HR: 09:45h
AN: GC41B-08    [Abstracts]
TI: Solar-Cycle Warming at the Earth's Surface
AU: * Camp, C D
EM: camp@calpoly.edu
AF: California Polytechnic State University, Department of Mathematics, San Luis Obispo, CA 93407, United States
AU: Tung, K
EM: tung@amath.washington.edu
AF: University of Washington, Applied Mathematics Department Box 352420, Seattle, WA 98195, United States
AB: Using the NCEP/NCAR Reanalysis and the ERA-40 datasets, we analyze the global response of the Earth's surface temperature to oscillations in the total solar irradiance associated with the 11-year solar cycle. Three analysis methods are considered, with increasing levels of sophistication: global-mean averaging, composite- mean-difference projection and linear discriminant analysis (LDA). Within each dataset, the analysis results are consistent with each other (i.e., each within the other's error bars), with the method of LDA yielding the smallest error bar, and the unfiltered global-mean data yielding the largest error bar in the temperature amplitude. All three methods are able to demonstrate that there exists an 11-year oscillatory signal in the temperature data which is statistically significant and attributable (i.e., related) to the solar cycle. Using the LDA method, we deduce the spatial surface pattern over the globe which best distinguishes the solar maximum years from the solar minimum years. The resulting warming pattern shows a polar amplification of warming and a preferential warming over continents than over oceans. We propose that if positive feedback processes such as ice-albedo, water-vapor/lapse rate and cloud feedbacks (similar to some of those studied for the greenhouse warming problem) are incorporated, then the magnitude of the surface warming is consistent with direct solar radiative forcing.
DE: 1610 Atmosphere (0315, 0325)
DE: 1650 Solar variability (7537)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting