2017～2018年荆州城区空气质量分布及重污染天气特征分析

利用2017年1月至2018年12月荆州城区3个国家环境空气质量监测点的污染物监测数据和荆州国家气象站地面气象要素观测数据，采用统计学方法，对荆州城区空气质量分布及重污染过程天气特征进行了初步分析，结果表明:空气污染综合指数冬季最高，春秋季次之，夏季最低; PM2.5、PM10、CO和NO2的浓度在上午和傍晚至上半夜其浓度较高，SO2的浓度只在上午6～8时出现一次高峰，在傍晚有一次弱的回升，O3浓度在正午前后大幅上升。研究重度污染时次的气象要素特征，发现:88.6%以上的重度污染时次，其相对湿度都在60%以上;荆州重度污染时次以NNE风向最多，占比28.9%，风速频率最高的区间为1.1～3.0m/s，占比55.8%，其次是0.0～1.0m/s，占比30.5%;重度污染有93.9%是发生在无降水的时次，5.3%发生在2mm以下的弱降水时次。重度污染发生时次里，能见度在3000m以下的占83%; 64.3%的重度污染日，当日最小能见度在1 000m以下。结合环流背景与气象条件，对2017～2018年出现的8次重污染过程进行了分析，将荆州重度污染分为大气静稳型、弱冷空气型和混合型三种类型。影...

Analysis of the Distribution of Air Quality and Characteristics of Heavy Polluted Weather in Jingzhou City in 2017 and 2018

Based on the pollutant monitoring data from three national ambient air quality monitoring points in Jingzhou urban area from January 2017 to December 2018 and ground meteorological elements observation data from Jingzhou National Meteorological Station,using statistical methods,this paper analyzed the air quality distribution and weather characteristics of heavy pollution process in Jingzhou urban area.The results showed that the comprehensive air pollution index was highest in winter,followed by spring and autumn,and the lowest in summer.The concentrations of PM2.5,PM10,CO and NO2 were higher in the morning and evening until midnight.The concentration of SO2 only peaked once at 6-8 in the morning,and there was a weakly rise in the evening.The O3 concentration rose sharply around noon.Studying the characteristics of meteorological elements of heavy pollution times,it is found that the relative humidity of more than 88.6%of the heavy pollution times was more than 60%;NNE wind direction was the most during severe pollution in Jingzhou,accounting for 28.9%,and the highest wind speed frequency Range was 1.1~3.0m/s,accounting for 55.8%,followed by 0.0~1.0m/s,accounting for 30.5%.93.9%of heavy pollution occurred when there was no precipitation,and 5.3%occurred in weak precipitation below 2mm.When severe pollution occurred,visibilities below 3000m accounted for 83%;64.3%of severe pollution days had the minimum visibility below 1000m.Combined with the circulation background and meteorological conditions,8 heavy pollution processes t occurred in 2017~2018 were analyzed,and the heavy pollution in Jingzhou was divided into three types:static and stable atmosphere,weak cold air and mixed.There are many factors that affect air quality.This paper mainly analyzed the characteristics of local meteorological elements and the laws of atmospheric circulation in Jingzhou.The research results can provide the consulting services of meteorological decision-making for the prevention and control of air pollution in Jingzhou City,and can also provide technical support for the prediction of local ambient air quality.