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中国沙漠 ›› 1996, Vol. 16 ›› Issue (4): 351-355.

• 研究论文 • 上一篇    下一篇

宁夏强沙尘暴形成机制的探索和研究

张玉林, 赵光平, 杨淑萍   

  1. 宁夏回族自治区气象台, 银川 750002
  • 收稿日期:1995-12-20 修回日期:1996-07-15 出版日期:1996-12-20 发布日期:1996-12-20

PROBING INTO THE FORMING MECHANISM OF POWERFUL SANDSTORM IN NINGXIA

Zhang Yuling, Zhao Guangping, Yang Shuping   

  1. Ningxia Hui Autonomous Region Metorological Observation, Yinchuan 750002
  • Received:1995-12-20 Revised:1996-07-15 Online:1996-12-20 Published:1996-12-20

摘要: 宁夏沙尘暴天气主要发生于每年的3~5月, 其中4月份出现频数最高, 是此类天气发生及预报的关键期。影响宁夏的强沙尘暴天气的强冷空气主要取道于乌鲁木齐-哈密-野马街-酒泉_贺兰山西侧这一沙漠通道上; 而当强冷空气急行东南下时, 地面冷高压不断发展、加强和整体东移是产生强沙尘暴天气的必要条件。春季西北地区变化剧烈的热力条件是中小尺度天气系统发展和上下层冷暖空气交换的主要物理原因之一, 同时也是强沙尘暴、沙尘暴天气日变化明显的关键所在。诊断分析认为, 正是在极有利的大尺度环境、高空干冷急流和强垂直风速、风向切变及强热力不稳定层结条件下, 引起锋区前后的巨大压、温梯度。在动量下传和梯度偏差风及高空强大下击暴流的共同作用下, 使近地层风速陡升, 掀起地表沙尘, 形成强沙尘暴天气

关键词: 宁夏, 强沙尘暴, 形成机制

Abstract: The Sandstorms in Ningxia take place mainly in the time from march to May, with high frequency in April which is the key period to forecast sandstorms coming. The reasons of winding sandstorms lie in the following aspects:(1) while the cold air mass is heading southeast speedly through the passing way of Urumqi-Hami-Ye majie-Jiuquan-the west side of Alxa Mountain, the cold high over ground is developed and intensified;(2) under the condition of unstable heat stratification of Spring in the northwest of China, the mid-small scale of atmospheric circulation generates and develops to lead to the great pressure and temperature gradients before and behind front. Influenced by these two aspects of factors, the wind speed near ground climbs up fastly and sand-dusts are blown up.

Key words: Ningxia, Powerful sandstorm, Forming mechanism