کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5752791 1620306 2017 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Meteorological effects on Hg wet deposition in a forested site in the Adirondack region of New York during 2000-2015
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علم هواشناسی
پیش نمایش صفحه اول مقاله
Meteorological effects on Hg wet deposition in a forested site in the Adirondack region of New York during 2000-2015
چکیده انگلیسی


- Declines in annual Hg wet deposition and VWM precipitation concentrations but no trends by season at HWF over 2000-2015.
- Predominant influence of NAO on Hg wet deposition in spring and of the position of the U.S. East Coast trough in summer.
- Atmospheric concentrations of oxidized mercury hardly correlated with Hg wet deposition or precipitation concentrations.
- Chemical transport model simulations supported efficient scavenging of oxidized mercury by precipitation in summer.

An analysis of weekly measurement data of mercury (Hg) wet deposition was conducted for Huntington Wildlife Forest (HWF), a forest ecosystem in Upstate New York and a biological Hg hotspot, during 2000-2015. Annual accumulated Hg wet deposition flux was found to decrease at a rate of −0.13 μg m−2 yr−1 (2% yr−1) (p = 0.09), and volume weighted mean (VWM) Hg precipitation concentrations at −0.14 ng L−1 yr−1 (2.5% yr−1) (p = 0.00). In examining data by season, no trends were identified for the two variables. It was found that the North Atlantic Oscillation (NAO) affected Hg wet deposition predominantly in spring, as did the position of the U.S. East Coast trough in summer, which suggests different dominant mechanisms driving Hg wet deposition in different seasons. The impacts of such large scale circulation processes were facilitated via variations in precipitation amounts. This was manifested in spring 2011 with the strongest positive phase of NAO, resulting in the wettest spring with the largest Hg wet deposition flux, and in summer 2007 with the U.S. East Coast trough positioned the farthest out over the Atlantic Ocean, causing the driest summer with the lowest Hg wet deposition flux of the study period. Extreme precipitation amounts in spring could singularly drive the overall long-term trend in Hg wet deposition whereas in summer other factors could just be as important. Similar mechanisms were thought to control the long term variations of Hg wet deposition and precipitation concentrations in all seasons but summer as indicated in their significant correlation in all but summer. Atmospheric concentrations of gaseous oxidized mercury (GOM) and particulate borne mercury (PBM) at HWF over 2009-2015 hardly exhibited correlations with Hg wet deposition or precipitation concentrations. Chemical transport model simulations strongly supported efficient scavenging of oxidized Hg by precipitation resulting in the lowest concentration of GOM in the warm season despite the supposedly largest GOM production. Our findings suggest that over the long run climate change could play an important role in atmospheric deposition of Hg into ecosystems facilitated by precipitation amounts, which is closely linked to variations in large scale circulation.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Atmospheric Environment - Volume 168, November 2017, Pages 90-100
نویسندگان
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