| 引用本文: | 彭宵璁，郭子雍，阳宇翔，傅玉珍，孙伟，胡晓东，张国华，毕新慧，王新明.2023.华南地区大气传输过程中黑碳的湿清除比例及其来源的影响[J].地球环境学报,14(2):207-215 |
| PENG Xiaocong, GUO Ziyong, YANG Yuxiang, FU Yuzhen, SUN Wei, HU Xiaodong, ZHANG Guohua, BI Xinhui, WANG Xinming.2023.The wet removal ratio of black carbon during atmospheric transport in South China and the influence of its sources[J].Journal of Earth Environment,14(2):207-215 |
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| 摘要: |
| 黑碳（black carbon，BC）的湿清除对其大气寿命和环境气候效应的评估至关重要。本研究使用黑碳仪（Aethalometer，AE-33）在南岭地区对BC开展了三次观测，结合指数衰减方程评估了传输过程中累计降雨量（accumulated precipitation along the trajectory，APT）对华南地区BC传输效率的影响。此外，将BC来源区分为生物质燃烧源（biomass burning，BB）和化石燃料燃烧源（fossil fuel burning，FF），探讨了不同排放源BC湿清除比例（wet scavenging ratio，WSR）的差异。结果表明：基于指数衰减方程结果和WSR的结果指出华南地区的BC受到湿清除的影响要明显大于日韩等偏远地区，可能反映了更高拟合的BC老化程度。APT在5—30 mm范围内的增加对BC的湿清除有显著的影响。不同来源BC的WSR存在显著差异：BCBB的WSR（44%—62%）高于BCFF（35%—54%），可能反映生物质燃烧排放的BC老化后具有更高的吸湿性。该研究结果有助于深入对实际大气中BC的湿清除及其影响因素的认识，并为模型模拟提供实测数据验证。 |
| 关键词: 黑碳 华南地区 湿清除 来源解析 |
| DOI：10.7515/JEE222048 |
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| 基金项目:国家自然科学基金项目（42192514，42077322） |
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| The wet removal ratio of black carbon during atmospheric transport in South China and the influence of its sources |
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PENG Xiaocong, GUO Ziyong, YANG Yuxiang, FU Yuzhen, SUN Wei, HU Xiaodong, ZHANG Guohua, BI Xinhui, WANG Xinming
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1. State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
2. University of Chinese Academy of Sciences, Beijing 100049, China
3. CAS Center for Excellence in Deep Earth Science, Guangzhou 510640, China
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| Abstract: |
| Background, aim, and scope Black carbon (BC) is a primary emission product from incomplete combustion of fossil fuel and biomass fuel. The wet scavenging of BC strongly affects the lifetime of BC and thus changes the distribution and diffusion of BC in the atmosphere. However, the understanding of the wet scavenging of BC and its influencing factors is still limited. In order to investigate the wet scavenging ratio (WSR) of BC and its influence factors, we performed on-line measurements of BC at Mt. Tianjing (a.s.l., 1690 m), a background area in South China during three different observation periods. Materials and methods The light absorption coefficient of BC was measured by an Aethalometer. Based on such data set, the concentration of BC, the contribution of different sources (i.e., biomass burning (BB) and fossil fuel burning (FF)) can be derived. Combined with the carbon monoxide (CO) concentration, backward trajectory and accumulated precipitation along the trajectory (APT), the wet scavenging ratio of BC, BCBB and BCFF was evaluated using an exponential decay equation. Results The overall average ΔCBC/ΔCOC in Mt. Tianjing were 1.7±1.6, 5.0±4.3, and 1.1±0.8 in May 2017, May 2018 and Apr. 2021. BCFF contributes 82%±6%, 73%±13% and 73%±9%, and BCBB contributes 18%±6%, 27%±13% and 27%±9% during three observation periods, respectively. The wet scavenging ratios (WSR) of BC during three observation periods were 53%, 49% and 38%, respectively. The WSR of BCBB and BCFF during the three observation periods were 58%, 54%, 62%, 39%, 44% and 35%. Discussion During the three observation periods, the source emission contribution of BC was kept relatively stable with fossil fuel as the main source. ΔCBC/ΔCOC has a negative correlation with APT. Fitting with the exponential decay equation, increasing APT in the range of 5—30 mm poses the most significant effect on the wet scavenging of BC. Based on the equation fitting parameters, it is pointed out that the BC in South China is significantly affected by wet removal than in the background areas of Japan and South Korea, which may reflect a higher degree of BC aging. There were significant differences in the W SR of BC from different sources: the WSR of BCBB (44%—62%) was higher than that of BCFF (35%—54%), which may reflect the higher hygroscopicity of BC emitted from biomass combustion after aging. Conclusions The fossil fuel burning is the main contribution of BC sources during observation periods. BC is significantly affected by wet removal and the wet scavenging ratio of BCBB is higher than BCFF in the Nanling area. Recommendations and perspectives The results are helpful to better understand the wet scavenging of BC and its influencing factors in the atmosphere, and provide observational data for model validation. |
| Key words: black carbon South China wet removal source apportionment |
