Title Trends in long-term gaseous mercury observations in the Arctic and effects of temperature and other atmospheric conditions
Author Cole, A.S.; Steffen, A.
Author Affil Cole, A.S., Environment Canada, Air Quality Research Division, Toronto, ON, Canada
Source Atmospheric Chemistry and Physics, 10(10), p.4661-4672, . Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1680- 7316
Publication Date 2010
Notes In English. Part of special issue no. 189, Chemistry, emission, and transport of atmospheric mercury (CETAM), edited by Ebinghaus, R., Pirrone, N, and Kim, K. H., http://www.atmos-chem- phys.net/special_issue189.html; published in Atmospheric Chemistry and Physics Discussions: 16 December 2009, http://www.atmos-chem-phys- discuss.net/9/27167/2009/acpd-9-27167- 2009.html ; accessed in May, 2011. 49 refs. GeoRef Acc. No: 310048
Index Terms climate; climatic change; ice; metals; meteorology; ozone; statistical analysis; temperature; wind (meteorology); Canada-- Alert; Russia--Amderma; Arctic Ocean; Arctic region; Russia--Nenets; Canada--Nunavut; Alert Canada; Amderma Russian Federation; Arctic Oscillation; Arkhangelsk Russian Federation; atmosphere; atmospheric transport; bromine; Canada; climate change; Commonwealth of Independent States; correlation coefficient; depletion; deposition; Europe; gaseous phase; halogens; mercury; Nenets Russian Federation; North Atlantic Oscillation; Nunavut; Russian Federation; sea ice; seasonal variations; transport; winds
Abstract Gaseous elemental mercury (GEM) measurements at Alert, Canada, from 1995 to 2007 were analyzed for statistical time trends and for correlations with meteorological and climate data. A significant decreasing trend in annual GEM concentration is reported at Alert, with an estimated slope of -0.0086 ng m-3 yr-1 (-0.6% yr-1) over this 13-year period. It is shown that there has been a shift in the month of minimum mean GEM concentration from May to April due to a change in the timing of springtime atmospheric mercury depletion events (AMDEs). These AMDEs are found to decrease with increasing local temperature within each month, both at Alert and at Amderma, Russia. These results support the temperature dependence suggested by previous experimental results and theoretical kinetic calculations on both bromine generation and mercury oxidation and highlight the potential for changes in Arctic mercury chemistry with climate. A correlation between total monthly AMDEs at Alert and the Polar/Eurasian Teleconnection Index was observed only in March, perhaps due to higher GEM inputs in early spring in those years with a weak polar vortex. A correlation of AMDEs at Alert with wind direction supports the origin of mercury depletion events over the Arctic Ocean, in agreement with a previous trajectory study of ozone depletion events. Interannual variability in total monthly depletion event frequency at Alert does not appear to correlate significantly with total or first- year northern hemispheric sea ice area or with other major teleconnection patterns. Nor do AMDEs at either Alert or Amderma correlate with local wind speed, as might be expected if depletion events are sustained by stable, low-turbulence atmospheric conditions. The data presented here--both the change in timing of depletion events and their relationship with temperature--can be used as additional constraints to improve the ability of models to predict the cycling and deposition of mercury in the Arctic.
URL http://www.atmos-chem-phys.net/10/4661/2010/acp-10-4661-2010.pdf
Publication Type journal article
Record ID 65006804