京津冀4次重度污染过程的气象要素分析

Meteorological Element Analysis of Four Severe Pollution Processes in Beijing-Tianjin-Hebei Region

利用2014年京津冀地区4次重度污染过程中的AQI数据及相关气象资料,分析了4次重度污染过程中相对湿度、平均气温、平均风速和海平面气压的一些特征。结果发现:京津冀中南部是重度污染发生的主要区域,是这4次过程中的共同点;就目前的排放水平而言,相对湿度持续高于60%时是出现重度污染并维持的重要指标;平均气温对于出现重度污染过程的指示意义不足;无论是在冬季、春季还是秋季出现的重度污染过程,平均风速小于2.0 m·s^(-1)是污染物堆积的必要条件;海平面气压的高压和低压区位置对于污染范围有着明显影响,高压区位于京津冀地区的偏东位置时,有利于该地区污染出现或维持重度水平。

In this paper,using the AQI data and associated meteorological data,the characteristics of relative humidity,average temperature,average wind speed and sea level pressure were analyzed for four severe pollution processes occurred in Beijing-Tianjin-Hebei region in 2014. The results show that central south of Beijing-Tianjin-Hebei region is the heaviest pollution area,which is the common ground of the four severe pollution processes. According to the current level of emissions,higher relative humidity（ 〉60%） is one of key contributors to the occurrence of severe pollution. The average temperature has no sufficient indication meaning for the occurrence of severe pollution. Additionally,the average wind speed was less than 2. 0 m·s^-1was one of the most important contributors to the accumulation of pollutants,either the pollution episodes occurred in winter,spring or autumn. The positions of high and low pressure of sea level pressure played a significant role in the pollution range. When the high pressure was located in east of Beijing-Tianjin-Hebei region,it is beneficial to the occurring and maintenance of heavy pollution.