Oxidation of mercury by bromine in the subtropical Pacific free troposphere
Autor: | Lyatt Jaeglé, Nicola J. Blake, Shaojie Song, Frank Flocke, Lynne E. Gratz, J. L. Ambrose, Xianliang Zhou, Viral Shah, Rebecca S. Hornbrook, Geoffrey S. Tyndall, D. J. Knapp, Catalina Tsai, Andrew J. Weinheimer, Samuel R. Hall, Meghan Stell, Denise D. Montzka, Eric C. Apel, Daniel M. Stechman, Mike Reeves, Noelle E. Selin, Daniel A. Jaffe, Max Spolaor, James Festa, Jochen Stutz, Teresa Campos |
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Rok vydání: | 2015 |
Předmět: |
Bromine
010504 meteorology & atmospheric sciences chemistry.chemical_element North Pacific High 010501 environmental sciences Atmospheric sciences 01 natural sciences Nitrogen Mercury (element) Tropospheric ozone depletion events Trace gas Aerosol Troposphere Geophysics chemistry 13. Climate action General Earth and Planetary Sciences Environmental science 0105 earth and related environmental sciences |
Zdroj: | Geophysical Research Letters. 42 |
ISSN: | 1944-8007 0094-8276 |
Popis: | Mercury is a global toxin that can be introduced to ecosystems through atmospheric deposition. Mercury oxidation is thought to occur in the free troposphere by bromine radicals, but direct observational evidence for this process is currently unavailable. During the 2013 Nitrogen, Oxidants, Mercury and Aerosol Distributions, Sources and Sinks campaign, we measured enhanced oxidized mercury and bromine monoxide in a free tropospheric air mass over Texas. We use trace gas measurements, air mass back trajectories, and a chemical box model to confirm the origin and chemical history of the sampled air mass. We find the presence of elevated oxidized mercury to be consistent with oxidation of elemental mercury by bromine atoms in this subsiding upper tropospheric air mass within the subtropical Pacific High, where dry atmospheric conditions are conducive to oxidized mercury accumulation. Our results support the role of bromine as the dominant oxidant of mercury in the upper troposphere. |
Databáze: | OpenAIRE |
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