地表动量通量对一次华南前汛期降水影响的数值模拟  

Numerical Smulation of the Effect of Surface Momentum Flux on a Frontal Precipitation during Pre-Rainy Season of South China

作　　者：臧增亮[1] 何亿强[2] 赵思雄[1] 

机构地区：[1]中国科学院大气物理研究所大气科学和地球流体力学国家重点实验室 [2]北京航天飞行控制中心气象中心

出　　处：《高原气象》2008年第4期778-786,共9页Plateau Meteorology

基　　金：中国科学院大气物理研究所大气科学和地球流体力学国家重点实验室开放课题;国家自然科学基金项目(40705020)共同资助

摘　　要：利用ARPS模式,对一次华南前汛期锋面降水进行了数值模拟和敏感性试验,探讨了动量通量对降水的影响机制。结果表明,去掉地表动量通量对降水率可产生正、反两方面的影响,并大致可分为两个阶段,在积分的前一阶段,动量通量为零区域上空的急流核风速增大,其左前方的辐合区和涡度的强度也相应增大,从而导致降水率增大;而在后一阶段,动量通量为零的区域上空埃克曼抽吸减弱,边界层内的辐合强度和垂直上升运动也相应减弱,从而导致降水率减小。One control test and three sensitivity experiments in the pre-rainy season in South China. were carried out using ARPS （the Advanced Regional Prediction System） model, the effect of the surface momentum flux on precipitation was discussed. The most complex scheme of surface physics options was adopted in the control experiment. On the base of control experiment, the surface momentum flux on land and water were removed in the sensitivity experiments, respectively. The results show that, both on land and water, the rate of rainfall in the earlier phase will increase when the surface momentum flux is removed. But in the following phase, the rate of rainfall tends to decrease on the region with removed surface momentum flux. It is pointed out by the analysis that, on the earlier phase, the removed surface momentum flux can increase the surface wind velocity, and strengthen the low jet stream through turbulent motion and convection motion, which will result in increased rate of rainfall. However, in the following phase, the Ekman pumping tends to weaken in the region with removed surface momentum flux, which will result in a decrease in precipitation rate.

关 键 词：地表动量通量 华南前汛期 数值模拟 敏感性试验 

分 类 号：P426.615[天文地球—大气科学及气象学] TP69[自动化与计算机技术—控制理论与控制工程]