2010年春季沙尘天气对北京市空气质量的影响及其天气类型分析

The Effects of Dust Weather on Air Quality and its Synoptic Type in Spring 2010 of Beijing

利用2010年3—5月北京市市区以及北京西北部、西部和东部3个不同方位边界的空气质量自动监测站监测数据,结合气象资料和激光雷达观测数据,分析了春季外来沙尘对北京市空气质量的影响。研究结果表明:2010年春季北京市出现15次外来沙尘天气,外来沙尘输送对北京市空气质量的影响天数为21 d,直接造成15 d空气质量超标,最严重的一次API指数达到最大值500。沙尘的天气形势特征以及输送路径的不同,对北京市空气质量的影响有明显差异。当低压中心过境时,沙尘天气影响最重,颗粒物浓度显著上升,气态污染物迅速下降,沙尘呈现自西北向东南输送的特征;低压底部过境与低压中心过境类似,但是沙尘强度略弱;除此之外,沙尘回流也可以直接造成北京市空气质量超标,颗粒物浓度和气态污染物浓度均表现出上升的变化趋势。

Since 2010′s,Beijing is still frequently affected by external dust.This paper used the air quality online monitoring data of the urban station,northwest,western and eastern sites of Beijing city,combined with meteorological data and observed data of laser radar,analyzed the effect of dust weather on air quality in Spring in Beijing.The results implies that： Beijing is affected by external dust weather in Spring of 2010 for 15 times.The transport of outside dust affect Beijing for 21 days,among which Air Pollutant Index were beyond the standard for 15 days.The API of the severest case reached 500,the maximum of the index.The significant impact of dust storms on air quality in Beijing has been found,which is determined by the dust waether conditions and the transport path.For the type of low pressure center after the high pressure,air quality is the worst and the transmitted route of dust is from northwest to southeast.The effects of the type of low-pressure bottom is similar with that of low pressure center while the effect is weaker.In addition,the dust return could directly induce that air quality is beyond the API standard.