2013年9月大气环流和天气分析

Analysis of the September 2013 Atmospheric Circulation and Weather

2013年9月环流特征如下:极涡分裂,主体位于西半球;里海以北有阻寒形势出现,西太平洋副高强度较常年偏强、位置偏西。全国平均降水量69.3 mm,较常年同期偏多6.1%,华西部分地区秋雨明显,河南北部等地降水量不足常年20%,有中到重度气象干旱;全国平均气温1 6.8℃,较常年同期偏高0.2℃。9月我国的大范围强降水过程有2次,其中一次与热带气旋活动有关。9月共有8个热带气旋在南海和西北太平洋活动,较常年同期平均偏多3个,其中"天兔"是近40年来登陆粤东沿海的最强台风。全国17个省(区、市)发生风雹灾害;我国中东部出现雾霾天气。

The main characteristics of the general atmospheric circulation in September 2013 are as follows. The polar vortex stretches and splits with its main body located at Western Hemisphere and blocking emerging to the north of Caspian Sea. The Northwest Pacific subtropical high is stronger and more westward extended than normal. The monthly mean precipitation amount is 69. 3 mm, which is 6. 1% more than normal. There are a series of notable autumn rainfall processes over western China while moderate-to-severe drought appears in northern Henan with precipitation less than 20% of normal. The monthly mean temperature is 16.8℃, being 0.2℃ higher than normal. There are 2 large-range heavy rainfall processes over China, and one of them is related with tropical cyclone. There are 8 tropical cyclones generated in the which Usagi （1319） is the strongest typhoon that lands at the east coast of recent 40 years. 17 provinces （regions, cities） suffer from severe wind and hail rn China is hit by haze.