| 广西背景大气中生物质燃烧对碳质气溶胶组成和吸光性的影响 |
| 摘要点击 1335 全文点击 331 投稿时间：2023-01-12 修订日期：2023-02-23 |
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| 中文关键词 生物质燃烧(BB) 左旋葡聚糖(LG) 吸光系数(babs) 碳质气溶胶 贝叶斯混合模型 |
| 英文关键词 biomass burning (BB) levoglucosan (LG) light absorbing coefficient (babs) carbonaceous aerosol Bayesian mixing model |
| 作者 | 单位 | E-mail | | 吴星麒 | 南京信息工程大学应用气象学院, 南京 210044
南京信息工程大学大气环境中心, 教育部气候与环境变化国际合作联合实验室, 南京 210044 | 202219000002@nuist.edu.cn | | 曹芳 | 南京信息工程大学应用气象学院, 南京 210044
南京信息工程大学大气环境中心, 教育部气候与环境变化国际合作联合实验室, 南京 210044 | caofangle@163.com | | 洪一航 | 南京信息工程大学应用气象学院, 南京 210044
南京信息工程大学大气环境中心, 教育部气候与环境变化国际合作联合实验室, 南京 210044 | | | 邢佳莉 | 南京信息工程大学应用气象学院, 南京 210044
南京信息工程大学大气环境中心, 教育部气候与环境变化国际合作联合实验室, 南京 210044 | |
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| 中文摘要 |
| 碳质气溶胶是大气细颗粒物（PM2.5）的重要组成部分，对空气质量、人体健康和气候变化均有重要影响.针对生物质燃烧（BB）这一碳质气溶胶的重要来源，于2017年11月至2018年10月在广西壮族自治区背景地区采集了PM2.5样品，分析了样品中的碳质组成、糖类化合物和水溶性棕色碳（BrC）的吸光系数（babs）.使用气团老化指数（AAM）校正LG浓度以消除LG降解带来的影响，进而结合贝叶斯混合模型与分子示踪剂法量化了BB对有机碳（OC）的贡献率，并通过相关性分析法探讨了BrC的可能来源.结果表明，研究期间AAM指数平均值为0.40±0.28，表示LG存在光化学降解过程.农作物秸秆是广西地区最主要的生物质燃料类型，在未考虑LG降解下，全年玉米、水稻和甘蔗秸秆焚烧排放的OC分别占总OC的22%、23%和18%；考虑LG在大气中的降解后，相对贡献率分别降低至16%、21%和17%.LG的降解会导致BB对OC的贡献率评估被低估，经过AAM指数校正后，全年BB对OC的贡献率平均值为49.0%.水溶性BrC的babs全年的平均值为（8.7±10.7） Mm-1，其中BB、化石燃料燃烧以及初级生物气溶胶排放可能是BrC的重要来源. |
| 英文摘要 |
| Carbonaceous aerosols are an important component of fine particulate matter (PM2.5) in the atmosphere, having great impacts on air quality, human health, and the climate. In this study, PM2.5 samples were collected from November 2017 to October 2018 in a background site of Guangxi Province to investigate the potential impacts of biomass burning, an essential source of carbonaceous aerosols, on carbonaceous aerosols. Further, the composition of carbonaceous aerosols, sugar compounds, and the light absorption coefficient (babs) of water-soluble brown carbon (BrC) were also conducted. Considering the effect of the degradation of atmospheric levoglucosan (LG), the concentration of the corrected LG was quantified using the aging of air masses (AAM) index. Then, the contribution of biomass burning (BB) to organic carbon (OC) [BB-OC] was quantified using the corrected LG-derived molecular tracer method combined with the Bayesian mixing model. Here, we further explored the potential sources of water-soluble BrC using correlation analysis. In this research, the mean AAM index was 0.40±0.28 during the study period, indicating that the atmospheric LG had undergone a photochemical degradation process. The characteristic ratio combined with the Bayesian mixing model indicated that the crop straw (i.e., corn, rice, and sugarcane straw) was the dominant biomass fuel type in the Guangxi Region, contributing 22%, 23%, and 18% of OC without the correction of LG and 16%, 21%, and 17% with the corrected LG concentration, respectively. The neglection of LG degradation led to the underestimation of BB-OC, in which the BB-OC values with and without correction were 49.0% and 21.1%, respectively. Here, the annual mean babs of water-soluble BrC was (8.7±10.7) Mm-1, and its main sources were BB, fossil fuel combustion, and vegetation emission. |
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