探空和飞机观测资料联合同化对台风“苏迪罗”(2015)数值模拟的影响研究

THE IMPACT OF JOINT ASSIMILATION OF RADIOSONDE AND AIRCRAFT OBSERVATIONS ON NUMERICAL SIMULATION OF TYPHOON “SOUDELOR”(2015)

基于中尺度数值天气预报模式WRF和WRFDA三维变分同化系统,针对2015年台风"苏迪罗"二次登陆过程,利用NCEP ADP提供的无线电探空、飞机报观测资料,同时同化两种资料,并进行36 h模拟预报,从台风移动路径、强度、降水及模式初始场改进等方面分析了同化模拟效果。结果表明,同时同化两种资料能够有效改善台风移动路径、中心附近最低气压的模拟。对浙闽降水关键区24 h降水的TS评分结果表明,该同化方案对台风降水的预报评分有一定程度的改进,尤其是中雨和特大暴雨的改进最明显。对于模式初始场的温度、相对湿度、纬向风、经向风在各高度上的均方根误差,除湿度外均有不同程度的减小。并且同化对于台风结构的模拟也有所调整。

Based on the mesoscale numerical weather prediction model WRF and WRF-3 DVAR assimilation system,assimilating the aircraft,radiosonde observations provided by NCEP ADP data at the same time and simulating the typhoon'Soudelor'for 36 hours,the assimilation effects are analysed from the aspects of the typhoon path,strength,precipitation and initial field.The results show that the assimilation of two kinds of data can effectively improve the simulation of the minimum pressure near the moving path and center.After assimilation,the root mean square error of the moving path is reduced by 14.846 km(about 17.5%),and the root mean square error of the lowest pressure is reduced by 1.1 hPa,which is improved by about 18.1%.TS scores of 24 hours precipitation in key areas Zhejiang and Fujian provinces shows that the assimilation scheme has a certain degree of improvement in the prediction of typhoon precipitation,especially the improvement of moderate rain and torrential rain.The root mean square error of temperature,relative humidity,zonal wind and meridional wind at different heights of the model initial field is reduced to varying degrees except humidity.The temperature is reduced by 0.13 degrees averagely at all heights,about19%,the relative humidity increased by 0.5%,about 0.6%,the zonal wind decreased by 0.27 m/s,about9.9%,and the meridional wind decreased by 0.38 m/s,about 13.4%.According to the vertical distribution of the mean square root error,the improvement of temperature,relative humidity,zonal wind and meridional wind at the height of 950 hPa and 850 hPa are more obvious.And it also modify the simulated structure of typhoon.