基于地基太阳光度计观测的长安区气溶胶光学特性变化及其与颗粒物浓度的关系  

Aerosol Optical Characteristics with Ground-based Measurements via Sun Photometer and Its Relationship with PM Particle Concentration in Chang’an

作　　者：郑玉蓉 王旭红[1,2,3] 崔思颖 冯子豪 张秀 刘康 ZHENG Yu-rong;WANG Xu-hong;CUI Si-ying;FENG Zi-hao;ZHANG Xiu;LIU Kang(College of Urban and Environmental Science,Northwest University,Xi'an710127,China;Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity,Northwest University,Xi'an 710127,China;Shaanxi Xi’an Urban Forest Ecosystem Research Station,Northwest University,Xi'an 710127,China)

机构地区：[1]西北大学城市与环境学院,西安710127 [2]陕西省地表系统与环境承载力重点实验室,西安710127 [3]陕西西安城市生态系统定位观测研究站,西安710127

出　　处：《环境科学》2022年第7期3494-3507,共14页Environmental Science

基　　金：国家自然科学基金项目(41971387,41071271);陕西省自然科学基础研究计划项目(2020JM-430)。

摘　　要：气溶胶地基观测数据和颗粒物浓度数据的同步定量评估可为了解长安区大气污染的垂直分布特征,制定合理的大气污染控制提供更有效的依据.基于CE-318太阳光度计观测数据,分析了2018年10月~2021年4月西安市长安区月均和季均气溶胶光学特性分布和变化特征,结合近地面颗粒物浓度数据,分析了不同季节、不同污染程度下气溶胶光学厚度(AOD)对颗粒物浓度的响应.结果表明:(1)观测期间长安区AOD季节变化分明:秋季(1.02)>冬季(1.00)>夏季(0.63)>春季(0.47);AOD月度、年际差异大,2019年AOD(0.51)略高于2020年(0.48).(2)整个观测期间长安区气溶胶主控模态存在明显的季节、月度差异,从春季到冬季气溶胶主控模态逐渐从粗模态向细模态转变;2019年气溶胶主控模态的季节变化与整个观测时段类似,2020年各季节气溶胶Angstrom波长指数(Angstrom)分布稳定,气溶胶粒子均以粗模态的形式存在;整个观测时段来看长安区气溶胶类型以混合型气溶胶为主.(3)AOD和Angstrom的关系存在明显的季节差异,春季大气污染以粗模态的气溶胶粒子为主导;夏季的局部污染由粗、细模态的气溶胶粒子共同导致的,明显污染时,以细模态粒子为主导;秋冬两季AOD-Angstrom特征分布类似,局部污染时,以粗模态的气溶胶粒子为主导,明显污染时,细模态的气溶胶粒子处于主导地位.(4)长安区PM_(2.5)和PM_(10)浓度的月度变化趋势一致,最大值均出现在1月,最小值均在夏季出现;PM_(2.5)和PM_(10)浓度的季节变化明显,冬季最高.(5)不同季节、不同污染程度下AOD和颗粒物浓度均呈正相关关系,但相关程度存在差异,AOD与PM_(2.5)浓度的相关性大于与PM_(10)浓度的相关性;秋冬两季AOD与颗粒物浓度的相关性均大于春夏两季;污染天气下AOD与颗粒物浓度的相关性更大;颗粒物浓度是AOD变化最重要的决定因素,其次为相对湿度,是对长安区AOD变化解释率�The simultaneous quantitative investigation of aerosol ground observation data and particle concentration data is important for a better understanding of the vertical distribution characteristics of air pollution and formulating reasonable air pollution control measures in Chang’an,Xi’an.CE-318 measurements from October 2018 to April 2021 were systematically analyzed to reveal the seasonal and yearly variations in atmospheric aerosols in Chang’an.Then,the relationship between AOD and particle concentration in different seasons and different pollution degrees was explored.The obtained results were as follows:(1)the seasonal variation in AOD in Chang’an was determined,whereby autumn(1.02)>winter(1.00)>summer(0.63)>spring(0.47).Distinct monthly and inter-annual differences in AOD were observed,showing that the annual average of AOD in 2019 was higher than that in 2020.(2)Obvious seasonal and monthly differences in aerosol main control modes were observed;the dominant mode of aerosols gradually changed from coarse mode to fine mode from spring to winter.The seasonal variation in the main control mode of aerosols in 2019 was similar to that in the whole observation period.The seasonal aerosol Angstrom wavelength index(Angstrom)was evenly distributed in 2020,and aerosol particles existed in coarse mode form.Generally speaking,the aerosol type in Chang’an was mostly mixed aerosol throughout the whole observation period.(3)Significant seasonal variations in the relationship between AOD and Angstrom was shown,in which the air pollution in spring was dominated by coarse mode aerosol particles.The local pollution in summer was caused by coarse and fine mode aerosol particles,and the fine mode particles were dominant when the pollution was obvious.The characteristic distribution of Angstrom in autumn and winter was similar;in case of local pollution,the coarse mode aerosol particles were dominant,and in case of obvious pollution,the fine mode aerosol particles were dominant.(4)The monthly concentration variation tr

关 键 词：气溶胶光学厚度(AOD) 太阳光度计 颗粒物浓度 时序变化 长安区 

分 类 号：X122[环境科学与工程—环境科学] X513