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Titel |
Ten-year trends of atmospheric mercury in the high Arctic compared to Canadian sub-Arctic and mid-latitude sites |
VerfasserIn |
A. S. Cole, A. Steffen, K. A. Pfaffhuber, T. Berg, M. Pilote, L. Poissant, R. Tordon, H. Hung |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 3 ; Nr. 13, no. 3 (2013-02-07), S.1535-1545 |
Datensatznummer |
250017645
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Publikation (Nr.) |
copernicus.org/acp-13-1535-2013.pdf |
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Zusammenfassung |
Global emissions of mercury continue to change at the same time as the
Arctic is experiencing ongoing climatic changes. Continuous monitoring of
atmospheric mercury provides important information about long-term trends in
the balance between transport, chemistry, and deposition of this pollutant
in the Arctic atmosphere. Ten-year records of total gaseous mercury (TGM)
from 2000 to 2009 were analyzed from two high Arctic sites at Alert
(Nunavut, Canada) and Zeppelin Station (Svalbard, Norway); one sub-Arctic
site at Kuujjuarapik (Nunavik, Québec, Canada); and three temperate
Canadian sites at St. Anicet (Québec), Kejimkujik (Nova Scotia) and
Egbert (Ontario). Five of the six sites examined showed a decreasing trend
over this time period. Overall trend estimates at high latitude sites were:
−0.9% yr−1 (95% confidence limits: −1.4, 0) at Alert and no
trend (−0.5, +0.7) at Zeppelin Station. Faster decreases were
observed at the remainder of the sites: −2.1% yr−1 (−3.1, −1.1) at
Kuujjuarapik, −1.9% yr−1 (−2.1, −1.8) at St. Anicet, −1.6% yr−1 (−2.4, −1.0)
at Kejimkujik and −2.2% yr−1 (−2.8, −1.7) at
Egbert. Trends at the sub-Arctic and mid-latitude sites agree with reported
decreases in background TGM concentration since 1996 at Mace Head, Ireland,
and Cape Point, South Africa, but conflict with estimates showing an
increase in global anthropogenic emissions over a similar period. Trends in
TGM at the two high Arctic sites were not only less negative (or neutral)
overall but much more variable by season. Possible reasons for differences
in seasonal and overall trends at the Arctic sites compared to those at
lower latitudes are discussed, as well as implications for the Arctic
mercury cycle. The first calculations of multi-year trends in reactive
gaseous mercury (RGM) and total particulate mercury (TPM) at Alert were also
performed, indicating increases from 2002 to 2009 in both RGM and TPM in the
spring when concentrations are highest. |
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