雷达和卫星资料在中尺度模式中的初步应用

THE IMPACT OF USING RADAR AND SATELLITE DATA ON MESO-SCALE MODEL NUMERICAL SIMULATION

本文利用非静力中尺度模式 MM5对 1998年 7月 2 0日～ 2 1日发生在湖北东部地区的特大暴雨过程作数值模拟 ,同时将不同时间的雷达和卫星资料适时加入模式改变当时模式中的水汽场 ,并与控制试验进行比较分析 ,结果表明 :加入雷达和卫星资料后的数值模拟 ,由于修正了暴雨区及其邻近区域对流层中低层水汽场 ,雨区位置和雨量中心值比仅用探空资料的控制试验更接近实况。雷达与卫星资料引入模式对于 2 4小时降雨产生的效果不同 ,雷达资料的影响是局部的 ,范围较小 ,卫星资料影响范围较大 ,而且适时加入雷达、卫星资料能够及时通过水汽场修正 ,使 2 4小时预报的雨区范围和中心强度与实况更加接近 。

Numerical simulations of one heavy rainfall cases in Wuhan province have been carried out with radar and satellite data incorporating into the PSU/NCAR mesoscale model 5 (MM5).The radar and satellite data are used to change humidity analysis obtained by conventional radiosound data and then simulations are performed and compared with the control cases.Results show that both of the heavy rainfall distribution and its maximum amounts in sensitivity cases are further improved than those without using radar or satellite data.It implies that the enhancement of humidity by radar and satellite data is essential for improving the results of heavy rainfall numerical simulations.And we compared the results of using radar data with the results of using satallite data.Results show that the extent of the impact of using radar data on the numerical simulation is smaller,and that the extent of the impact of using satellite data on the numerical simulation is larger.The results of assimilating radar and satellite data in numerical model at the same time is relate to the characteristic of the rainfall weather system.