一次台风登陆过程的变分同化模拟试验

Variational assimilation experiment on landfall of typhoon

本文主要对0509号台风"麦莎"的登陆过程进行模拟试验,把云迹风资料引入三维变分同化系统,分析了同化水汽通道和红外通道的云迹风资料对初始场的影响;利用美国新一代中尺度模式WRF针对台风登陆前后过程做了48 h数值模拟试验,模拟结果表明:引入同化云迹风资料后,对模拟台风登陆前后的路径移向,降雨分布及强度变化方面,都有一定程度的改善,进而初步探讨了"麦莎"台风陆上长期维持的机制。

A numerical experiment is conducted on the landfall of typhoon Matsa（0509） mainly in this paper. Firstly, cloud drift winds have been added to the three-dimensional variational data assimilation system in order to find impact of water vapor winds and infrared cloud drift winds on initial field; then, with the initial field found out by the assimilation , the landfall process of typhoon Matsa has been studied by a 48 h numerical experiment through the WRF model. It is found that the evolution of the track, precipitation distributions and intensity change can be provided reasonably from the model result, furthermore, the sustaining mechanism of typhoom Matsa is also studied .