边界层参数化方案对南海秋季台风“莎莉嘉”(2016)模拟的影响

THE INFLUENCE OF BOUNDARY LAYER PARAMETERIZATION SCHEMES ON AUTUMN TYPHOON SARIKA(2016) IN SOUTH CHINA SEA

利用美国中尺度数值模式WRF,选取两个局地(QNSE、MYJ)闭合和两个非局地(YSU、ACM2)闭合的边界层参数化方案对台风"莎莉嘉"(2016)进行了4组模拟试验,结果表明,不同边界层方案对台风路径影响较小,但对台风强度和结构有明显的影响,就本个例研究而言,非局地闭合边界层方案明显优于局地闭合边界层方案。台风强度的差异是热力和动力共同作用的影响。局地闭合方案模拟的地表焓通量、水汽通量和动量通量更大,台风偏强;局地闭合方案模拟的边界层高度更高、边界层顶的夹卷过程更强、垂直混合更强、台风暖心结构更强,从而台风也更强。台风强度的差异和台风结构的变化密切相关。

In this article,through the American mesoscale numerical model WRF,four simulation tests of Typhoon Sarika(2016)have been carried out by selecting two local closure boundary layer parameterization schemes(QNSE,MYJ)and two non-local closure boundary layer parameterization schemes(YSU,ACM2).The results indicated that different boundary layer schemes have little influence on the typhoon track,but have a significant influence on its strength and structure.As far as the case study in this article,the non-local closure boundary layer schemes are obviously superior to the local ones.The difference in typhoon strength is influenced by the combined action of thermal and dynamic conditions.The earth surface enthalpy flux,water vapor flux and momentum flux of the local closure boundary layer schemes are stronger,so that the typhoon will be stronger;for the simulations by the local closure boundary layer schemes,boundary layer altitudes are higher,entrainment processes at the top of boundary layer are stronger,vertical mixes are stronger,and typhoon warm core structures are stronger,so that the typhoon will be stronger.The difference in typhoon strength is closely related to the variation of typhoon structure.