秸秆燃烧气溶胶的气象反馈及其棕碳吸光效应  

Meteorological feedback and brown carbon absorption effect of straw burning aerosols

作　　者：王璐瑶 张磊[1,3] 安兴琴[1,2] 王格慧[4] WANG Lu-yao;ZHANG Lei;AN Xing-qin;WANG Ge-hui(State Key Laboratory of Disaster Weather,Chinese Academy of Meteorological Sciences,Beijing 100081,China;Meteorological Impact and Risk Research Center,Chinese Academy of Meteorological Sciences,Beijing 100081,China;CMA.Key Laboratory of Atmospheric Sounding-KLAs,Beijing 100081,China;School of Geographical Sciences,East China Normal University,Shanghai 200062,China)

机构地区：[1]中国气象科学研究院灾害天气国家重点实验室,北京100081 [2]中国气象科学研究院气象影响与风险研究中心,北京100081 [3]中国气象局大气化学重点开放实验室,北京100081 [4]华东师范大学地理科学学院,上海200062

出　　处：《中国环境科学》2024年第3期1212-1224,共13页China Environmental Science

基　　金：国家自然科学基金资助项目(42130704,41975173,42207134)。

摘　　要：本文利用WRF-Chem模式模拟研究了2013年6月华北地区秸秆燃烧排放气溶胶的气象效应,并对秸秆燃烧产生的吸收性有机气溶胶(即棕碳或BrC)的光吸收效应进行分析.设置4组敏感性试验,通过与AERONET观测结果对比分析了BrC对光吸收的影响.结果表明:模式较好再现了研究时段内各变量变化;在不考虑BrC吸收的情况下,秸秆燃烧产生的气溶胶在主要的农业产区造成地表短波辐射的减弱,月平均值减弱约12.42W/m2,且造成近地面降温而2km以上高空增温,其中近地面温度降幅为0.12~3.64℃,致使边界层趋于稳定,垂直扩散能力减弱;气压整体升高,正变压中心与火点密集区域重合.同时,秸秆燃烧引发近地面较强的风辐散,抑制海洋高湿气团向秸秆燃烧区域的水平输送.在考虑BrC的吸收作用后,光学参数的模拟效果得到了一定提升,AAOD模拟值与观测值的拟合线性斜率由0.47升至0.53,AOD斜率值由0.19升至0.21.生物质燃烧排放BrC对气溶胶消光的影响显著,如AAOD与AOD均出现不同程度的上升.Straw burning is a major source of biomass combustion in North China,significantly impacting air quality.Using the WRF-Chem model,we simulated the meteorological effects of aerosol emissions from straw burning in June 2013 and conducted a preliminary analysis of the light-absorbing properties of brown carbon(BrC)produced during straw burning.We conducted four sensitivity experiments,comparing the impact of BrC on light absorption with AERONET observations.Results showed that the model effectively captured variations in various parameters during the study period.Without considering BrC absorption,straw burning led to a reduction in surface shortwave radiation,causing a monthly average decrease of approximately 12.42 W·m-2 in major agricultural regions.This resulted in near-surface cooling,warming above 2km,and reduced vertical diffusion,stabilizing the boundary layer.There was an overall increase in atmospheric pressure,coinciding with fire hotspot areas.Straw burning also induced strong near-surface wind divergence,hindering the horizontal transport of moist air masses from the ocean.Considering BrC absorption,the simulation of optical parameters significantly improved.The linear fit slope between simulated Absorption Aerosol Optical Depth(AAOD)and observed values increased from 0.47 to 0.53,and the slope of Aerosol Optical Depth(AOD)increased from 0.19 to 0.21.Biomass burning emissions of BrC had a notable impact on aerosol extinction,leading to increased AAOD and AOD to varying degrees.

关 键 词：生物质燃烧 BrC 光吸收 WRF-Chem模式 华北地区 

分 类 号：X513[环境科学与工程—环境工程]