HR: 0800h
AN: A11C-0614    [Abstracts]
TI: Constraining Modern and Historic Mercury Emissions From Gold Mining
AU: * Strode, S A
EM: sstrode@atmos.washington.edu
AF: Dept. of Atmospheric Sciences, University of Washington, Box 351640, Seattle, WA 98195, United States
AU: Jaeglé, L
EM: jaegle@atmos.washington.edu
AF: Dept. of Atmospheric Sciences, University of Washington, Box 351640, Seattle, WA 98195, United States
AU: Selin, N E
EM: eckley@fas.harvard.edu
AF: Division of Engineering and Applied Sciences and Dept. of Earth and Planetary Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138, United States
AU: Sunderland, E
EM: Sunderland.Elsie@epamail.epa.gov
AF: EPA Office of Research and Development, Washington DC, 1 Congress Street Suite 1100, Boston, MA 02114, United States
AB: Mercury emissions from both historic gold and silver mining and modern small-scale gold mining are highly uncertain. Historic mercury emissions can affect the modern atmosphere through reemission from land and ocean, and quantifying mercury emissions from historic gold and silver mining can help constrain modern mining sources. While estimates of mercury emissions during historic gold rushes exceed modern anthropogenic mercury emissions in North America, sediment records in many regions do not show a strong gold rush signal. We use the GEOS-Chem chemical transport model to determine the spatial footprint of mercury emissions from mining and compare model runs from gold rush periods to sediment and ice core records of historic mercury deposition. Based on records of gold and silver production, we include mercury emissions from North and South American mining of 1900 Mg/year in 1880, compared to modern global anthropogenic emissions of 3400 Mg/year. Including this large mining source in GEOS-Chem leads to an overestimate of the modeled 1880 to preindustrial enhancement ratio compared to the sediment core record. We conduct sensitivity studies to constrain the level of mercury emissions from modern and historic mining that is consistent with the deposition records for different regions.
DE: 0322 Constituent sources and sinks
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
DE: 1610 Atmosphere (0315, 0325)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting