下垫面改变导致局地气候变化的理论分析

摘要

运用气柱内辐射,相变,对流间的平衡及地表能量平衡条件研究了由于地表状况改变,即植被退化所造成的局地气候变化,结果表明地表反射率的加大及地面热通量的变化造成中国北方降水量的减少和温度的增加.粗糙度的减少也能造成降水量减少和温度增加,这些结果与数值模拟一致.考虑平流作用以后,上述特征不变,但降水及温度改变量发生变化.在全球增暖背景下,降水减少和温度增加要更剧烈些.%The local climate change induced by the change of landuse, i.e., the degeneration of vegetation is studied by the consideration of the equilibrium among radiation, phase change and convection in an air column and the energy balance condition on the ground surface. The result shows that the increase of ground albedo and the change of the surface heat flux as well as the decrease of the surface roughness length may induce the decrease of precipitation and the increase of temperature in the northern China, similar to the numerical simulation. Considering advection, this conclusion is also true except the amounts of the decrease of precipi tation and the increase of temperature are changed. The decrease of precipitation and the increase of temperalure will be more serious in case of global warming.