J4 ›› 2007, Vol. 25 ›› Issue (3): 17-22.

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General Circulation Characteristic Before Beg inn ing of Yunnan Ra iny Season

L IU Yu1 , ZHAO Erxu2 , HUANGWei1 , ZHU Yong1 , TAO Yun1   

  1. 1. Clim ate Center of Yunnan, Kunm ing 650034, China; 2 M eteorological Science and Technology Services Center of Yunnan, Kunm ing 650034, China
  • Received:2007-08-08 Revised:2007-09-02 Online:2007-09-30 Published:2007-09-30

春末初夏异常环流对云南雨季开始期的影响

刘 瑜1 ,赵尔旭2 ,黄 玮1 ,朱 勇1 ,陶 云1   

  1. 1. 云南省气候中心,云南 昆明 650034; 2. 云南省气象科技服务中心,云南 昆明 650034
  • 作者简介:刘瑜(1958 - ) ,女,汉族,云南人,高级工程师,主要从事短期气候预测和研究工作. E - mail: cqkly@163. com

Abstract:

Results of wavelet analysis show the beginning of Yunnan rainy season is on early stage in interdecadal variation. In the year of 2006 (2005) , the beginning of Yunnan rainy season is very early( late). Based on comparative analysis on the general circulation of the two very different years, it is found that the main difference of general circulation characteristic for the early ( late) beginning of Yunnan rainy season is in Ap ril, namely, the boundary between the easterly and westerly wind at the level of 200 hPa lies northward ( southward) ; the general circulation ofmid - high latitude at the level of 500 hPa is ( isn’t) helpful for cold air to move southward; the equatorial zonalwesterly wind of the North India Ocean at the level of 850 hPa is stronger (weaker) than that in normal years, and the convection around Sumatra is stronger (weaker) than that in normal years.

Key words: rainy season of Yunnan, general circulation, zonalwind, convection

摘要:

通过小波分析表明云南目前处于雨季开始期偏早的年代际变化中。2006 (2005)年是云南雨季开始特早(晚)的异常年,把这2个雨季开始期相反的极端异常年进行对比分析,发现云南雨季偏早(晚)的4月主要环流特征差异是: 200 hPa对流层东西风交界线比多年平均偏北(南) ; 500 hPa中高纬环流有(不)利于冷空气南下; 850 hPa北印度洋赤道纬向西风较常年偏强(弱) ,孟加拉湾南部苏门答腊岛附近的对流较常年偏强(弱)

关键词: 云南雨季, 环流, 纬向风, 对流

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