摘要
20 0 1年 4月底 5月初北京地区出现了一次以浮尘天气为主 ,夹杂轻雾、雷阵雨、烟幕等复杂天气过程的持续重污染事件 ,给北京地区的生产和生活带来了较大的影响。文章主要从天气形势上分析了北京浮尘天气形成的原因和持续空气污染的气象条件。结果表明 ,此次过程是由于高空冷涡发展东移 ,蒙古气旋发展和地面冷锋移动经过蒙古国南部和华北北部等干燥、疏松的地表形成扬沙、沙尘暴 ,大量的细小沙尘粒子随高空偏西气流携带而至北京 ,形成浮尘天气。本地低空处于弱辐合区 ,层结稳定 ,风速小、逆温频繁 ,这些均不利于沙尘粒子和本地污染物的扩散 ,导致连续可吸入颗粒物重污染的形成。
From April 30 to May 5, 2001, Beijing experienced a continuous floating dust and heavy air pollution event. The main causes and the weather situation of the event are analyzed. The results show that a cold vortex at the upper level developed while moving eastward and a cold front on the surface moved across the dry and loose areas in the southern Mongolia and North China, thus resulted in the blowing dust or sand-dust storm. A large amount of fine dust particles moved to Beijing with the upper-level westerly flow and then floating dusts formed over Beijing. At the same time, Beijing was located at the convergence zone and had a stable stratification, small wind speed and frequent inversions in the weather charts. These were unfavorable to the local dust particle and pollutant diffusion; therefore, dust particles were gradually cumulated and heavy air pollution occurred.
出处
《气象科技》
北大核心
2004年第6期420-424,共5页
Meteorological Science and Technology
基金
科技部公益类项目 2 0 0 1DIB2 0 10 3
北京市科委 95 5 3 0 0 60 0项目资助
