Chemical characterization of wintertime aerosols over the Arabian Sea: Impact of marine sources and long-range transport
Chemical characterization of wintertime aerosols over the Arabian Sea: Impact of marine sources and long-range transport
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DOI：
10.1016/j.atmosenv.2020.117749
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发表时间：
2020-10
影响因子：
5
通讯作者：
P. Bikkina;V. Sarma;K. Kawamura;S. Bikkina;B. Kunwar;C. K. Sherin
中科院分区：
文献类型：
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作者：
P. Bikkina;V. Sarma;K. Kawamura;S. Bikkina;B. Kunwar;C. K. Sherin
我们研究了冬季巡航期间沿阿拉伯海东海岸收集的总悬浮颗粒（TSP）样本的组成特征（SS379: 2018年12月6日至24日），以了解陆源空气污染物的影响程度。对17份TSP样品进行了水溶性无机碳（WSIS）、元素碳（EC）、有机碳（OC）和水溶性有机碳（WSOC）的分析。向后的气团轨迹和基于卫星的火灾计数揭示了印度-恒河平原和印度南部生物质燃烧排放的远程传输的影响。人为SO42−(82-97%)是最丰富的WSIS，其次是Na+和/或NH4+。环境EC负荷（0.5-2.4 μg m−3）和OC/EC比率（2.5-10.5）高于化石燃料燃烧源的通常预期。NO3−/非海盐SO42−的低质量比（0.08-0.49），以及nss-K+/EC（0.14-1.18）和WSOC/OC（0.30-0.74）的高质量比，突出了煤燃烧和生物质燃烧排放在阿拉伯海空气污染物区域涌入中的重要性。多元线性回归分析表明，海盐组分（Na+、Cl−和Mg2+）、碳质组分（OC、EC和WSOC）和人为WSIS （NH4+和SO42−）之间存在较强的相关性。此外，我们利用基于最小r平方技术的初级OC/EC比在EC-示踪剂方法中估计了二级有机碳（SOC）对OC（7-61%）和TSP质量（0.7-11%）的贡献。总体而言，TSP的组成特征为颗粒物有机质（21±10%）、EC（2.3±1.1%）、人为WSIS（21±9%）和包括粉尘在内的未知组分（43±15%）。该研究对理解大陆流出物中次生无机和有机气溶胶的演化性质具有重要意义。
We examined here the compositional characteristics of total suspended particulate (TSP) samples collected along the east coast of the Arabian Sea during a winter cruise (SS379: 6–24 December 2018) to understand the extent of influence of air pollutants from terrestrial sources. The TSP samples (N = 17) were analyzed for water-soluble inorganic species (WSIS), elemental carbon (EC), organic carbon (OC) and water-soluble organic carbon (WSOC). Backward air mass trajectories and satellite-based fire counts revealed an influence of long-range transport of biomass burning emissions in the Indo-Gangetic Plain and southern India. Anthropogenic (82–97%) SO42−is the most abundant WSIS followed by Na+and/or NH4+. Ambient EC loadings (0.5–2.4 μg m−3) and OC/EC ratios (2.5–10.5) are higher than usually expected for fossil-fuel combustion sources. Low mass ratios of NO3−/non-sea-salt SO42−(0.08–0.49), as well as high ratios of nss-K+/EC (0.14–1.18) and WSOC/OC (0.30–0.74), highlight the significance of coal combustion and biomass burning emissions in the regional influx of air pollutants to the Arabian Sea. The multiple linear regression analysis has indicated strong correlations among sea salt components (Na+, Cl−and Mg2+), carbonaceous components (OC, EC and WSOC), and anthropogenic WSIS (NH4+and SO42−). Furthermore, we used minimum R-squared technique based primary OC/EC ratio in the EC-tracer method to estimate the contribution of secondary organic carbon (SOC) to OC (7–61%) and TSP mass (0.7–11%). Overall, the composition of TSP is characterized by 21 ± 10% of particulate organic matter, 2.3 ± 1.1% of EC, 21 ± 9% of anthropogenic WSIS and 43 ± 15% of unidentified fraction including dust. This study has implications for understanding the evolving nature of secondary inorganic and organic aerosols in the continental outflows.