Next Article in Journal
Numerical Modeling of Climate-Chemistry Connections: Recent Developments and Future Challenges
Next Article in Special Issue
Total Gaseous Mercury Concentration Measurements at Fort McMurray, Alberta, Canada
Previous Article in Journal
Spatio-Temporal Analysis of Droughts in Semi-Arid Regions by Using Meteorological Drought Indices
Article Menu

Export Article

Open AccessArticle
Atmosphere 2013, 4(2), 113-131;

Decreases in Mercury Wet Deposition over the United States during 2004–2010: Roles of Domestic and Global Background Emission Reductions

Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USA
Author to whom correspondence should be addressed.
Received: 8 April 2013 / Revised: 26 April 2013 / Accepted: 6 May 2013 / Published: 10 May 2013
(This article belongs to the Special Issue Atmospheric Mercury)
Full-Text   |   PDF [1857 KB, uploaded 10 May 2013]   |  


Wet deposition of mercury (Hg) across the United States is influenced by changes in atmospheric conditions, domestic emissions and global background emissions. We examine trends in Hg precipitation concentrations at 47 Mercury Deposition Network (MDN) sites during 2004–2010 by using the GEOS-Chem nested-grid Hg simulation. We run the model with constant anthropogenic emissions and subtract the model results from the observations. This helps to remove the variability in observed Hg concentrations caused by meteorological factors, including precipitation. We find significant decreasing trends in Hg concentrations in precipitation at MDN sites in the Northeast (−4.1 ± 0.49% yr−1) and Midwest (−2.7 ± 0.68% yr−1). Over the Southeast (−0.53 ± 0.59% yr−1), trends are weaker and not significant, while over the West, trends are highly variable. We conduct model simulations assuming a 45% decrease in Hg emissions from domestic sources in the modeled period and a uniform 12% decrease in background atmospheric Hg concentrations. The combination of domestic emission reductions and decreasing background concentrations explains the observed trends over the Northeast and Midwest, with domestic emission reductions accounting for 58–46% of the decreasing trends. Over the Southeast, we overestimate the observed decreasing trend, indicating potential issues with our assumption of uniformly decreasing background Hg concentrations. View Full-Text
Keywords: mercury; wet deposition; trend; GEOS-Chem; nested-grid model mercury; wet deposition; trend; GEOS-Chem; nested-grid model

Figure 1

This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).

Supplementary material


Share & Cite This Article

MDPI and ACS Style

Zhang, Y.; Jaeglé, L. Decreases in Mercury Wet Deposition over the United States during 2004–2010: Roles of Domestic and Global Background Emission Reductions. Atmosphere 2013, 4, 113-131.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Atmosphere EISSN 2073-4433 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top