Mercury Speciation at a Coastal Site in the Northern Gulf of Mexico: Results from the Grand Bay Intensive Studies in Summer 2010 and Spring 2011

Atmosphere

Xinrong Ren⁶  Winston T. Luke⁶  Paul Kelley⁶  Mark Cohen⁶  Fong Ngan⁶  Richard Artz⁶  Jake Walker³  Steve Brooks⁶  Christopher Moore¹  Phil Swartzendruber⁴  Dieter Bauer⁴  James Remeika⁴  Anthony Hynes⁴  Jack Dibb⁵  John Rolison²  Nishanth Krishnamurthy²  William M. Landing²  Arsineh Hecobian⁷  Jeffery Shook⁷ 

[1] Division of Atmospheric Sciences, Desert Research Institute, 2215 Raggio Parkway, NV 89512, USA; E-Mail:;Department of Earth, Ocean, and Atmospheric Science, Florida State University, 117 North Woodward Avenue, Tallahassee, FL 32306, USA; E-Mails:;Grand Bay National Estuarine Research Reserve, 6005 Bayou Heron Road, Moss Point, MS 39562, USA; E-Mail:;Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA; E-Mails:;Earth Systems Research Center, Institute for the Study of Earth, Oceans and Space, University of New Hampshire, 8 College Road, Durham, NH 03824, USA; E-Mail:;Air Resources Laboratory, National Oceanic and Atmospheric Administration, 5830 University Research Court, College Park, MD 20740, USA; E-Mails:;School of Earth and Atmospheric Science, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332, USA; E-Mails:

关键词: atmospheric mercury;    gaseous elemental mercury;    gaseous oxidized mercury;    particulate-bound mercury;    Gulf of Mexico;    principal component analysis;    HYSPLIT;   

DOI  :  10.3390/atmos5020230

来源: mdpi

【 摘 要 】

During two intensive studies in summer 2010 and spring 2011, measurements of mercury species including gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particulate-bound mercury (PBM), trace chemical species including O₃, SO₂, CO, NO, NO_Y, and black carbon, and meteorological parameters were made at an Atmospheric Mercury Network (AMNet) site at the Grand Bay National Estuarine Research Reserve (NERR) in Moss Point, Mississippi. Surface measurements indicate that the mean mercury concentrations were 1.42 ± 0.12 ng∙m⁻³ for GEM, 5.4 ± 10.2 pg∙m⁻³ for GOM, and 3.1 ± 1.9 pg∙m⁻³ for PBM during the summer 2010 intensive and 1.53 ± 0.11 ng∙m⁻³ for GEM, 5.3 ± 10.2 pg∙m⁻³ for GOM, and 5.7 ± 6.2 pg∙m⁻³ for PBM during the spring 2011 intensive. Elevated daytime GOM levels (>20 pg∙m⁻³) were observed on a few days in each study and were usually associated with either elevated O₃ (>50 ppbv), BrO, and solar radiation or elevated SO₂ (>a few ppbv) but lower O₃ (~20–40 ppbv). This behavior suggests two potential sources of GOM: photochemical oxidation of GEM and direct emissions of GOM from nearby local sources. Lack of correlation between GOM and Beryllium-7 (⁷Be) suggests little influence on surface GOM from downward mixing of GOM from the upper troposphere. These data were analyzed using the HYSPLIT back trajectory model and principal component analysis in order to develop source-receptor relationships for mercury species in this coastal environment. Trajectory frequency analysis shows that high GOM events were generally associated with high frequencies of the trajectories passing through the areas with high mercury emissions, while low GOM levels were largely associated the trajectories passing through relatively clean areas. Principal component analysis also reveals two main factors: direct emission and photochemical processes that were clustered with high GOM and PBM. This study indicates that the receptor site, which is located in a coastal environment of the Gulf of Mexico, experienced impacts from mercury sources that are both local and regional in nature.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.