摘要
将中尺度非静力模式MM5中的积云参数化Grell方案作了改进,使它含液态水含量,并用该模式对1998年6月29日08:00~30日08:00(北京时,下同)和7月1日08:00~2日08:00发生在淮河流域的两次特大暴雨进行数值模拟研究,同时通过采用不同高度上的Z-qr关系式将TRMM/PR(TropicalRainfallMeasuringMission/PrecipitationRadar)雷达得到的反射率资料计算出比含水量qr,然后用q′v=qv+qr取代原模式中的比湿qv。结果表明,将TRMM/PR雷达资料加入模式后,由于PR雷达具有较高的空间分辨率,能够很好地反映中小尺度系统的空间结构,使湿度值接近实际,缩短了中尺度系统的发展时间,使得模拟出来的降雨强度、雨量中心位置以及雨带形状更接近实况。
Numerical simulations of two heavy rain cases in the Changjiang-Huaihe river basin have been carried out with TRMM/PR (Tropical Rainfall Measuring Mission/Precipitation Radar) data incorporating into the PSU/NCAR meso-scale model MM5. First, rainwater mixing ratio %q-r% is obtained from different %Z-q-r% relations variating with height. Then, while specific humidity %q′-v% in the model is replace with %q-v%, where %q′-v=q-v+q-r%. Based on the above idea, TRMM/PR data is used to modify humidity obtained by conventional radiosound data. Simulation are performed and compared with the control run. The results show that both the heavy rainfall distribution and its heavy rain core amounts in sensitivity run are better than in control one.
出处
《高原气象》
CSCD
北大核心
2004年第5期635-642,共8页
Plateau Meteorology
基金
国家自然科学基金项目(49794030)资助