全球植被分布对气候影响的数值试验  

Numerical Experiment of the Influence of Global Vegetation Distribution on Climate

作　　者：曾红玲[1,2] 季劲钧[3] 吴国雄[2] 

机构地区：[1]中国气象局国家气候中心,北京100081 [2]中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室,北京100029 [3]中国科学院大气物理研究所东亚区域气候环境重点实验室,北京100029

出　　处：《大气科学》2010年第1期1-11,共11页Chinese Journal of Atmospheric Sciences

基　　金：国家重点基础研究发展规划项目2006CB403607;中国科学院重要方向项目KZCX2-YW-Q11-01;国家自然科学基金资助项目40875034;40821092;40730106

摘　　要：利用一个新的陆气双向耦合模式R42_AVIM,通过有无植被覆盖的对比试验分析,探讨了全球植被分布对气候和大气环流产生的潜在影响。得出:陆面植被覆盖使得地表特征参数发生行星尺度的明显改变,在叶面积指数大的热带和中高纬度森林带尤其显著。在现实植被分布下,陆地表面反照率减小,地表净辐射收支和地表潜热通量增加,而地表感热通量减小。植被叶面积指数比较大的区域地表温度降低,并且这种温度的改变一直延伸到对流层中上层,在热带表现为斜压结构,而在中高纬表现为相当正压结构。植被的存在使热带和中高纬度森林带的蒸发和相应的高层凝结潜热加热增强,从而增强了经圈环流的上升支,使得冬季在热带和南半球中纬度降水增多,夏季在热带和北半球中高纬地区降水明显增多;而经圈环流下沉支的增强致使副热带降水减少且更干旱。同时,植被的存在使大陆潜热释放增强,气温下降,减小了海陆温度对比,亚洲夏季风也有所减弱。The authors adopt a new two-way land-atmosphere coupled model R42_AVIM. By contrast of experiments with and without vegetation cover, the possible impact of global vegetation distribution on climate and atmosphere circulation is discussed. The results show that the actual vegetation coverage on land can alter the surface character- istic parameters obviously on planetary scale, especially for tropical rairdorest and boreal forest. Under the distribution of actual vegetation, the surface net radiation and the latent heat flux will increase, while the surface sensible heat flux will decrease. In the areas where the leaf area index （LAI） is relatively large, the surface temperature will decrease. Moreover, this effect can also extend to the middle and upper troposphere. In addition, the present vegetation distribution enhances the evaporation as well as the corresponding condensation latent heating in the tropics and mid-high latitudes, which makes the meridional circulation stronger. And then, the precipitation increases in the tropics and mid-high latitudes, while decreases in the subtropics. Meanwhile, vegetation can also reduce the sea- land temperature contrast and weaken the Asian summer monsoon.

关 键 词：陆气双向耦合模式R42_AVIM 植被分布 气候 大气环流 

分 类 号：P461[天文地球—大气科学及气象学]