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中国沙漠 ›› 2013, Vol. 33 ›› Issue (5): 1461-1472.DOI: 10.7522/j.issn.1000-694X.2013.00212

• 天气与气候 • 上一篇    下一篇

高空急流对一次强沙尘暴过程沙尘传输的影响

段海霞1, 李耀辉1, 蒲朝霞1,2, 赵建华1, 张 良1   

  1. 1.中国气象局兰州干旱气象研究所 甘肃省(中国气象局)干旱气候变化与减灾重点(开放)实验室, 甘肃 兰州 730020;
    2.犹他大学 大气科学系, 美国 犹他州 盐湖城 84112
  • 收稿日期:2012-08-17 修回日期:2012-12-17 出版日期:2013-09-20 发布日期:2012-12-17

The Influence of High Level Jet on Dust Transportation in a Sandstorm Process

DUAN Hai-xia1, LI Yao-hui1, PU Zhao-xia1,2, ZHAO Jian-hua1, ZHANG Liang1   

  1. 1.Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province/Key Open Laboratory of Climatic Change and Disaster Reduction of China Meteorological Administration, Institute of Arid Meteorology, China Meteorological Administration, Lanzhou 730020, China;
    2.Department of Atmospheric Sciences, University of Utah, Salt Lake City 84112, Utah, USA
  • Received:2012-08-17 Revised:2012-12-17 Online:2013-09-20 Published:2012-12-17

摘要:

使用GRAPES_SDM沙尘暴数值模式,对2011年4月28-30日中国北方强沙尘暴天气进行分析,讨论高空急流在此次过程中对沙尘传输的影响,得出以下结论:(1)GRAPES_SDM沙尘暴模式较好地模拟了此次沙尘暴过程的范围和强沙尘暴中心,整体模拟效果较好;(2)沙尘天气发生时间及移动路径与200 hPa高空急流的加强、移动发展有很好的对应关系;(3)高空强纬向风速的加强能够促使中低层形成垂直环流圈,其下沉支流使高空动量有效下传到近地面,进而在地面形成大风及扬沙和沙尘暴天气,强沙尘暴中心位于此垂直环流圈的下沉支;(4)等熵位涡与高空急流及地面沙尘浓度分布演变有很好的对应关系,等熵位涡位于高空急流北侧,地面沙尘浓度中心位于高空急流出口区、等熵位涡中心西南侧、等值线密集带;高层高值位涡区向下延伸的路径与高空急流北侧纬向风速等值线密集带有非常好的对应关系。本文还通过对高空急流轴线动力、热力结构垂直剖面的分析,探讨了高空急流对大范围沙尘天气影响的可能机制。

关键词: 强沙尘暴过程, 高空急流, GRAPES_SDM沙尘暴模式, 动量下传

Abstract:

Through the simulations of GRAPES_SDM sandstorm model to a strong sandstorm process in north of China during April 28-30 in 2011, the influence of High-Level Jet on dust transportation was analyzed. It was showed that: (1) The GRAPES_SDM model simulated successfully the range and center of the sandstorm process, the total simulation effect was good. (2) The occurrence time and movement path of sand weather were in accordance with the increase and movement of High-Level Jet at 200 hPa. (3) The increase of strong zonal wind speed in high level could brought about the development of vertical circulation cell in mid-low level, and the sinking branch of the circulation cell brought the high-level momentum to near surface, and then the strong wind, sand-blowing and sandstorm appeared. The center of strong sandstorm was at the sinking branch of the vertical circulation cell. (4) The path to underneath of high value region of potential vorticity was coincident relatively with the isoline dense zone of zonal wind in the north of High-Level Jet. Through the analysis on the dynamical and thermal vertical cross-section along High-Level Jet axes, we also discussed the probable mechanism of the influence of High-Level Jet on large range sand weather.

Key words: strong sandstorm process, High-Level Jet, GRAPES_SDM model, momentum transportation downward

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