气候变化领域集成服务门户(CCPortal): Mercury and trace metal wet deposition across five stations in Alaska: Controlling factors; spatial patterns; and source regions

CCPortal

DOI	10.5194/acp-19-6913-2019
	Mercury and trace metal wet deposition across five stations in Alaska: Controlling factors; spatial patterns; and source regions
	Pearson C.; Howard D.; Moore C.; Obrist D.
发表日期	2019
ISSN	16807316
起始页码	6913
结束页码	6929
卷号	19 期号:10
英文摘要	A total of 1360 weeks of mercury (Hg) wet deposition data were collected by the state of Alaska Department of Environmental Conservation and the U.S. National Park Service across five stations spanning up to 8 years. Here, we analyze concentration patterns, source regions, and seasonal and annual Hg deposition loadings across these five sites in Alaska, along with auxiliary trace metals including Cr, Ni, As, and Pb. We found that Hg concentrations in precipitation at the two northernmost stations, Nome (64.5° N) along the coast of the Bering Sea and the inland site of Gates of the Arctic (66.9° N), were statistically higher (average of 5.3 and 5.5 ng L-1, respectively) than those at the two lowest-latitude sites, Kodiak Island (57.7° N, 2.7 ng L-1/and Glacier Bay (58.5° N, 2.6 ng L-1/. These differences were largely explained by different precipitation regimes, with higher precipitation at the lower-latitude stations leading to dilution effects. The highest annual Hg deposition loads were consistently observed at Kodiak Island (4:80 ± 1:04 μg m-2/, while the lowest annual deposition was at Gates of the Arctic (2:11 ± 0:67 μg m-2/. Across all stations and collection years, annual precipitation strongly controlled annual Hg deposition, explaining 73 % of the variability in observed annual Hg deposition. The data further showed that annual Hg deposition loads across all five Alaska sites were consistently among the lowest in the United States, ranking in the lowest 1 % to 5 % of over 99 monitoring stations. Detailed back-trajectory analyses showed diffuse source regions for most Hg deposition sites suggesting largely global or regional Hg sources. One notable exception was Nome, where we found increased Hg contributions from the western Pacific Ocean downwind of East Asia. Analysis of other trace elements (As, Cr, Cu, Ni, Pb, Se, Zn) from Dutch Harbor, Nome, and Kodiak Island showed generally higher trace metal concentrations at the northern station Nome compared to Kodiak Island further to the south, with concentrations at Dutch Harbor falling in between. Across all sites, we find two distinct groups of correlating elements: Cr and Ni and As and Pb. We attribute these associations to possibly different source origins, whereby sources of Ni and Cr may be derived from crustal (e.g., dust) sources while As and Pb may include long-range transport of anthropogenic pollution. Hg was not strongly associated with either of these two groups. © 2019 Author(s).
语种	英语
scopus关键词	anthropogenic source; concentration (composition); long range transport; mercury (element); precipitation (chemistry); spatial variation; trace metal; wet deposition; Alaska; Aleutian Islands; Bering Sea; Dutch Harbor; Fox Islands; Kodiak Island; Nome; Pacific Ocean; Unalaska Island; United States
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/144384
作者单位	Division of Hydrologic Sciences, Desert Research Institute, Reno, NV, United States; Department of Environmental Earth, and Atmospheric Sciences, University of Massachusetts-Lowell, Lowell, MA, United States; Division of Atmospheric Sciences, Desert Research Institute, Reno, NV, United States; Gas Technology Institute, Des Plaines, IL, United States
推荐引用方式 GB/T 7714	Pearson C.,Howard D.,Moore C.,et al. Mercury and trace metal wet deposition across five stations in Alaska: Controlling factors; spatial patterns; and source regions[J],2019,19(10).
APA	Pearson C.,Howard D.,Moore C.,&Obrist D..(2019).Mercury and trace metal wet deposition across five stations in Alaska: Controlling factors; spatial patterns; and source regions.Atmospheric Chemistry and Physics,19(10).
MLA	Pearson C.,et al."Mercury and trace metal wet deposition across five stations in Alaska: Controlling factors; spatial patterns; and source regions".Atmospheric Chemistry and Physics 19.10(2019).