沙漠化扩展对区域气候影响的数值模拟研究

Numerical Simulation of Influence of Expanded Desertification Area on Climate in China

利用GCM -SSiB全球大气环流谱模式 ,设计两组数值模拟试验 (即控制试验 (CE)和沙漠面积扩大试验(DE) ) ,研究了大陆沙漠化对我国区域气候变化的影响。模拟结果表明 :沙区扩展后 ,大陆年平均地表温度降低 ,海平面气压上升 ,纬向风速、季风加强 ,夏季低空上升运动减弱 ,冬季下沉运动增强 ,降雨量显著减少 ,地表蒸发、感热和潜热通量亦显著减少。我国区域气候随大陆沙漠化扩展趋向冷干、风速加大 ,沙漠扩展与区域气候恶化存在正反馈。

The GCM-SSiB global spectral model has been used to study the influence of desertification expanding over China on regional climate. Two numerical experiments are set up. The results show that widen desertification made annual mean surface air temperature lower, sea level pressure higher, low level zonal wind velocity and the monsoon stronger, summer updraft motion weaker, winter downdraft motion stronger, precipitation decreased obviously, also surface evaporation flux, sensible heat flux and latent heat flux decreased obviously. Regional climate will incline to be cold and dry and wind velocity will strengthen along with desertification. There exists positive feedback between desertification and regional climate deterioration.