HR: 0800h
AN: B41A-0162    [Abstracts]
TI: Isolating the Effect of Surface Roughness Changes on Climate
AU: * Kirk-Davidoff, D B
EM: dankd@atmos.umd.edu
AF: University of Maryland, College Park, Department of Atmospheric and Oceanic Science 3423 Computer and Space Sciences, College Park, MD 20742 United States
AU: Keith, D W
EM: keith@ucalgary.ca
AF: University of Calgary, Department of Chemical and Petroleum Engineering 2500 University Drive NW, Calgary, AB T2N 1N4 Canada
AB: Recent work (Keith et al, 2004) on the climate impact of very large scale wind farms has demonstrated appreciable effects on surface temperature, including warming and cooling on the order of a degree Celsius. In order to clarify the physical mechanisms of this impact, we have run simplified simulations of wind farm climate impacts, running the NCAR Community Atmosphere Model version 3.0 in "Aquaplanet" mode, with specified surface roughness and fixed sea surface temperatures. A circular region of enhanced surface roughness is imposed on the model. Several experiments, varying the location, size, and roughness of this region are performed. Results exhibit a Rossby wave response to the surface roughness perturbation. Southerly wind anomalies are correlated with increased tropospheric temperatures, resulting in increased downwelling infrared radiation at the surface. However, they are also correlated with increased cloudiness and albedo, and thus with reduced solar heating. These competing effects of warm advection on infrared and solar heating at the surface result in a complicated response pattern as the amplitude of the response decays away from the roughened region. This pattern in turn sheds light on the complicated climate impacts of wind farms found by Keith et al (2004).
DE: 1600 GLOBAL CHANGE
DE: 1626 Global climate models (3337, 4928)
DE: 1637 Regional climate change
DE: 3307 Boundary layer processes
DE: 3319 General circulation (1223)
SC: Biogeosciences [B]
MN: Fall Meeting 2005