期刊
ATMOSPHERIC ENVIRONMENT
卷 168, 期 -, 页码 90-100出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.atmosenv.2017.08.058
关键词
Huntington Wildlife Forest; Mercury wet deposition; Mercury precipitation concentration; Large scale circulation; Climate; NAO; US East Coast Trough
资金
- New York State Energy Research and Development Authority (NYSERDA)
- U.S. Environmental Protection Agency [83521501]
- National Science Foundation [ACI-1548562]
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 mu g 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. (C) 2017 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据