ALBERT

Beschreibung: Potential changes in glacier area, mass balance and runoff in the Yarkant River Basin (YRB) and Beida River Basin (BRB) are projected for the period from 2011 to 2050 employing the modified monthly degree-day model forced by climate change projection. Future monthly air temperature and precipitation were derived from the simple average of 17, 16 and 17 GCM projections following the A1B, A2 and B1 scenarios, respectively. These data were downscaled to each station employing the Delta method, which computes differences between current and future GCM simulations and adds these changes to observed time-series. Model parameters calibrated with observations or results published in the literature between 1961 and 2006 were kept unchanged. Annual glacier runoff in YRB is projected to increase until 2050, and the total runoff over glacier area in 1970 is projected to increase by about 13–35% during 2011–2050 relative to the average during 1961–2006. Annual glacier runoff and the total runoff over glacier area in 1970 in BRB is projected to increase initially and then to reach a tipping point during 2011–2030. There are prominent increases in summer, but only small increase in May and October of glacier runoff in YRB, and significantly increases during late spring and early summer and significant decreases in July and late summer of glacier runoff in BRB. This study highlights the great differences among basins in their response to future climate warming. The specific runoff from areas exposed after glacier retreat relative to 1970 is projected to general increasing, which must be considered when evaluating the potential change of glacier runoff. Copyright © 2011 John Wiley & Sons, Ltd.

Beschreibung: Global hydrological modeling is affected by three sources of uncertainty: (i) the choice of the global climate model (GCM) used to provide meteorological forcing data; (ii) the choice of future greenhouse gas concentration scenario; and (iii) the choice of the decade used to derive the bias correction parameters. We present a comparative analysis of these uncertainties and compare them to the inter-annual variability. The analysis focuses on discharge, integrated runoff and total precipitation over ten large catchments, representative of different climatic areas of the globe. Results are similar for all catchments, all hydrological variables and throughout the year with few exceptions. We find that the choice of different decadal periods over which to derive the bias correction parameters is a source of comparatively minor uncertainty, while other sources play larger and similarly significant roles. This is true for both the means and the extremes of the studied hydrological variables.

Beschreibung: A plume of ultrafine particles was observed downwind of the Karlsruhe city and industrial area during the COPS/TRACKS Lagrangian airborne experiment in summer 2007. These ultrafine particles were identified as nucleation-generated aerosols from emissions of a coal-fired power plant and an adjacent refinery, the two main emitters of sulphur dioxide in the area. Modelling the production and growth of aerosols with the COSMO-ART model required, in agreement with the known emission sources, a strong elevated source of sulphur dioxide to explain the temporal evolution of the particle plume. The power plant at Karlsruhe Rheinhafen emits from a 233 m high chimney. The ultrafine particles produced from these fossil-fuel-related sources were the dominant fraction of all ultrafine particles in the rural area of the Kraichgau downwind of Karlsruhe, exceeding all other anthropogenic sources and are suspected of being the major contribution to the number of cloud condensation nuclei (CCN) on a regional scale. Compared to previous investigations on the sulphur chemistry in power-plant plumes, emissions from this power plant, which is equipped with modern stack-gas cleaning technology, had a higher yield of nucleation-mode aerosols as CCN precursors per emitted sulphur dioxide mass. Copyright © 2011 Royal Meteorological Society

Beschreibung: Considering the complex spatial and vertical structure of the South Asian summer monsoon (SASM), the validation of a regional climate model (RCM) dealing with only a few surface variables is considered insufficient. Therefore, we have proposed an evaluation framework for the better assessment of the capability of an RCM in capturing the fundamental structure of SASM. This framework has been applied to the regional climate model REMO using ERA40 lateral boundary conditions for the period 1961–2000. The application of framework yielded satisfactory performance of REMO in capturing the lower, middle, and upper component of the SASM circulation. REMO has higher correlation between different SASM indices as compared to ERA40, showing its ability in capturing the dynamical link between these indices better than ERA40. We have employed different criteria for the assessment of the monsoon onset, and the movement of the Intertropical Convergence Zone (ITCZ) during the boreal summer and REMO has captured these phenomena reasonably well. The model has also shown the association of the meridional temperature gradient with the easterly shear of zonal winds. These results lead us to the conclusion that REMO is well suited for long-term climate change simulations to examine projected future changes in the complex SASM system. Copyright © 2011 Royal Meteorological Society

Beschreibung: The present study examines the precipitation variability over the South Asian monsoon heat low region and associated teleconnections using high resolution (T106L31) climate simulations performed with the ECHAM5 model. It is found that an intensification of the heat low in response to enhanced precipitation/convection over northwestern India-Pakistan (NWIP) can induce large-scale circulation anomalies that resemble the northern summer circumglobal teleconnection (CGT) wave-like pattern extending well into the Asian monsoon region. Accordingly the wave-like response to rainfall increase over the heat low region is associated with anomalous ascent over northern China and descent over the South China Sea. Additionally, small but statistically significant lead-lag correlations between the heat low and precipitation over northern China further suggest that the detected signal pertains to the true features of the process. On the other hand, suppressed convection and rainfall over the heat low region do not reveal any significant large-scale circulation anomalies.

Beschreibung: The retreat of mountain glaciers and ice caps has dominated the rise in global sea level and are likely to remain an import component of eustatic sea-level rise in the 21st century. Mountain glaciers are critical in supplying freshwater to populations inhabiting the valleys downstream who heavily rely on glacier runoff, such as arid and semi-arid regions of western China. Owing to recent climate warming and the consequent rapid retreat of many glaciers, it is essential to evaluate the long-term change in glacier melt water production, especially when considering the glacier area change. This paper describes the structure, principles and parameters of a modified monthly degree-day model considering glacier area variation. Water balances in different elevation bands are calculated with full consideration of the monthly precipitation gradient and air temperature lapse rate. The degree-day factors for ice and snow are tuned by comparing simulated variables to observation data for the same period, such as mass balance, equilibrium line altitude and glacier runoff depth. The glacier area-volume scaling factor is calibrated with the observed glacier area change monitored by remote sensing data of seven sub-basins of the Tarim interior basin. Based on meteorological data, the glacier area, mass balance and runoff are estimated. The model can be used to evaluate the long term changes of melt water in all glacierized basins of western China, especially for those with limited observation data. Copyright © 2011 John Wiley & Sons, Ltd.

Beschreibung: The glacier mass balance, area change, and glacier runoff in the Yarkant River Basin (YRB) and the Beida River Basin (BRB) are estimated for the period from 1961 to 2006 by employing a modified monthly degree-day model. Comparisons between the simulated and observed mass balance, equilibrium line altitude, and glacier runoff suggest that the model can be used to analyze the long-term changes of glacier mass balance and runoff in the YRB and the BRB. The glacier mass balances of the YRB and the BYB both have a significantly decreasing trend with −4.39 mm a -1 and −8.15 mm a -1 from 1961 to 2006 owing to significantly increased ablation caused by increasing summer air temperatures, especially since 1996. The total runoff in glacier areas has a significant increasing trend with 0.23 × 10 8  m 3 a -1 and 0.02 × 10 8  m 3 a -1 in the YRB and the BRB, respectively. By comparing the mean mass balance during 1961 to 1986 and that during 1987 to 2006, the sensitivity of the glacier mass balance to temperature of the BRB is 0.33 m a -1  °C, nearly twice as much as that of the YRB 0.16 m a -1  °C. The primary cause of this difference of glacier temperature sensitivity in the YRB and the BRB is that the glacier elevation band area weighted altitude of the YRB is about 700 m higher than that of BRB. The glacier elevation band area weighted summer air temperature in the YRB is around 2 °C lower than that of the BRB. Therefore, the annual positive degree day of the YRB and the BRB increase by about 21.0 °C and 77.3 °C respectively when the summer air temperature increases by 1 °C , resulting into more glacier ablation and runoff in the BRB than in the YRB. Copyright © 2011 John Wiley & Sons, Ltd.

Beschreibung: While increasing the terrestrial biomass is the most promising method to withdraw CO2 from the atmosphere, the long‐term storage of biogenic carbon plays a preponderant role for climate change mitigation. Biomass pyrolysis could convert sustainably produced biomass into solid (biochar), liquid (bio‐oil), and gaseous carbonaceous products, which allow long‐term storage in soils, biomaterials, and geological deposits. We review this new concept, now termed pyrolytic carbon capture and storage (PyCCS), which is expected to evolve into a decisive tool for future agriculture (biochar) and bio‐economy (biochar, bio‐oil, biofuels) serving climate change mitigation and the sustainable development goals simultaneously. Abstract The growth of biomass is considered the most efficient method currently available to extract carbon dioxide from the atmosphere. However, biomass carbon is easily degraded by microorganisms releasing it in the form of greenhouse gases back to the atmosphere. If biomass is pyrolyzed, the organic carbon is converted into solid (biochar), liquid (bio‐oil), and gaseous (permanent pyrogas) carbonaceous products. During the last decade, biochar has been discussed as a promising option to improve soil fertility and sequester carbon, although the carbon efficiency of the thermal conversion of biomass into biochar is in the range of 30%–50% only. So far, the liquid and gaseous pyrolysis products were mainly considered for combustion, though they can equally be processed into recalcitrant forms suitable for carbon sequestration. In this review, we show that pyrolytic carbon capture and storage (PyCCS) can aspire for carbon sequestration efficiencies of 〉70%, which is shown to be an important threshold to allow PyCCS to become a relevant negative emission technology. Prolonged residence times of pyrogenic carbon can be generated (a) within the terrestrial biosphere including the agricultural use of biochar; (b) within advanced bio‐based materials as long as they are not oxidized (biochar, bio‐oil); and (c) within suitable geological deposits (bio‐oil and CO2 from permanent pyrogas oxidation). While pathway (c) would need major carbon taxes or similar governmental incentives to become a realistic option, pathways (a) and (b) create added economic value and could at least partly be implemented without other financial incentives. Pyrolysis technology is already well established, biochar sequestration and bio‐oil sequestration in soils, respectively biomaterials, do not present ecological hazards, and global scale‐up appears feasible within a time frame of 10–30 years. Thus, PyCCS could evolve into a decisive tool for global carbon governance, serving climate change mitigation and the sustainable development goals simultaneously.