气候变化领域集成服务门户(CCPortal): Speciated atmospheric mercury and sea-air exchange of gaseous mercury in the South China Sea

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DOI	10.5194/acp-19-10111-2019
	Speciated atmospheric mercury and sea-air exchange of gaseous mercury in the South China Sea
	Wang C.; Wang Z.; Hui F.; Zhang X.
发表日期	2019
ISSN	16807316
起始页码	10111
结束页码	10127
卷号	19 期号:15
英文摘要	The characteristics of the reactive gaseous mercury (RGM) and particulate mercury (HgP) in the marine boundary layer (MBL) are poorly understood, due in part to sparse data from the sea and ocean. Gaseous elemental Hg (GEM), RGM, and size-fractionated HgP in the marine atmosphere, and dissolved gaseous Hg (DGM) in surface seawater, were determined in the South China Sea (SCS) during an oceanographic expedition (3-28 September 2015). The mean concentrations of GEM, RGM, and HgP 2:5 were 1:52±0:32 ng m-3, 6:1±5:8 pg m-3, and 3:2±1:8 pg m-3, respectively. A low GEM level indicated that the SCS suffered less influence from fresh emissions, which could be due to the majority of air masses coming from the open oceans, as modeled by back trajectories. Atmospheric reactive Hg (RGM C HgP 2:5) represented less than 1 % of total atmospheric Hg, indicating that atmospheric Hg existed mainly as GEM in the MBL. The GEM and RGM concentrations in the northern SCS (1:73±0:40 ng m-3 and 7:1±1:4 pg m-3, respectively) were significantly higher than those in the western SCS (1:41 ± 0:26 ng m-3 and 3:8 ± 0:7 pg m-3), and the HgP 2:5 and HgP 10 levels (8.3 and 24.4 pg m-3) in the Pearl River estuary (PRE) were 0.5-6.0 times higher than those in the open waters of the SCS, suggesting that the PRE was polluted to some extent. The size distribution of HgP in PM10 was observed to be three-modal, with peaks around < 0.4, 0.7-1.1, and 5.8-9.0 μ m, respectively, but the coarse modal was the dominant size, especially in the open SCS. There was no significant diurnal pattern of GEM and HgP 2:5, but we found that the mean RGM concentration was significantly higher in daytime (8:0 ± 5:5 pg m-3) than in nighttime (2:2 ± 2:7 pg m-3), mainly due to the influence of solar radiation. In the northern SCS, the DGM concentrations in the nearshore area (40-55 pg L-1) were about twice as high as those in the open sea, but this pattern was not significant in the western SCS. The sea-air exchange fluxes of Hg0 in the SCS varied from 0.40 to 12.71 ng m-2 h-1 with a mean value of 4:99 ± 3:32 ng m-2 h-1. The annual emission flux of Hg0 from the SCS to the atmosphere was estimated to be 159.6 t yr-1, accounting for about 5.54 % of the global Hg0 oceanic evasion, although the SCS only represents 1.0 % of the global ocean area. Additionally, the annual dry deposition flux of atmospheric reactive Hg represented more than 18 % of the annual evasion flux of Hg0, and therefore the dry deposition of atmospheric reactive Hg was an important pathway for the input of atmospheric Hg to the SCS. © 2019 Author(s).
语种	英语
scopus关键词	air-sea interaction; boundary layer; concentration (composition); dry deposition; marine atmosphere; mercury (element); particulate matter; solar radiation; speciation (chemistry); Pacific Ocean; South China Sea
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/144221
作者单位	Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing, China; College of Geosciences, China University of Petroleum (Beijing), 18 Fuxue Road, Beijing, China
推荐引用方式 GB/T 7714	Wang C.,Wang Z.,Hui F.,et al. Speciated atmospheric mercury and sea-air exchange of gaseous mercury in the South China Sea[J],2019,19(15).
APA	Wang C.,Wang Z.,Hui F.,&Zhang X..(2019).Speciated atmospheric mercury and sea-air exchange of gaseous mercury in the South China Sea.Atmospheric Chemistry and Physics,19(15).
MLA	Wang C.,et al."Speciated atmospheric mercury and sea-air exchange of gaseous mercury in the South China Sea".Atmospheric Chemistry and Physics 19.15(2019).