CMA-GFS全球预报系统中的台风初始化

在CMA-GFS(CMA Global Forecast System)全球四维变分资料同化系统(4DVar)基础上,参照BDA(Bogus Data Assimilation)方法,建立了一个全球模式台风初始化方案.该方案通过4DVar同化窗口吸收诊断处理后的1 h间隔台风中心定位及中心气压信息,利用模式动力物理约束...

Typhoon initialization in the CMA global forecast system

A global model typhoon initialization scheme is developed based on the global four-dimensional variational data assimilation (4DVar) of CMA global forecast system (CMA-GFS) with reference to the BDA (Bogus Data Assimilation) method. The scheme assimilates 1 h interval information of typhoon center location and central sea level pressure diagnosed by interpolation method, and generates typhoon circulation using the model dynamic physical constraints within the 4DVar assimilation window. At the same time, errors in the central sea surface pressure are dynamically corrected using a technique that takes into account the model's ability to describe typhoon circulation. Experiments of 22 typhoon cases that occurred in the Northwest Pacific in 2016 show that the new scheme not only promotes the generation of typhoon circulation in the initial field, but also significantly reduces errors in the mean typhoon track and intensity predicted by the CMA global forecast system. Therefore, this scheme has a potential for operational application.