HR: 1340h
AN: A53B-0878    [Abstracts]
TI: Regional Climate Response to Three Different Representations of Preindustrial Land Cover in the Western United States
AU: * Bryant, S E
EM: sbryant@es.ucsc.edu
AF: Dept. of Earth Sciences, University of California, Santa Cruz, 1156 High St, Santa Cruz, CA 95064 United States
AU: Snyder, M A
EM: msnyder@es.ucsc.edu
AF: Dept. of Earth Sciences, University of California, Santa Cruz, 1156 High St, Santa Cruz, CA 95064 United States
AU: Sloan, L C
EM: lcsloan@es.ucsc.edu
AF: Dept. of Earth Sciences, University of California, Santa Cruz, 1156 High St, Santa Cruz, CA 95064 United States
AU: Diffenbaugh, N S
EM: diffenbaugh@purdue.edu
AF: Dept. of Earth and Atmospheric Sciences, Purdue University, 550 Stadium Mall Dr, West Lafayette, IN 47907 United States
AB: The impacts on climate from anthropogenic changes in land use and, therefore, land cover characteristics have not been examined to the same level as the impacts of increasing atmospheric greenhouse gases. Global-scale climate studies indicate that changes in land surface character have had relatively large impacts on climate, with the most substantial responses occurring at the regional scale. It is important to understand the role of land cover in regional models, as anthropogenic land cover change continues to influence regional climates. In this study, we tested the sensitivity of a regional climate model, RegCM2.5, to three representations of potential preindustrial vegetation in the Western United States. We used the global National Center for Atmospheric Research (NCAR) Community Climate Model (CCM3) to drive the regional model. We performed one 17-year RegCM integration over the Western United States with each of the three land cover datasets. Each integration used the same driving conditions with 280 ppmv atmospheric CO$_{2}$. We used (1) the potential natural land cover dataset of BIOME4, which is an equilibrium vegetation model (Kaplan, 2001); (2) the satellite-based preindustrial dataset developed by Ramankutty and Foley (1999), and; (3) as a control, the RegCM2.5 default vegetation dataset. Results from the three runs were compared to reveal any statistically significant differences in values for climate characteristics such as surface temperature, evapotranspiration, and precipitation. The results allow us to examine the sensitivity of regional climate to specified land cover.
DE: 3322 Land/atmosphere interactions
DE: 3337 Numerical modeling and data assimilation
DE: 1600 GLOBAL CHANGE (New category)
DE: 1620 Climate dynamics (3309)
DE: 0315 Biosphere/atmosphere interactions
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting