Study on the Dynamic Characteristics of an Eastward-offshore Mesoscale Vortex along the Meiyu-Baiu Front  

作　　者：YU Fei FU Shen-Ming ZHAO Si-Xiong SUN Jian-Hua 

机构地区：[1]International Center for Climate and Environment Sciences, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China [2]Graduate University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Atmospheric and Oceanic Science Letters》2012年第5期360-366,共7页大气和海洋科学快报（英文版）

基　　金：supported by the National Basic Research program of China (No. 2009CB421401);the National Natural Science Foundation of China (No. 40930951)

摘　　要：The eastward-moving Meiyu-Baiu frontal mesoscale vortices (MBFMVs) appear frequently and often cause heavy rainfall events along their tracks. A move-off-shore MBFMV was selected to enhance our understanding of this type of vortex. Synoptic analyses indicate that the MBFMV is a type of meso-α vortex and mainly occurs in the lower troposphere. A short wave trough near the coastline is highly favorable for the formation, sustainment, and displacement of the MBFMV. Vorticity budgets indicate that at lower levels of the MBFMV, convergence is the dominant factor for the increase of positive vorticity, and at high levels of the MBFMV, the vertical transportation associated with convective activities is the most important factor. The hori-zontal transportation was the main factor decreasing the positive vorticity. The land and sea environments are crucial to the evolution of the MBFMV. The characteristics of the Meiyu-Baiu Front (MBF) are also vital to the variation of the vortex.The eastward-moving Meiyu-Baiu frontal mesoscale vortices （MBFMVs） appear frequently and often cause heavy rainfall events along their tracks. A move-off-shore MBFMV was selected to enhance our understanding of this type of vortex. Synoptic analyses indicate that the MBFMV is a type of meso-α vortex and mainly occurs in the lower troposphere. A short wave trough near the coastline is highly favorable for the for- mation, sustainment, and displacement of the MBFMV. Vorticity budgets indicate that at lower levels of the MBFMV, convergence is the dominant factor for the in- crease of positive vorticity, and at high levels of the MBFMV, the vertical transportation associated with convective activities is the most important factor. The hori- zontal transportation was the main factor decreasing the positive vorticity. The land and sea environments are crucial to the evolution of the MBFMV. The characteristics of the Meiyu-Baiu Front （MBF） are also vital to the variation of the vortex.

关 键 词：Meiyu-Baiu Front mesoscale vortex vortic-ity budget 

分 类 号：P722.7[天文地球—海洋科学] P426.62