HR: 0800h
AN: C21C-1116    [Abstracts]
TI: Climate Change, Feedbacks, and the Arctic Hydrologic Cycle
AU: * Miller, J
EM: miller@marine.rutgers.edu
AF: Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901 United States
AU: Francis, J
EM: francis@marine.rutgers.edu
AF: Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901 United States
AU: Chen, Y
EM: ychen@giss.nasa.gov
AF: NASA/GISS, 2880 Broadway, New York, NY 10025 United States
AU: Chan, W
EM: weihan@eden.rutgers.edu
AF: Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901 United States
AU: Secora, J
EM: secora@imcs.rutgers.edu
AF: Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, NJ 08901 United States
AU: Russell, G
EM: gary.l.russell@nasa.gov
AF: NASA/GISS, 2880 Broadway, New York, NY 10025 United States
AB: Future climate change is likely to be enhanced in high northern latitudes. During the last 50 years, Arctic temperature, river discharge, and spring/summer cloud cover have been increasing, sea ice has been decreasing, and permafrost has been melting. We combine observations and global climate model simulations to examine some of the connections and feedbacks among these variables for the present climate and for a future climate in which atmospheric greenhouse gases are increasing. Although the well-known sea-ice albedo feedback mechanism appears to account for some of the projected temperature increase in the Arctic, increased water vapor and spring/summer cloud cover also play a role by increasing the flux of downward longwave radiation. A neural network approach is used to quantify relationships between these climate variables. The increased cloud cover and water vapor are related to changes in the hydrologic cycle. We examine the observed and modeled trends in atmospheric and terrestrial water fluxes into the Arctic. Siberian rivers show increasing trends in discharge during the last 50 years, and additional increases are projected through this century. In addition there appears to be a relationship between annual river flow and sea-ice extent anomalies. We also use the model to examine how melting permafrost is related to trends in Siberian river discharge. Results from the model simulations indicate that many of the present trends will continue throughout the century.
DE: 1836 Hydrological cycles and budgets (1218, 1655)
SC: Cryosphere [C]
MN: Fall Meeting 2005