影响云南高原地区的南海西行台风水汽输送特征

Water Vapor Transport Characteristics of South China SeaWestbound Typhoon which Affected Yunnan Plateau

南海西行台风是云南高原地区重要的降水天气系统之一,研究其水汽输送特征为本地降水预报和分析研究提供了前期基础。本文利用2010-2019年10年的南海西行台风样本资料和NCEP再分析数据,研究了影响云南高原地区的南海西行台风水汽输送特征。结果表明:(1)西行登陆台风向云南水汽输送路径主要是东、南、北方三个方向,东侧面水汽输入最大,北侧面水汽输入最小,这两个方向的水汽来源自南海,南侧面水汽输入较东侧面小、比北侧面大,水汽来源自南海和孟加拉湾;(2)东面和南面是两个水汽输入主要方向,北部湾登陆西行台风对云南的影响大于海南岛以东登陆的西行台风;(3)海南岛以东登陆的西行台风东侧面水汽输入大值中心比其他类型台风偏北,南侧面水汽输入分布东西部区域各存在一个相对的大值中心;(4)东侧面北部湾登陆西行台风水汽输入登陆前后6 h达到最大,海南岛以东登陆西行台风稍有滞后,登陆后6~12 h达到最大;(5)南侧面东部区域登陆西行台风水汽输入峰值出现在登陆后12~24 h,南侧面西部区域登陆西行台风水汽输入情况比较复杂,受孟加拉湾与南海两支水汽输送叠加影响。

The South China Sea westbound typhoon is one of the major weather systems which affected the precipitation on the Yunnan plateau.The study of water vapor transport characteristics is the base to the prediction and analysis of precipitation.The study used 10-year's westbound typhoon cases from 2010 to 2019 and appropriate NCEP reanalysis data.The study showed that:(1)The water vapor transported to Yunnan by the westbound typhoon were mainly via three paths,Eastern path,Southern path and Northern path.The Eastern path contributed most of water vapor,less contributed by the Northern path.The water vapor contributed by the Southern path were mixed water vapor from the Bay of Bengal and South China Sea;(2)Themajority of water vapor were from the Eastern path and the Southern path.The westbound It's a little bit complicated for the Southwest side of the Southern path,as it mixed the water vapor from the Bay of Bengal and South China Sea.