【摘要】 本文用MM5模式模拟了0307号台风“伊布都”影响广西的暴雨过程.其结果表明:副高西侧偏南风急流的加强为广西大范围的暴雨天气创造了有利条件,台风环境风场的不对称结构导致其暴雨的不对称分布.孟加拉湾至中南半岛一带维持强盛的西南风急流,为台风南部维持强的涡度中心提供了大尺度的背景场.涡度空间分布的不对称是造成台风南部暴雨的主要原因.本次桂南暴雨的水汽源来自孟加拉湾,中南半岛水汽输送通道明显;过程前期螺旋度高低空负、正垂直螺旋度配置十分有利于系统自身的发展及暴雨的维持;对流不稳定度的增强和湿斜压涡度的发展,导致中低层湿位涡的增强,有利于降水加剧.更多还原

【Abstract】 This paper used MM5 to simulate the process of 0307 Typhoon Imbudo that influenced Guangxi.It showed that the strength of south jet in west of the subtropical high pressure benefited the rainstorm and the asymmetry of rainstorm was from the asymmetry of typhoon wind field.The lasting strong southwest lower-level jet provided large-scale atmospheric circulation for upkeep of strong vorticity in the south of typhoon.The asymmetry of vorticity field was the leading cause of the heavy rainfall in the south of typhoon.The moisture of the rainstorm came from bengal gulf and there were distinct moisture transportation channel in Indo-China Peninsula.The most fields of physical variables were closely related to heavy rainfall between the higher and lower layers of rainstorm positive,where negative helicity column benefited its developing and the rainstorm maintaining.The strength of convective instability and the strengthened moist potential vorticity occurred at the low layers,which contributes to typhoon rainfall.更多还原