上海地区一次典型连续浮尘天气过程分析

Analysis of a typical dust event in Shanghai

研究分析了2011年5月1~4日上海地区一次典型的连续浮尘天气过程.利用微脉冲激光雷达数据资料反演得到的气溶胶消光系数和垂直廓线,结合地面气象数据和气溶胶观测资料以及卫星遥感资料,初步研究了此次连续浮尘过程的传输特征和形成的主要原因.结果表明,5月1日的浮尘过程以PM2.5的影响为主,而5月2~4日为回流浮尘过程,PM2.5比重较5月1日下降.外源性输入、垂直风场分布和大气层结变化为浮尘天气的发生和维持创造了有利条件.研究还发现,在此次浮尘的气溶胶大气消光作用中,其散射贡献大于吸收作用.

A dust event which occurred in Shanghai during May 1-4, 2011 was investigated. The main features of dust transportation as well as formation were preliminary examined using data of atmosphere extinction coefficients and vertical profiles retrieved from the ground-based Micro Pulse LIDAR （MPL_4B）, synoptic meteorological factors, aerosol concentrations and satellite remote sensing products. The results show that the dusty day on 1st May was mainly influenced by PM2.5, while the dusty day during May 2-4 was influeced by returning process of dust, in which the PMz5 concentration decreased compared to that on 1st May. Dust from remote source, vertical wind distribution, and atmospheric stratification change provide favorable conditions for the formation and maintenance of the dust event. Moreover, as to the role of aerosol in atmosphere extinction, the scattering effect was more evident than absorption.