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中国沙漠 ›› 2014, Vol. 34 ›› Issue (1): 197-205.DOI: 10.7522/j.issn.1000-694X.2013.00300

• 天气与气候 • 上一篇    下一篇

欧亚大气环流对中国北方夏季沙尘天气的影响

康林, 季明霞, 黄建平   

  1. 兰州大学 半干旱气候变化教育部重点实验室, 甘肃 兰州 730000
  • 收稿日期:2013-01-14 修回日期:2013-03-01 出版日期:2014-01-20 发布日期:2014-01-20
  • 作者简介:康林(1986- ),男,四川绵阳人,硕士,主要从事西北干旱气候方面的研究。Email:kl0317@126.com
  • 基金资助:
    国家科技支撑计划项目(2009BAC51B04);国家重大科学研究计划项目(2012CB955301);国家自然科学基金项目(41175134,41305060);兰州大学中央高校基本科研业务费项目(lzujbky-2013-109)资助

Impact of Eurasian Atmospheric Circulation on Dust Events in Summer over Northern China

Kang Lin, Ji Mingxia, Huang Jianping   

  1. Ministry of Education Key Laboratory for Semi-Arid Climate Change, Lanzhou University, Lanzhou 730000, China
  • Received:2013-01-14 Revised:2013-03-01 Online:2014-01-20 Published:2014-01-20
  • Contact: 季明霞,jimx@lzu.edu.cn

摘要: 根据1960-2010年全国701个地面站沙尘天气观测资料分析了中国夏季沙尘天气的空间分布和年际变化,发现南疆和内蒙古两个沙尘源区的夏季沙尘指数51年来均呈现出减小的趋势。通过分析夏季沙尘指数典型高、低值年环流场发现:500 hPa高度场上强烈发展的高原-贝加尔湖平均脊和减弱的东亚大槽,减少了高空低值系统对南疆和内蒙古中西部地区的影响,地面场上“北负南正”的变压场分布使得两个地区西风和西北风减小,最终导致夏季南疆和内蒙古地区沙尘天气减少。沙尘指数高值年时影响两个地区天气系统的差异在于:影响南疆地区的天气系统主要是高空的西路冷空气和地面场上发展的南疆热低压,而影响内蒙古地区的则是北路和偏北路冷空气以及地面场上强烈发展的蒙古-内蒙古热低压。

关键词: 沙尘指数, 500 hPa高度场, 850 hPa风场, 海平面气压场

Abstract: Based on the frequency of dust events in summer from 701 meteorological stations, two dust indices, which are Taklimakan Desert Index (TDI) and the Gobi Desert Index (GDI) were established to characterize the statistical feature of the summer dust occurrence. The two indices both exhibit a sudden decrease in the late 1980s and early 1990s. By analyzing the summer circulation field during the typical strong and weak summer dust index years of Southern Xinjiang and Inner Mongolia regions, we found that the Geopotential height of Mongolia-Inner Mongolia strongly elevated and developed into a ridge of high pressure, Southern Xinjiang and western Inner Mongolia were controlled by the ridge, altitude low value system reducing the influence of the two regions, the intensity of Siberia cold high pressure and the thermal low pressure in East Asian waken was the main mechanism in the Gobi desert region, which caused the less dust events in the Inner Mongolia and Southern Xinjiang.

Key words: dust index, 500 hPa geopotential height field, 850 hPa wind field, sea level pressure field

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