摘要
大气消光系数湿度订正是气溶胶吸湿性研究的重要内容,也是利用卫星气溶胶光学厚度(AOD)产品反演近地面颗粒物质量浓度的关键技术环节。基于成都市2016年1月至12月的逐时PM_(2.5)质量浓度、大气能见度、相对湿度(RH)观测数据,首先,深入探讨了大气消光系数与颗粒物质量浓度之间的统计关系及其对RH变化的响应特征,发现在RH小于90%时,单位质量大气消光系数均服从对数正态分布,并进一步指出该分布函数的形状参数和尺度参数均随RH的增加呈现出波动型增长。其次,以干燥环境条件下(RH小于等于40%)单位质量大气消光系数对数正态分布参数为基准,通过数学变换消除湿度变化对单位质量大气消光系数概率分布参数的影响,据此提出了大气消光系数湿度订正的原理和计算流程。最后,对该原理的适用性进行研究,结果表明,订正后大气消光系数反演得到的PM_(2.5)质量浓度与实际PM_(2.5)质量浓度相关系数为0.90,显著优于气溶胶散射吸湿增长因子法的湿度订正结果。
Humidity correction on atmospheric extinction coefficient is an important component of aerosol hygroscopicity research,which is also a key technical link for determining the mass concentration of near-ground particulate matter retrieved by satellite aerosol optical depth(AOD).Based on hourly PM_(2.5) mass concentration,atmospheric visibility,and relative humidity(RH)data collected in Chengdu from January to December 2016,the statistical relationship between the atmospheric extinction coefficient and particulate matter mass concentration,as well as its response characteristics with RH variation,are discussed in detail.The atmospheric extinction coefficient per unit mass follows a log-normal distribution when RH is less than 90%,and the shape and scale parameters of the distribution function exhibit a fluctuating growth as RH increases.Second,based on the log-normal distribution parameter of atmospheric extinction coefficient per unit mass under dry environmental conditions(RH≤40%),the effect of humidity change on the probability distribution parameter of atmospheric extinction coefficient per unit mass is eliminated via mathematical transformation.Consequently,the principle and flow chart of humidity correction are proposed for the atmospheric extinction coefficient.Finally,the applicability based on the principle demonstrates that the correlation coefficient of PM_(2.5) mass concentration calculated by corrected atmospheric extinction coefficient and actual PM_(2.5) mass concentration is up to 0.90,significantly improving the corresponding humidity correction result using aerosol scattering hygroscopic growth factor method.
作者
李川
倪长健
杨萌
李昕翼
任至涵
Li Chuan;Ni Changjian;Yang Meng;Li Xinyi;Ren Zhihan(School of Atmospheric Sciences,Chengdu University of Information Technology,Chengdu,Sichuan 610225,China;Plateau Atmosphere and Environment Key Laboratory of Sichuan Province,Chengdu,Sichuan 610225,China;Chengdu Meteorological Office,Chengdu,Sichuan 611130,China)
出处
《激光与光电子学进展》
CSCD
北大核心
2021年第19期110-117,共8页
Laser & Optoelectronics Progress
基金
国家重点研发计划(2018YFC0214004,2018YFC1506006)
四川省科技厅应用基础研发项目(2021YJ0314)。
关键词
大气光学
大气消光系数
对数正态分布
概率分布参数
湿度订正
适用性
atmospheric optics
atmospheric extinction coefficient
log-normal distribution
probability distribution parameter
humidity correction
applicability
