北半球陆面过程对全球变暖响应特征的初步分析

Preliminary Analysis on Response Features of Land Surface Processes over the Northern Hemisphere to Global Warming

利用NCAR气候系统模式CCSM3.0 IPCC AR420世纪气候(20C3M)和21世纪SRES A1B排放情景下的模拟结果,着重分析了未来北半球陆面情况对全球变暖的总体响应特征。对比分析模式对20世纪和21世纪SRES A1B情景下的模拟结果表明:北半球陆面的水、热过程在全球变暖背景下将发生显著的变化。伴随全球地面温度的持续升高,北半球陆面的净辐射通量、感热通量和潜热通量均表现出不同程度的上升趋势,其中潜热通量的增幅明显高于感热通量;伴随着全球变暖,地表的水循环也发生了明显的变化,具体表现为北半球降水持续增多,陆面蒸发明显增加,地表径流也呈现出总体增加的趋势,但土壤含水量则表现出减少的趋势。

Analyzed here are the model results of two group experiments from NCAR CCSM3.0 IPCC AR4 simulations：CCSM3.0 climate of the 20 th century run（20C3M） and CCSM3.0 SRES A1B 21st century run.By comparing with 20C 3M results,the differences given by SRES A1B scenario 21st century run are investigated to disclose the possible changes in thermal and hydrological features of land surface processes over the Northern Hemisphere induced by global warming.The results show that the ground temperature increase significantly under global warming.Increasing trends are also found in the surface net radiation flux,sensible heat flux and latent heat flux.The increase in latent heat flux is more significant than that in the sensible heat flux.The hydrological cycle also exhibts significant response to global warming.Associated with global warming,land precipitation,evaporation and runoff increase evidently,but the soil water content decreases on the whole.