一次黄海爆发性气旋的观测分析和数值模拟研究

Observational analyses and WRF numerical modeling of an explosive cyclone over the Huanghai Sea

本文利用再分析资料和WRFV3.9模式(Weather Research and Forecasting Model)对2020年7月22-24日发生在黄海海域的一次爆发性气旋进行了研究,并对其演变过程和发展机制进行了详细分析。该气旋22日12 UTC在山东南部生成,入海后开始爆发性发展,最大加深率达到1.2 Bergeron,23日在黄海中部气压降至最低990 hPa左右,24日在韩国登陆。高空强辐散、低层的暖舌结构、水汽输送和下垫面热通量的变化增强了大气斜压性,使其迅速发展。使用WRF模式对气旋进行模拟,涡度的诊断分析表明,大气低层强斜压性主要通过涡度方程的散度项对气旋的发展起作用,对流项在涡度发展旺盛的时刻也有一定影响。海温的敏感性试验表明,海温变化对气旋移动路径和中心气压影响明显。

This study investigated the evolution process and development mechanism of an explosive cyclone over the Huanghai Sea from 22 to 24 July 2020,using reanalysis data and WRFV3.9(Weather Research and Forecasting Model).The cyclone initiated over the southern area of Shandong Province at 12 UTC on 22 July and began to develop explosively after entering the sea,with a maximum deepening rate of 1.2 Bergeron,with its middle pressure dropping to 990 hPa on 23 July,and landed in the Republic of Korea on 24 July.The combination of strong upper-level divergence,low-level warm tongue structure,wet air transport and heat flux change of underlying surface enhanced the atmosphere baroclinicity.WRF model simulated the cyclone successfully,and the vorticity budget analysis indicated that the stretching term played an important role in the cyclone development,while vertical term also had a certain impact on the development.Results of sea surface temperature sensitivity tests suggested that the change of sea surface temperature could obviously affect the development path and intensity of the cyclone.