杭州市区相对湿度及PM_(2.5)对能见度的影响分析  

The analysis of relative humidity and PM_(2.5) impact on visibility in Hangzhou

作　　者：杜荣光[1] 齐冰[1] 胡德云[1] 李璐[1] 俞布[1] 

机构地区：[1]杭州市气象局,杭州310051

出　　处：《南京大学学报（自然科学版）》2015年第3期473-480,共8页Journal of Nanjing University（Natural Science）

基　　金：国家公益性行业(气象)科研专项(GYHY201206011);杭州市科技局社会发展科研专项(20130533B09)

摘　　要：利用杭州国家基准气候站2011—2013年的环境气象资料,对相对湿度(relative humidity,RH)、颗粒物质量浓度与能见度(V)之间的对应关系进行统计分析,结果表明:杭州市区颗粒物的吸湿性增加比较明显,当RH≥80%时,相对湿度对能见度的影响十分明显,而在干霾过程中,PM2.5质量浓度对能见度的影响程度大于相对湿度对能见度的影响程度.其次是能见度与PM2.5质量浓度呈指数对应关系,RH<80%时的相关性好于RH≥80%时的相关性;三是PM2.5浓度的减少对能见度的改善效果有不同的阶段性,PM2.5浓度从150μg·m-3降到75μg·m-3时,其质量浓度的减少对能见度的改善效果不很明显,当PM2.5质量浓度小于50μg·m-3时,能见度随PM2.5质量浓度的降低而快速上升.此外,从高时间分辨率气象资料可以反映出由于辐射冷却引起的多次雾霾转换过程中能见度变化特征具有很高的相似性.The relationship between atmospheric visibility（V）and its relevant affecting factors,such as the relative humidity（RH）and the mass concentration of particulate matter in Hangzhou from 2012 to 2013is analyzed with statistic method in this paper.The results show that,atmospheric particles in Hangzhou grow obviously through moisture absorption.The relative humidity（RH）has prominent effect on the visibility when it is equal to or greater than 80%,while it has less impact than that of PM2.5concentration on the visibility when itis less than 80%,or in the dry haze process.Secondly,the massconcentration of PM2.5 matter is exponential with the visibility,and a more closed relation is found when RH is less than 80%.Third,impact of PM2.5reduction on visibility shows differently when the PM2.5concentration is varied.That is,when the PM2.5concentration reduces from 150μg·m^-3to 75μg·m^-3,the visibility will not be much improved,while when the PM2.5concentration reduces to the level of less than 50μg·m^-3,it will bevery helpful in the visibility melioration.Furthermore,the characteristics of atmospheric visibility show high identity in fog-haze conversion caused by radiation cooling according to the high temporal resolution meteorological data.

关 键 词：能见度 相对湿度 PM2.5 消光系数 

分 类 号：P427.2[天文地球—大气科学及气象学]