HR: 0800h
AN: A21C-0880    [Abstracts]
TI: LEADX-2005: A system study of near-surface winter tropospheric processes near Barrow, Alaska
AU: * Sturm, M
EM: msturm@crrel.usace.army.mil
AF: U.S. Army Cold Regions Research and Engineering Laboratory-Alaska, P.O. Box 35170, Ft. Wainwright, AK 99703-0170 United States
AU: Shepson, P B
A21C-0880 AF: Purdue University-Dept. of Earth and Atmospheric Sciences, 1393 Brown Building, West Lafayette, IN 47907-1393 United States
AU: Bottenheim, J W
A21C-0880 AF: Environment Canada-Air Quality Research Branch, 4905 Dufferin Street, Toronto, M3H 5T4 Canada
AU: Pinto, J
A21C-0880 AF: National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 United States
AU: Blum, J
A21C-0880 AF: University of Michigan-Geologic Sciences, 1100 North University Avenue, Ann Arbor, MI 48109-1005 United States
AU: Simpson, W R
A21C-0880 AF: University of Alaska-Geophysical Institute, 903 Koyukuk Drive, Fairbanks, AK 99775 United States
AU: Perovich, D K
A21C-0880 AF: U.S. Army Cold Regions Research and Engineering Laboratory-Alaska, P.O. Box 35170, Ft. Wainwright, AK 99703-0170 United States
AU: Douglas, T
A21C-0880 AF: U.S. Army Cold Regions Research and Engineering Laboratory-Alaska, P.O. Box 35170, Ft. Wainwright, AK 99703-0170 United States
AU: Brooks, S
A21C-0880 AF: NOAA Atmospheric Turbulence and Diffusion Division, 456 S. Illinois Ave., Oak Ridge, TN 37830 United States
AU: Rhew, R
A21C-0880 AF: University of California-Berkeley-Dept. of Geography, McCone Hall, Berkeley, CA 94720-4740 United States
AU: Keeler, G
A21C-0880 AF: University of Michigan-Geologic Sciences, 1100 North University Avenue, Ann Arbor, MI 48109-1005 United States
AB: In the Arctic, a set of vigorous and linked near-surface tropospheric processes commence in March with polar sunrise and continue until the snow melts in late May. In ways not fully understood, these processes produce ozone (ODE) and mercury (MDE) depletion events, the latter responsible for the introduction of mercury into the coastal marine and terrestrial arctic environments. The processes require a sea ice cover, open leads, diamond dust events, snowfall, and the presence of a snowpack on both land and sea. In March, 2005 we conducted a campaign (LEADX-2005) to investigate this suite of processes in the coastal strip near Barrow, Alaska. During a 17-day period when the coastal flaw lead was active and open, 30 scientists from more than 10 institutions made a set of coordinated measurements on, near, and inland from the lead. Measurements included continuous observations of surface weather, reactive halogens using MAX-DOAS, and near-surface mercury concentrations. Spot measurements of ozone and VOCs were made at the lead in a variety of ice and weather conditions. Airborne measurements were made using unmanned aerial vehicles (UAVs), tethered balloons, and kites. Deposited and newly fallen snow was sampled for ions, halogens, and mercury content on a daily basis on transects running from the lead inland several kilometers. Results suggest ozone depletion and mercury deposition occur at the regional (order 100 km) rather than local scale, but are confined to a thin layer of marine air (order 100 m). The processes evolve with time, the seasonal rise in air temperature, and the evolution of the snow pack, but considerable uncertainty remains as to the ultimate fate of the constituents (chiefly Hg) upon the completion of snow melt in the environment due to re-emission processes. From LEADX-2005 and follow-on studies we hope to develop a more systematic understanding of how these linked processes work across time and space.
DE: 0312 Air/sea constituent fluxes (3339, 4504)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
DE: 0736 Snow (1827, 1863)
DE: 0750 Sea ice (4540)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005