HR: 1340h
AN: A53B-1145    [Abstracts]
TI: Ozone Fluxes over Snow-Covered Environments
AU: * Helmig, D
EM: Detlev.Helmig@colorado.edu
AF: Institute of Arctic and Alpine Research (INSTAAR), University of Colorado, 1560 30th Street, Boulder, CO 80305, United States
AU: Bocquet, F
EM: Florence.Bocquet@colorado.edu
AF: Institute of Arctic and Alpine Research (INSTAAR), University of Colorado, 1560 30th Street, Boulder, CO 80305, United States
AU: Cohen, L
EM: Cohen.Lana@gmail.com
AF: Institute of Arctic and Alpine Research (INSTAAR), University of Colorado, 1560 30th Street, Boulder, CO 80305, United States
AU: Ganzeveld, L
EM: Laurens.Ganzeveld@wur.nl
AF: Department of Environmental Sciences, Wageningen University and Research Center, Wageningen, 6708, Netherlands
AU: Honrath, R E
EM: reh@mtu.edu
AF: Michigan Technological University, Dept. of Civil & Environmental Engineering 1400 Townsend Drive, Houghton, MI 49931, United States
AU: Neff, W
EM: William.Neff@noaa.gov
AF: National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States
AU: Oltmans, S J
EM: Samuel.J.Oltmans@noaa.gov
AF: National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States
AU: Seok, B
EM: Brian.Seok@colorado.edu
AF: Institute of Arctic and Alpine Research (INSTAAR), University of Colorado, 1560 30th Street, Boulder, CO 80305, United States
AU: Williams, M W
EM: Markw@Snobear.colorado.edu
AF: Institute of Arctic and Alpine Research (INSTAAR), University of Colorado, 1560 30th Street, Boulder, CO 80305, United States
AB: Until very recently ozone uptake to snow-covered environments was believed to be low and of secondary importance for surface-level ozone concentrations. Our recent studies from polar and midlatitude sites have resulted in contrary new insights into the interchanges of ozone with snow and shown the following: 1. Due to weak atmospheric ozone production and losses, ozone surface fluxes over snow, in particular in the polar regions, often have a determining influence on surface ozone levels. 2. Ozone fluxes in polar regions have significant diurnal and seasonal dependencies, with solar irradiance being a major driver of the ozone fluxes. 3. The ozone exchange is closely linked to photochemical production and exchange of nitrogen oxides, and under certain conditions increased levels of nitrogen oxides can result in photochemical ozone production and upwards ozone fluxes from the snow surface. 4. Gas exchange through the snow varies significantly depending on the gas permeability of the snowpack. 5. The substrate underneath the snow (e.g. glacial ice, sea ice, frozen (permafrost) soil, '‘warm'' midlatitude soil) influences the process-level controls, magnitude and direction of ozone fluxes. These new findings call for the need to develop more detailed parameterizations of ozone exchanges over snow for use in atmospheric chemistry and transport models.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
DE: 0736 Snow (1827, 1863)
DE: 0798 Modeling
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting