficulties in exactly matching observed localized inundated events, we obtain a rather good agreement in the distribution of these two quantities at a global scale. Floodplains are not accounted for in the model, and this is a major limitation. The difficulty of reproducing the year-to-year variability of the observed inundated area (for instance, the decreasing trend by the end of 90s) is also underlined. Classical indirect evaluation based on comparison between simulated and observed riverflow is also performed and underlines difficulties to simulate riverflow after coupling with TOPMODEL. The relationship between inundation and river flow at the basin scale in the model is analyzed, using both methods (evaluation against remote sensing data and riverflow). Finally, we discuss the potential of the TOPMODEL/LSM coupling to simulate wetland areas. A major limitation of the coupling for this purpose is linked to its ability to simulate a global wetland coverage consistent with the commonly used datasets. However, it seems to be a good opportunity to account for the wetland areas sensitivity to the climate and thus to simulate its temporal variability.

Description: River monitoring from satellite radar altimetry in the Zambezi River Basin Hydrology and Earth System Sciences Discussions, 9, 3203-3235, 2012 Author(s): C. I. Michailovsky, S. McEnnis, P. A. M. Berry, R. Smith, and P. Bauer-Gottwein Satellite radar altimetry can be used to monitor surface water levels from space. While current and past altimetry missions were designed to study oceans, retracking the waveforms returned over land allows data to be retrieved for smaller water bodies or narrow rivers. In this study, retracked Envisat altimetry data was extracted over the Zambezi River Basin using a detailed river mask based on Landsat imagery. This allowed for stage measurements to be obtained for rivers down to 80 m wide with an RMSE relative to in situ levels of 0.32 to 0.72 m at different locations. The altimetric levels were then converted to discharge using three different methods adapted to different data-availability scenarios: first with an in situ rating curve available, secondly with one simultaneous field measurement of cross-section and discharge, and finally with only historical discharge data available. For the two locations at which all three methods could be applied the accuracies of the different methods were found to be comparable, with RMSE values ranging from 5.5 to 7.4 % terms of high flow estimation relative to in situ gauge measurements. The precision obtained with the different methods was analyzed by running Monte Carlo simulations and also showed comparable values for the three approaches with standard deviations found between 8.2 and 25.8 % of the high flow estimates.

Description: Water management simulation games and the construction of knowledge Hydrology and Earth System Sciences Discussions, 9, 3063-3085, 2012 Author(s): M. Rusca, J. Heun, and K. Schwartz In recent years simulations have become an important part of teaching activities. The reasons behind the popularity of simulation games are twofold. On the one hand, emerging theories on how people learn have called for an experienced-based learning approach. On the other hand, the demand for water management professionals has changed. Three important developments are having considerable consequences for water management programmes, which educate and train these professionals. These developments are the increasing emphasis on integration in water management, the characteristics and speed of reforms in the public sector and the shifting state-society relations in many countries. In response to these developments, demand from the labour market is oriented toward water professionals who need to have both a specialist in-depth knowledge in their own field, as well as the ability to understand and interact with other disciplines and interests. In this context, skills in negotiating, consensus building and working in teams are considered essential for all professionals. In this paper we argue that simulation games have an important role to play in (actively) educating students and training the new generation of water professionals to respond to the above-mentioned challenges. At the same time, simulations are not a panacea for learners and teachers. Challenges of using simulations games include the demands it places on the teacher. Setting up the simulation game, facilitating the delivery and ensuring that learning objectives are achieved requires considerable knowledge and experience as well as considerable time-inputs of the teacher. Moreover, simulation games usually incorporate a case-based learning model, which may neglect or underemphasize theories and conceptualization. For simulations to be effective they have to be embedded in this larger theoretical and conceptual framework. Simulations, therefore, complement rather than substitute traditional teaching methods.

Description: Evaluation of a complementary based model for mapping land surface evapotranspiration Hydrology and Earth System Sciences Discussions, 9, 3029-3062, 2012 Author(s): Z. Sun, Q. Wang, Z. Ouyang, and Y. Yang A modified Priestley-Taylor (P-T) equation was proposed by Venturini et al. (2008) to map actual evapotranspiration (ET) based solely on satellite remote sensing data, involving a parameter based on a scaled temperature between dew point temperature and surface temperature. In this study, however, theoretical analyses and field experimental evidence show that it is hard to obtain this scaled temperature using dew point temperature and surface temperature. This study also presents a new parameterization method using air temperature, surface temperature, and surface temperature of a reference dry surface. The actual ET estimates obtained by means of our proposed parameterization method are validated at a site scale, and a case study is conducted to map actual ET from Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER) images using our proposed method. Results of ground-based validation and a case study of mapping ET using ASTER images indicate that the improvement on the modified P-T equation proposed by Venturini et al. (2008) can contribute to generating reliable actual ET.

Description: Prioritization of water management under climate change and urbanization using multi-criteria decision making methods Hydrology and Earth System Sciences, 16, 801-814, 2012 Author(s): J.-S. Yang, E.-S. Chung, S.-U. Kim, and T.-W. Kim This paper quantifies the transformed effectiveness of alternatives for watershed management caused by climate change and urbanization and prioritizes five options using multi-criteria decision making techniques. The climate change scenarios (A1B and A2) were obtained by using a statistical downscaling model (SDSM), and the urbanization scenario by surveying the existing urban planning. The flow and biochemical oxygen demand (BOD) concentration duration curves were derived, and the numbers of days required to satisfy the environmental flow requirement and the target BOD concentration were counted using the Hydrological Simulation Program-Fortran (HSPF) model. In addition, five feasible alternatives were prioritized by using multi-criteria decision making techniques, based on the driving force-pressure-state-impact-response (DPSIR) framework and cost component. Finally, a sensitivity analysis approach for MCDM methods was conducted to reduce the uncertainty of weights. The result indicates that the most sensitive decision criterion is cost, followed by criteria response, driving force, impact, state and pressure in that order. As it is certain that the importance of cost component is over 0.127, construction of a small wastewater treatment plant will be the most preferred alternative in this application.

Description: Influence of parallel computational uncertainty on simulations of the Coupled General Climate Model Geoscientific Model Development, 5, 313-319, 2012 Author(s): Z. Song, F. Qiao, X. Lei, and C. Wang This paper investigates the impact of the parallel computational uncertainty due to the round-off error on climate simulations using the Community Climate System Model Version 3 (CCSM3). A series of sensitivity experiments have been conducted and the analyses are focused on the Global and Nino3.4 average sea surface temperatures (SST). For the monthly time series, it is shown that the amplitude of the deviation induced by the parallel computational uncertainty is the same order as that of the climate system change. However, the ensemble mean method can reduce the influence and the ensemble member number of 15 is enough to ignore the uncertainty. For climatology, the influence can be ignored when the climatological mean is calculated by using more than 30-yr simulations. It is also found that the parallel computational uncertainty has no distinguishable effect on power spectrum analysis of climate variability such as ENSO. Finally, it is suggested that the influence of the parallel computational uncertainty on Coupled General Climate Models (CGCMs) can be a quality standard or a metric for developing CGCMs.

Description: Precipitation fields interpolated from gauge stations versus a merged radar-gauge precipitation product: influence on modelled soil moisture at local scale and at SMOS scale Hydrology and Earth System Sciences Discussions, 9, 3385-3413, 2012 Author(s): J. T. dall'Amico, W. Mauser, F. Schlenz, and H. Bach For the validation of coarse resolution soil moisture products from missions such as the Soil Moisture and Ocean Salinity (SMOS) mission, hydrological modelling of soil moisture is an important tool. The spatial distribution of precipitation is among the most crucial input data for such models. Thus, reliable time series of precipitation fields are required, but these often need to be interpolated from data delivered by scarcely distributed gauge station networks. In this study, a commercial precipitation product derived by Meteomedia AG from merging radar and gauge data is introduced as a novel means of adding the promising area-distributed information given by a radar network to the more accurate, but point-like measurements from a gauge station network. This precipitation product is first validated against an independent gauge station network. Further, the novel precipitation product is assimilated into the hydrological land surface model PROMET for the Upper Danube Catchment in southern Germany, one of the major SMOS calibration and validation sites in Europe. The modelled soil moisture fields are compared to those obtained when the operational interpolation from gauge station data is used to force the model. The results suggest that the assimilation of the novel precipitation product can lead to deviations of modelled soil moisture in the order of 0.15 m 3 m −3 on small spatial (∼1 km 2 ) and short temporal resolutions (∼1 day). As expected, after spatial aggregation to the coarser grid on which SMOS data are delivered (~195 km 2 ), these differences are reduced to the order of 0.04 m 3 m −3 , which is the accuracy benchmark for SMOS. The results of both model runs are compared to brightness temperatures measured by the airborne L-band radiometer EMIRAD during the SMOS Validation Campaign 2010. Both comparisons yield equally good correlations, confirming the model's ability to realistically model soil moisture fields in the test site. The fact that the two model runs perform similarly in the comparison is likely associated with the lack of substantial rain events before the days on which EMIRAD was flown.

Description: An integrated uncertainty and ensemble-based data assimilation approach for improved operational streamflow predictions Hydrology and Earth System Sciences, 16, 815-831, 2012 Author(s): M. He, T. S. Hogue, S. A. Margulis, and K. J. Franz The current study proposes an integrated uncertainty and ensemble-based data assimilation framework (ICEA) and evaluates its viability in providing operational streamflow predictions via assimilating snow water equivalent (SWE) data. This step-wise framework applies a parameter uncertainty analysis algorithm (ISURF) to identify the uncertainty structure of sensitive model parameters, which is subsequently formulated into an Ensemble Kalman Filter (EnKF) to generate updated snow states for streamflow prediction. The framework is coupled to the US National Weather Service (NWS) snow and rainfall-runoff models. Its applicability is demonstrated for an operational basin of a western River Forecast Center (RFC) of the NWS. Performance of the framework is evaluated against existing operational baseline (RFC predictions), the stand-alone ISURF and the stand-alone EnKF. Results indicate that the ensemble-mean prediction of ICEA considerably outperforms predictions from the other three scenarios investigated, particularly in the context of predicting high flows (top 5th percentile). The ICEA streamflow ensemble predictions capture the variability of the observed streamflow well, however the ensemble is not wide enough to consistently contain the range of streamflow observations in the study basin. Our findings indicate that the ICEA has the potential to supplement the current operational (deterministic) forecasting method in terms of providing improved single-valued (e.g., ensemble mean) streamflow predictions as well as meaningful ensemble predictions.

Description: Advancing data assimilation in operational hydrologic forecasting: progresses, challenges, and emerging opportunities Hydrology and Earth System Sciences Discussions, 9, 3415-3472, 2012 Author(s): Y. Liu, A. H. Weerts, M. Clark, H.-J. Hendricks Franssen, S. Kumar, H. Moradkhani, D.-J. Seo, D. Schwanenberg, P. Smith, A. I. J. M. van Dijk, N. van Velzen, M. He, H. Lee, S. J. Noh, O. Rakovec, and P. Restrepo Data assimilation (DA) holds considerable potential for improving hydrologic predictions as demonstrated in numerous research studies. However, advances in hydrologic DA research have not been adequately or timely implemented into operational forecast systems to improve the skill of forecasts to better inform real-world decision making. This is due in part to a lack of mechanisms to properly quantify the uncertainty in observations and forecast models in real-time forecasting situations and to conduct the merging of data and models in a way that is adequately efficient and transparent to operational forecasters. The need for effective DA of useful hydrologic data into the forecast process has become increasingly recognized in recent years. This motivated a hydrologic DA workshop in Delft, The Netherlands in November 2010, which focused on advancing DA in operational hydrologic forecasting and water resources management. As an outcome of the workshop, this paper reviews, in relevant detail, the current status of DA applications in both hydrologic research and operational practices, and discusses the existing or potential hurdles and challenges in transitioning hydrologic DA research into cost-effective operational forecasting tools, as well as the potential pathways and newly emerging opportunities for overcoming these challenges. Several related aspects are discussed, including (1) theoretical or mathematical considerations in DA algorithms, (2) the estimation of different types of uncertainty, (3) new observations and their objective use in hydrologic DA, (4) the use of DA for real-time control of water resources systems, and (5) the development of community-based, generic DA tools for hydrologic applications. It is recommended that cost-effective transition of hydrologic DA from research to operations should be helped by developing community-based, generic modelling and DA tools or frameworks, and through fostering collaborative efforts among hydrologic modellers, DA developers, and operational forecasters.

Description: Impact of climate change on sediment yield in the Mekong River Basin: a case study of the Nam Ou Basin, Lao PDR Hydrology and Earth System Sciences Discussions, 9, 3339-3384, 2012 Author(s): B. Shrestha, M. S. Babel, S. Maskey, A. van Griensven, S. Uhlenbrook, A. Green, and I. Akkharath This paper evaluates the impact of climate change on sediment yield in the Nam Ou Basin located in Northern Laos. The Soil and Water Assessment Tool (SWAT) is used to assess future changes in sediment flux attributable to climate change. Future precipitation and temperature series are constructed through a delta change approach. As per the results, in general, temperature as well as precipitation show increasing trends in both scenarios, A2 and B2. However, monthly precipitation shows both increasing and decreasing trends. The simulation results exhibit that the wet and dry seasonal and annual stream discharges are likely to increase (by up to 15, 17 and 14% under scenario A2; and 11, 5 and 10% under scenario B2 respectively) in the future, which will lead to increased wet and dry seasonal and annual sediment yields (by up to 39, 28 and 36% under scenario A2; and 23, 12 and 22% under scenario B2 respectively). A higher discharge and more sediment flux are expected during the wet seasons, although the changes, percentage-wise, are observed to be higher during the dry months. In conclusion, the sediment yield from the Nam Ou Basin is likely to increase with climate change, which strongly suggests the need for basin-wide sediment management strategies in order to reduce the negative impact of this change.

Description: Assessment of a physical-biogeochemical coupled model system for operational service in the Baltic Sea Ocean Science Discussions, 9, 835-876, 2012 Author(s): Z. Wan, J. She, M. Maar, L. Jonasson, and J. Baasch-Larsen Thanks to the abundant observation data, we are able to deploy the traditional point-to-point comparison and statistical measures in combination with a comprehensive model validation scheme to assess the skills of the biogeochemical model ERGOM in providing an operational service for the Baltic Sea. The model assessment concludes that the operational products can resolve the main observed seasonal features for phytoplankton biomass, dissolved inorganic nitrogen, dissolved inorganic phosphorus and dissolved oxygen in euphotic layers, as well as their vertical profiles. This assessment reflects that the model errors of the operational system at the current stage are mainly caused by insufficient light penetration, excessive organic particle export downward, insufficient regional adaptation and some of improper initialization. This study highlights the importance of applying multiple schemes in order to assess model skills rigidly and identify main causes for major model errors.

Description: Numerical tools to estimate the flux of a gas across the air-water interface and assess the heterogeny of its forcing functions Ocean Science Discussions, 9, 909-975, 2012 Author(s): V. M. N. de C. da S. Vieira A numerical tool was developed for the estimation of gas fluxes across the air water interface. The primary objective is to use it to estimate CO 2 fluxes. Nevertheless application to other gases is easily accomplished by changing the values of the parameters related to the physical properties of the gases. A user friendly software was developed allowing to build upon a standard kernel a custom made gas flux model with the preferred parametrizations. These include single or double layer models; several numerical schemes for the effects of wind in the air-side and water-side transfer velocities; the effect of turbulence from current drag with the bottom; and the effects on solubility of water temperature, salinity, air temperature and pressure. It was also developed an analysis which decomposes the difference between the fluxes in a reference situation and in alternative situations into its several forcing functions. This analysis relies on the Taylor expansion of the gas flux model, requiring the numerical estimation of partial derivatives by a multivariate version of the collocation polynomial. Both the flux model and the difference decomposition analysis were tested with data taken from surveys done in the lagoonary system of Ria Formosa, south Portugal, in which the CO 2 fluxes were estimated using the IRGA and floating chamber method whereas the CO 2 concentrations were estimated using the IRGA and degasification chamber. Observations and estimations show a remarkable fit.

Description: Precipitation as the main driver of Neoglacial fluctuations of Gualas glacier, Northern Patagonian Icefield Climate of the Past, 8, 519-534, 2012 Author(s): S. Bertrand, K. A. Hughen, F. Lamy, J.-B. W. Stuut, F. Torrejón, and C. B. Lange Glaciers are frequently used as indicators of climate change. However, the link between past glacier fluctuations and climate variability is still highly debated. Here, we investigate the mid- to late-Holocene fluctuations of Gualas Glacier, one of the northernmost outlet glaciers of the Northern Patagonian Icefield, using a multi-proxy sedimentological and geochemical analysis of a 15 m long fjord sediment core from Golfo Elefantes, Chile, and historical documents from early Spanish explorers. Our results show that the core can be sub-divided into three main lithological units that were deposited under very different hydrodynamic conditions. Between 5400 and 4180 cal yr BP and after 750 cal yr BP, sedimentation in Golfo Elefantes was characterized by the rapid deposition of fine silt, most likely transported by fluvio-glacial processes. By contrast, the sediment deposited between 4130 and 850 cal yr BP is composed of poorly sorted sand that is free of shells. This interval is particularly marked by high magnetic susceptibility values and Zr concentrations, and likely reflects a major advance of Gualas glacier towards Golfo Elefantes during the Neoglaciation. Several thin silt layers observed in the upper part of the core are interpreted as secondary fluctuations of Gualas glacier during the Little Ice Age, in agreement with historical and dendrochronological data. Our interpretation of the Golfo Elefantes glaciomarine sediment record in terms of fluctuations of Gualas glacier is in excellent agreement with the glacier chronology proposed for the Southern Patagonian Icefield, which is based on terrestrial (moraine) deposits. By comparing our results with independent proxy records of precipitation and sea surface temperature, we suggest that the fluctuations of Gualas glacier during the last 5400 yr were mainly driven by changes in precipitation in the North Patagonian Andes.

Description: A critical humidity threshold for monsoon transitions Climate of the Past, 8, 535-544, 2012 Author(s): J. Schewe, A. Levermann, and H. Cheng Monsoon systems around the world are governed by the so-called moisture-advection feedback. Here we show that, in a minimal conceptual model, this feedback implies a critical threshold with respect to the atmospheric specific humidity q o over the ocean adjacent to the monsoon region. If q o falls short of this critical value q o c , monsoon rainfall over land cannot be sustained. Such a case could occur if evaporation from the ocean was reduced, e.g. due to low sea surface temperatures. Within the restrictions of the conceptual model, we estimate q o c from present-day reanalysis data for four major monsoon systems, and demonstrate how this concept can help understand abrupt variations in monsoon strength on orbital timescales as found in proxy records.