沙尘天气对我国北方城市大气环境质量的影响

Influence of Dust Storms on Urban Atmospheric Environmental Quality in Northern China

采用2001—2006年沙尘天气的统计数据以及城市空气污染指数(API),分析了沙尘天气对沙尘源区和影响区代表城市的空气质量影响,并分析了2005—2007年兰州和北京春季沙尘天气与非沙尘天气下气溶胶光学厚度与波长指数的变化特征.结果表明:近些年沙尘天气呈先减少后略微增加但总体呈缓慢下降的趋势;春季沙尘天气加重了城市大气污染,对沙尘源区内代表城市的影响超过了区域本底污染指数的50%,使兰州、银川、呼和浩特和包头的春季非沙尘天气API平均值分别增加了64%,53%,86%和90%;使影响区内代表城市,如北京、天津、太原、石家庄、沈阳、济南、西安和郑州的春季非沙尘天气API平均值分别增加了85%,62%,49%,57%,29%,41%,27%和45%;沙尘天气使城市大气气溶胶光学厚度升高,气溶胶波长指数降低.

This paper discussed and analyzed the effect of dust storms on urban air quality in both sand source and affected regions on the basis of statistical data of dust storm events from 2001 to 2006 and the air pollution index（API） data.Furthermore,the aerosol optical depth and angstrom exponent change characteristics were studied in dust-sand weather and non-dust-sand weather in Lanzhou and Beijing from 2005 to 2007.The research results show that the frequency of dust storms reduced slowly in recent years（it reduced at first,and then increased a bit）,and the dust storms aggravated the atmospheric pollution.The influence of the dust storms on the source regions surpassed half of the regional background pollution levels.The average API in spring dust weather of Lanzhou,Yinchuan,Hohhot and Baotou increased 64%,53%,86% and 90%,respectively,while the API of Beijing,Tianjin,Taiyuan,Shijiazhuang,Shenyang,Jinan,Xi＇an and Zhengzhou increased 85%,62%,49%,57%,29%,41%,27% and 45%,respectively.In addition,the aerosol optical depth increased and the angstrom exponent decreased obviously when dust storms occurred.