武汉市观象台2013-2016年PM_(2.5)质量浓度变化及其与气象因子的相关分析

Variation of PM_(2.5) Mass Concentration and Correlation Analysis With Meteorological Factors in Wuhan Observatory During 2013-2016

基于2013-2016年武汉市观象台PM_(2.5)质量浓度和地面气象要素资料,分析了该地区多年来PM_(2.5)质量浓度变化特征及其与气象因子的相关关系。结果表明:武汉市观象台PM_(2.5)质量浓度年际变化呈持续下降的趋势,但PM_(2.5)和PM_(10)质量浓度的比值持续升高,主要集中在[0.7,1.0)。空气质量污染日数自2013年起逐年减小,优良日数逐年上升。不同季节PM_(2.5)质量浓度存在显著差异,表现为冬季的>春季的>秋季的>夏季的。与背景地区的金沙区域大气本底站的同期观测结果相比发现,两地的PM_(2.5)质量浓度月均值变化趋势基本一致,但武汉市观象台的各月浓度均高于背景地区的,其中1月的增幅最高,为101.0%,9月的最低,为40.3%。由于受到人们出行活动早晚高峰的影响,武汉市观象台PM_(2.5)质量浓度日变化呈典型的双峰单谷型,峰值分别出现在08:00和20:00,谷值出现在15:00,表现出明显的周循环和"周末效应"。PM_(2.5)质量浓度变化与降水量、风速和气温等气象因子的相关分析呈现出季节性差异,其中冬季PM_(2.5)与降水量的相关系数为0.55,冬春季呈显著正相关,夏秋季呈负相关;冬季PM_(2.5)与风速的相关系数为0.68,呈显著正相关,春夏季呈负相关;秋季PM_(2.5)与气温的相关系数为0.37,四季均呈显著正相关。

Based on 2013 -2016 PM2.5 mass concentration and surface meteorological data in Wu-han observatory, the variation characteristics of PM2.5 in this area and its correlation with meteorological factors were analyzed. The results show that annual average PM2.5 mass concentration of Wuhan observato-ry has been decreasing continuously, but the ratio of PM2.5/PM10 rising continuously, mainly in the range of [0. 7,1.0）. Air pollution days reduced and the good grades days raised since 2013. There was a signif-icant difference in PM2.5mass concentration in different seasons, which manifested as in winter 〉 spring 〉 autumn 〉 summer. Compared with the Jinsha region background area, although the monthly average varia-tion trend of PM2.5 mass concentration at Wuhan observatory keep basic consistent with Jinsha area,the monthly average concentration of Wuhan were higher than the background value,the highest one was in January,the increase up to 101.0% ,the minimum one was 40. 3% in September. The Daily variation of PM2.5 mass concentration was mainly influenced by people travel activities in the morning and evening, and showed the typical type of bimodal and single valley, the peaks appeared at 08 ： 00 and 20 ： 00, the valley appeared at 15 ： 00,this also presented an obvious weekly cycle and weekend effectThe correla-tion analyzed between the precipitation, wind speed, temperature and PM2.5 mass concentration showed significant seasonal difference, the correlation coefficient between PM2.5 and precipitation in winter was 0.55,which was significantly positive correlation in winter and spring,negative correlation in the fall and summer. The correlation coefficient between PM2.5 and wind speed in winter was 0. 68, which was signifi-cantly positive correlation in winter, negative in spring and summer. The correlation coefficient between PM2.5 and temperature was 0.37 in autumn,and it was significantly positive correlation in all seasons.