Mercury and trace metal wet deposition across five stations in Alaska: controlling factors, spatial patterns, and source regions
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...
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ftdoajarticles:oai:doaj.org/article:8dee09ea107b4d0a88c2a88f0a09b314 2023-05-15T15:03:39+02:00 Mercury and trace metal wet deposition across five stations in Alaska: controlling factors, spatial patterns, and source regions C. Pearson D. Howard C. Moore D. Obrist 2019-05-01T00:00:00Z https://doi.org/10.5194/acp-19-6913-2019 https://doaj.org/article/8dee09ea107b4d0a88c2a88f0a09b314 EN eng Copernicus Publications https://www.atmos-chem-phys.net/19/6913/2019/acp-19-6913-2019.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-19-6913-2019 1680-7316 1680-7324 https://doaj.org/article/8dee09ea107b4d0a88c2a88f0a09b314 Atmospheric Chemistry and Physics, Vol 19, Pp 6913-6929 (2019) Physics QC1-999 Chemistry QD1-999 article 2019 ftdoajarticles https://doi.org/10.5194/acp-19-6913-2019 2022-12-31T03:35:47Z 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 µ g m −2 ) , while the lowest annual deposition was at Gates of the Arctic ( 2.11±0.67 µ g 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 ... Article in Journal/Newspaper Arctic Bering Sea glacier Kodiak Nome Alaska Directory of Open Access Journals: DOAJ Articles Arctic Bering Sea Glacier Bay Pacific Atmospheric Chemistry and Physics 19 10 6913 6929 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Physics QC1-999 Chemistry QD1-999 |
spellingShingle |
Physics QC1-999 Chemistry QD1-999 C. Pearson D. Howard C. Moore D. Obrist Mercury and trace metal wet deposition across five stations in Alaska: controlling factors, spatial patterns, and source regions |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
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 µ g m −2 ) , while the lowest annual deposition was at Gates of the Arctic ( 2.11±0.67 µ g 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 ... |
format |
Article in Journal/Newspaper |
author |
C. Pearson D. Howard C. Moore D. Obrist |
author_facet |
C. Pearson D. Howard C. Moore D. Obrist |
author_sort |
C. Pearson |
title |
Mercury and trace metal wet deposition across five stations in Alaska: controlling factors, spatial patterns, and source regions |
title_short |
Mercury and trace metal wet deposition across five stations in Alaska: controlling factors, spatial patterns, and source regions |
title_full |
Mercury and trace metal wet deposition across five stations in Alaska: controlling factors, spatial patterns, and source regions |
title_fullStr |
Mercury and trace metal wet deposition across five stations in Alaska: controlling factors, spatial patterns, and source regions |
title_full_unstemmed |
Mercury and trace metal wet deposition across five stations in Alaska: controlling factors, spatial patterns, and source regions |
title_sort |
mercury and trace metal wet deposition across five stations in alaska: controlling factors, spatial patterns, and source regions |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/acp-19-6913-2019 https://doaj.org/article/8dee09ea107b4d0a88c2a88f0a09b314 |
geographic |
Arctic Bering Sea Glacier Bay Pacific |
geographic_facet |
Arctic Bering Sea Glacier Bay Pacific |
genre |
Arctic Bering Sea glacier Kodiak Nome Alaska |
genre_facet |
Arctic Bering Sea glacier Kodiak Nome Alaska |
op_source |
Atmospheric Chemistry and Physics, Vol 19, Pp 6913-6929 (2019) |
op_relation |
https://www.atmos-chem-phys.net/19/6913/2019/acp-19-6913-2019.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-19-6913-2019 1680-7316 1680-7324 https://doaj.org/article/8dee09ea107b4d0a88c2a88f0a09b314 |
op_doi |
https://doi.org/10.5194/acp-19-6913-2019 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
19 |
container_issue |
10 |
container_start_page |
6913 |
op_container_end_page |
6929 |
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1766335503929442304 |