摘要：Three sources of uncertainty in model projections of precipitation change in China for the 21st century were separated and quantified: internal variability,inter-model variability,and scenario *** from models involved in the third phase and the fifth phase of the Coupled Model Intercomparison Project(CMIP3 and CMIP5) were compared to identify improvements in the robustness of projections from the latest generation of *** significant differences were found between CMIP3 and CMIP5 in terms of future precipitation projections over China,with the two datasets both showing future *** uncertainty can be attributed firstly to internal variability,and then to both inter-model and internal *** analysis revealed that the uncertainty in CMIP5 models has increased by about 10%–60% with respect to CMIP3,despite significant improvements in the latest generation of *** increase is mainly due to the increase of internal variability in the initial decades,and then mainly due to the increase of inter-model variability thereafter,especially by the end of this *** change in scenario uncertainty shows no major role,but makes a negative contribution to begin with,and then an increase later.

摘要：Changes in precipitation minus evaporation （P-E） are analyzed to investigate the possible impacts of climate change on water resource conditions in China. Simulations of SRES A1B and 20C3M scenarios from the WCRP CMIP3 GCMs are employed in the study. Time slice analysis shows that there would be more annual mean P-E across China in 2040-2055 and 2080-2099, compared to 1980-1999, with the largest percentage change over Northwest China and the Bohai Rim area. Precipitation and evaporation would also increase over entire China during these two periods. Annual mean P-E, precipitation, and evaporation averaged over the whole China and its eight sub-areas all yield generally upward trends during the 21st century. This indicates that on annual mean scale, the global warming related precipitation dominates the hydroclimate conditions in China. On seasonal mean scale, although precipitation is projected to increase over China, P-E exhibits both decreasing and increasing trends over certain regions of China. This suggests that the variation of global warming related evaporation dominates hydroclimate conditions over some parts of China, especially in northern China. Therefore, in hydroclimate condition projections, considering both evaporation and precipitation changes should be more reasonable than considering only precipitation.

摘要：The outputs of 17 models in the Coupled Model Intercomparison Project Phase 5 (CMIP5) are employed to investigate the temporal and spatial features of 2.0°C warming of the surface temperature over the globe and China under the Representative Concentration Pathways (RCP) 4.5 scenario. The simulations of the period 1860-1899 in the "historical" experiment are chosen as the baseline. The simulations for the 21st century in the RCP4.5 experiment are chosen as the future project. The multi-model ensemble mean (MME) shows that the global mean temperature would cross the 2.0°C warming threshold in 2047. Warming in most of the models would cross the threshold during 2030-2060. For local warming, high-latitude areas in the Northern Hemisphere show the fastest warming over the globe. Land areas warm substantially faster than the oceans. Most of the southern oceans would not exceed the 2.0°C warming threshold within the 21st century. Over China, surface warming is substantially faster than the global mean. The area-averaged warming would cross the 2.0°C threshold in 2034. Locally, Northwest China shows the fastest warming trend, followed by Central North China and Northeast China. Central China, East China, and South China are the last to cross the 2.0°C warming threshold. The diversity of the models is also estimated in this study. Generally, the spread among the models increases with time, and there is smaller spread among the models for the areas with the faster warming.

摘要：The Lancang–Mekong River basin(LMRB) is under increasing threat from global warming. In this paper, the projection of future climate in the LMRB is explored by focusing on the temperature change and extreme temperature events. First, the authors evaluate the bias of temperature simulated by the Weather research and Forecasting model. Then, correction is made for the simulation by comparing with observation based on the non-parametric quantile mapping using robust empirical quantiles(RQUANT) method. Furthermore, using the corrected model results, the future climate projections of temperature and extreme temperature events in this basin during 2016–35, 2046–65, and 2080–99 are analyzed. The study shows that RQUANT can effectively reduce the bias of simulation results. After correction, the simulation can capture the spatial features and trends of mean temperature over the LMRB, as well as the extreme temperature events. Besides, it can reproduce the spatial and temporal distributions of the major modes. In the future, the temperature will keep increasing, and the warming in the southern basin will be more intense in the wet season than the dry season. The number of extreme high-temperature days exhibits an increasing trend, while the number of extreme low-temperature days shows a decreasing trend. Based on empirical orthogonal function analysis, the dominant feature of temperature over this basin shows a consistent change. The second mode shows a seesaw pattern.

摘要：Coordinated numerical ensemble experiments with six different state-of-the-art atmosphere models were used to evaluate and quantify the impact of global SST(from reanalysis data)on the early winter Arctic warming during *** sets of experiments were designed:in the first set(EXP1),OISSTv2 daily sea-ice concentration and SST variations were used as the lower boundary forcing,while in the second set(EXP2)the SST data were replaced by the daily SST *** the results,the multi-model ensemble mean of EXP1 showed a nearsurface(~850 hPa)warming trend of 0.4℃/10 yr,which was 80%of the warming trend in the *** simulated warming trend was robust across the six models,with a magnitude of 0.36-0.50℃/10 *** global SST could explain most of the simulated warming trend in EXP1 in the mid and low troposphere over the Arctic,and accounted for 58%of the simulated near-surface *** results also suggest that the uppertropospheric warming(~200 hPa)over the Arctic in the reanalysis is likely not a forced signal;rather,it is caused by natural climate *** source regions that can potentially impact the early winter Arctic warming are explored and the limitations of the study are discussed.