超强台风梅花(1109)强度异常减弱成因分析

文章应用中央气象台日常业务中台风强度分析和预报资料、ECMWF再分析资料和NOAA海表热容量反演资料诊断分析了2011年第9号超强台风梅花的强度变化.结果表明,虽然黑潮区域海表面温度较高,海洋热力条件以及相应感热和潜热通量的增加确实为“梅花”增强创造了可能,但是这些有利条件并没有使得“梅花”像预计的那样加强,其主要原因是:“梅花”东北侧高层有强冷空气下沉贯通整层,冷平流在低层侵入台风中心,破坏了台风结构,阻碍了热量向上输送；另一方面环境风垂直切变较大,使得热量不能集中以维持暖心结构.因为环境场中冷平流和垂直风切变的变化,不利于能量输送和集中,是“梅花”强度减弱的主要原因.

Analysis on the Intensity Change in an Abnormal Weakening of Super Typhoon Muifa

Super Typhoon Muifa (1109) got enhanced and weakened twice during its 12 d lifetime. The intensity was predicted stronger during 3-7 August because the high SST of Kuroshio was considered. In this paper, comprehensive and quantitative diagnostic analyses on main factors affecting typhoon intensity are performed. The results suggest that though the ocean thermal conditions are certainly favorable for the typhoon, the ambient field conditions, both the cold air advection and the ambient vertical wind shear, are unfavorable. The negative feedback which well matches the process is the main cause of the weakening.