State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China.
Sci Total Environ. 2022 Aug 1;832:154929. doi: 10.1016/j.scitotenv.2022.154929. Epub 2022 Mar 31.
Particulate chloride is a major component of sea salt particles and plays a key role in atmospheric chemistry. Anthropogenic pollutants over the northeastern Asia can be transported to the adjacent seas through the northwest monsoon, which profoundly influences the chloride chemistry over the seas. In this study, spatial distribution of particulate chloride and its sources over the Chinese seas were investigated based on shipboard particle samplings especially online Single Particle Aerosol Mass Spectrometer (SPAMS) over Bohai Sea, North Yellow Sea, and South Yellow Sea (SYS) during a cruise in November 2012. A strong north-to-south (N-S) gradience in marine aerosol composition was found. The Cl/Na ratios in PM and single particle composition by SPAMS indicated remarkable chloride enrichment in marine aerosol in the north (Bohai Sea), while depletion in southern SYS. The results of size distribution showed that particulate chloride had higher concentration in coarse particles, while the Cl/Na ratio was much higher in submicron particles. In the north (38-40°N), biomass burning, carbonaceous, and Pb-rich type particles had high fractions in all chloride-containing particles identified by SPAMS (on average 66%). Combining chemical composition with back trajectory, it was found that fine-mode chloride enrichment in the north was mainly due to anthropogenic emission especially coal combustion and biomass burning from northern China. However, the high fine-mode chloride depletion in the south (32-34°N) was probably due to acid replacement by sulfate in aged aerosol during atmospheric transport. Our new findings reveal that marine aerosol in Chinese seas would show a clear N-S pattern of more fresh and anthropogenic enriched particles in the north, but more aged aerosol in the south during the East Asia Winter Monsoon, which provides new insights for the quantitative assessment of anthropogenic impact on marine aerosol and future modeling study.
颗粒态氯是海盐颗粒的主要成分，在大气化学中起着关键作用。东北亚地区的人为污染物可以通过西北季风输送到邻近海域，这对海洋的氯化学产生了深远的影响。本研究在 2012 年 11 月的一次航次中，通过船上颗粒物采样，特别是在渤海、北黄海和南黄海（SYS）进行的在线单颗粒气溶胶质谱仪（SPAMS）采样，调查了中国海域颗粒态氯的空间分布及其来源。发现海洋气溶胶组成存在强烈的南北梯度。PM 中的 Cl/Na 比值和 SPAMS 给出的单颗粒组成表明，北部（渤海）海洋气溶胶中氯的富集程度显著，而南部 SYS 则出现氯的亏损。粒径分布的结果表明，颗粒态氯在粗粒子中的浓度较高，而 Cl/Na 比值在亚微米粒子中要高得多。在北部（38-40°N），生物质燃烧、含碳和富 Pb 型颗粒在 SPAMS 鉴定的所有含氯颗粒中占较高比例（平均为 66%）。结合化学成分和后向轨迹，发现北部细模态氯的富集主要是由于人为排放，特别是来自中国北方的煤燃烧和生物质燃烧。然而，南部（32-34°N）细模态氯的高损耗可能是由于在大气传输过程中，老化气溶胶中的硫酸盐对酸的替代作用。我们的新发现表明，在东亚冬季风期间，中国海域的海洋气溶胶将呈现出一种明显的南北模式，即北部有更多的新鲜和人为富集的颗粒，而南部则有更多的老化气溶胶，这为定量评估人为对海洋气溶胶的影响和未来的建模研究提供了新的见解。
