HR: 0800h
AN: C31A-0284    [Abstracts]
TI: Eddy Covariance(EC) Over Snow in a Mountainous Environment to Determine Sensible and Latent Heat and Mass Fluxes.
AU: * Reba, M L
EM: mreba@nwrc.ars.usda.gov
AF: University of Idaho, Civil Engineering, 800 Park Blvd, Suite 105, Boise, ID 83712 United States
AU: Marks, D
EM: danny@nwrc.ars.usda.gov
AF: USDA-ARS Northwest Watershed Research Center, 800 Park Blvd, Suite 105, Boise, ID 83712 United States
AU: Link, T
EM: tlink@uidaho.edu
AF: University of Idaho, Department of Forest Resources PO Box 441133, Moscow, ID 83712 United States
AU: Link, A
EM: awinstra@nwrc.ars.usda.gov
AF: USDA-ARS Northwest Watershed Research Center, 800 Park Blvd, Suite 105, Boise, ID 83712 United States
AB: Sensible and latent heat and mass fluxes can represent a significant component of the snowcover energy and mass balance in mountain environments. Though these fluxes are computed in energy balance snow models, few measurements exist for comparison or validation. This research investigates the methodology required and problems associated with the direct measurement of sensible and latent heat flux over snow. The sensible and latent heat and mass fluxes can be determined directly from the turbulent fluctuations measured by fast-response sensors using eddy covariance (EC) theory. The general site considerations and specific weather conditions common to mountain catchments that affect EC data collection over snow is explored. Corrections and post-processing of eddy covariance data is discussed. Examples from established EC measurement sites under adverse and optimal conditions will be presented. The two primary EC study sites are located in southwestern Idaho in a small headwater catchment of the Reynolds Creek Experimental Watershed, located approximately 80 km southwest of Boise, Idaho. A protected, below canopy site is located within a stand of aspen trees, and an exposed site is located on a ridge over big mountain sagebrush. The study investigates the conditions under which EC instrument systems can be used in mountainous, snow-dominated environments, the processing required to prepare the data for analysis, and several examples of post-processed data collected over snow. This research will improve our understanding of how heat and mass flux from the snowcover may impact water resources under the variable and changing climate conditions so common in the Western US.
DE: 3307 Boundary layer processes
DE: 1833 Hydroclimatology
DE: 1863 Snow and ice (1827)
DE: 1878 Water/energy interactions
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting