img

官方微信

高级检索

中国沙漠 ›› 2008, Vol. 28 ›› Issue (2): 349-356.

• 天气与气候 • 上一篇    下一篇

西北干旱区一次阵风锋天气过程分析

胡文东1; 陶林科2; 杨 侃1,3; 纪晓玲1,3; 丁建军1,3; 杨有林1,2

  

  1. 1.宁夏气象防灾减灾重点实验室, 宁夏 银川 750002; 2.宁夏吴忠市气象局, 宁夏 吴忠 751100;3.宁夏气象台, 宁夏 银川 750002
  • 收稿日期:2006-12-25 修回日期:2007-03-27 出版日期:2008-03-20 发布日期:2008-03-20

Analysis on a Gust Front Event in Arid Area of Northwest China

HU Wen-dong1; TAO Lin-ke2; YANG Kan1,3; JI Xiao-ling1,3; DING Jian-jun1,3; YANG You-lin1,2
  

  1. 1.Key Laboratory of Meteorological Disaster Preventing and Reducing of Ningxia, Yinchuan 750002, China; 2.Wuzhong Meteorological Bureau of Ningxia, Wuzhong 751100, Ningxia, China; 3.Ningxia Meteorological Observatory, Yinchuan 750002, China
  • Received:2006-12-25 Revised:2007-03-27 Online:2008-03-20 Published:2008-03-20

摘要:

利用银川新一代天气雷达观测资料和自动站实况资料,结合本地化非静力平衡中尺度数值预报MM5模式产品,对2004年6月7日银川地区一次区域大风天气过程进行了雷达气象学和中小尺度天气学背景分析。结果表明:这次突发短时大风天气由雷暴强烈下沉气流形成阵风锋引发。阵风锋导致风速增加、气温下降、相对湿度上升。阵风锋在对流云团减弱后仍向前推进,并继续维持30 min左右。阵风锋的长度超过40 km,宽3 km,主体顶高达1 500 m。当时空气层结不稳定,有利于对流运动发展。500 hPa冷空气因重力原因下泻,并与对流垂直环流的下沉气流相结合,是导致强烈下沉气流的根本原因。阵风锋东移过程中,冷气流受下垫面加热作用增暖变性,受地表磨擦而丧失动量;到达贺兰山麓后,环境大气温度随地形升高而下降,阵风锋前后的气温达到平衡而消失。宁夏本地化非静力平衡中尺度数值预报模式对此次阵风锋过程具有较好的模拟能力。

关键词: 阵风锋, 雷达资料, 数值模式产品, 分析

Abstract: The new generation weather radar(CINRAD) data, intensively observed data from automatic meteorological stations and the products of meso-scale numerical model MM5 were used to analyze a gust front event in Yinchuan in arid Northwest China on 7 June 2004 based on the radar meteorological and meso-meteorological theories. The results show that the gust front was triggered by strong down draft and the gust front had caused the increase of wind speed and relative humidity and the decrease of temperature. After the weakening of the convective cloud cluster, the gust front marched on 32 minutes along its previous route. The length of the gust front expanded to more than 40 km and width to 3 km, and with a main body height of 1 500 m. The instable stratification of atmosphere was favorable for the convection. The cold air at 500 hPa rushed down because of the gravity and its combination with the down draft of the vertical circulation of convection were the fundamental reason of violent downing current. As the gust front moving eastward, the cold air was heated by the warm surface and lost it momentum because of the friction, when it climbed the Mt. Helan, the environmental temperature dropped along with the elevation increased, and the gust front disappeared as the temperature before and after the front reached the balance. The local meso-scale numeric model has a good capability to simulate the gust front.

Key words: gust front, Doppler weather radar, products of numerical model MM5, analysis

中图分类号: