HR: 10:35h
AN: GC32A-02    [Abstracts]
TI: The Potential for Long-Term Impacts of Extreme Events in the Front Range of Colorado
AU: * Losleben, M V
EM: markl@culter.colorado.edu
AF: Institute of Arctic and Alpine Research, 1560 30th Street, Boulder, CO 80309 United States
AU: Caine, N
EM: cainen@Colorado.edu
AF: Institute of Arctic and Alpine Research, 1560 30th Street, Boulder, CO 80309 United States
AU: Flanagan, C
EM: colleen.flanagan@Colorado.edu
AF: Institute of Arctic and Alpine Research, 1560 30th Street, Boulder, CO 80309 United States
AU: McKnight, D
EM: Diane.Mcknight@colorado.edu
AF: Institute of Arctic and Alpine Research, 1560 30th Street, Boulder, CO 80309 United States
AU: Monson, R
EM: Russell.Monson@colorado.edu
AF: Dept of Ecology and Evolutionary Biology, Campus Box 334, Boulder, CO 80309 United States
AB: Extreme climatic events can trigger a cascade of events, or cause a step function change, in environmental systems that changes the balance of one or more environmental systems, such as bio-, geo-, hydro-, or chemical. They occur at all spatial, temporal, and intensity scales, some easily measurable, others more difficult. Moreover, not all extreme events have lasting environmental impacts. Whether they ƒ_oreset the environmental clockƒ__ or not is dependent on the particular system sensitivity in the geographic area of interest, as well as the type of event. Obviously, sufficient environmental data are necessary to detect and evaluate the potential of an extreme event to cause long-term change, and data scarcity is often a problem in the mountains of the western US. We look at the available data for five extreme events affecting the Front Range of the Colorado Rocky Mountains, and find a range of effects, suggesting that Front Range systems are more sensitive to drought than excessive moisture, and to events of longer duration. The events are defined by the surface climatic parameters of snow, rain, or temperature, and characterized by their synoptic atmospheric circulation pattern. Factors assessing the environmental impact include net ecosystem carbon dioxide exchange, alpine lake algal populations and hydrologic residence times, rock glacier temperatures, snowpack, and reservoir storage. The events are the April 15-16, 1921 record U.S. 24-hour snowfall at Silver Lake, CO, the 1981-86 upper elevation cold period in central Colorado and southern Wyoming, an anomalously high April and May 1995 snowfall, the 2002 drought, and the March 17-19, 2003 anomalously high snowfall in the South Platte and Arkansas River basins of Colorado.
DE: 0428 Carbon cycling (4806)
DE: 0736 Snow (1827, 1863)
DE: 3309 Climatology (1616, 1620, 3305, 4215, 8408)
DE: 3354 Precipitation (1854)
DE: 3364 Synoptic-scale meteorology
SC: Global Climate Change [GC]
MN: Fall Meeting 2005