HR: 13:40h
AN: A43F-01 INVITED    [Abstracts]
TI: Snow and Ice Photochemistry in Polar Regions, and Interactions With a Changing Climate
AU: * Shepson, P B
EM: pshepson@purdue.edu
AF: Purdue University, Departments of Chemistry, West Lafayette, IN 47907, United States
AU: * Shepson, P B
EM: pshepson@purdue.edu
AF: Purdue Climate Change Research Center, 503 Northwestern Av., West Lafayette, IN 47907, United States
AU: * Shepson, P B
EM: pshepson@purdue.edu
AF: Purdue University, Department of Earth and Atmospheric Sciences, West Lafayette, IN 47907, United States
AB: Research in the Arctic over the past couple decades has revealed that a wide range of processes initiated at the frozen surface result in emission of photochemically reactive gases, e.g. HCHO, HONO, NOx, Br2, and BrCl to the overlying atmosphere. The resultant changes to the normally stable boundary layer can be quite dramatic, including the near complete depletion of ozone and elemental Hg in that layer, followed by deposition of the Hg oxidation products to the surface. For some species, these processes can impact both the composition of the lower atmosphere, and that of the snow/ice. Superimposed on the discovery of these processes is the knowledge that snowcover in coastal regions is changing, and sea ice areal extent (in September) is decreasing at as much as ~8%/decade. The snow/ice mediated chemical processes require a combination of physical and chemical conditions that are subject to change as a result of a changing climate. In this talk I will discuss the wide range of important processes mediated by snow and ice, some of the current ideas regarding how these processes may change over the coming decades, and what feedbacks and interactions there may be with climate change.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0365 Troposphere: composition and chemistry
DE: 0750 Sea ice (4540)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1863 Snow and ice (0736, 0738, 0776, 1827)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting