HR: 1330h
AN: U12A-0007
TI: The Importance of Precessional Signatures in the Tropical Climate
AU: * Clement, A C
EM: aclement@rsmas.miami.edu
AF: Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, 4600 Rickenbacker Cswy, Miami, FL 33149-1098
AU: Hall, A
EM: alexhall@atmos.ucla.edu
AF: University of California-Los Angeles, 7955 Math Sciences Building 405 Hilgard Ave. Dep't of Atmospheric Sciences Box 951565, Los Angeles, CA 90095
AU: Broccoli, A J
EM: ajb@gfdl.noaa.gov
AF: NOAA/Geophysical Fluid Dynamics Laboratory Princeton University, Forrestal CampusU.S. Route 1 P.O. Box 308, Princeton, NJ 08542
AU: Jackson, C
EM: charles@ig.utexas.edu
AF: University of Texas at Austin, 4412 Spicewood Springs Rd., Bldg. 600, Austin, TX 78759-8500
AB: The presence of orbital frequencies in the paleoclimate record is well established. The mechanisms that link the orbital forcing with climate, however, remain poorly understood. In this paper, we focus on climate change on orbital timescales in the tropics. Experiments with an atmospheric general circulation model are used to investigate the response of the tropical climate to precessional forcing. These results are compared with the tropical response to Last Glacial Maximum forcing. We find that while the glacial forcing has a large tropical mean signal in temperature, the precessional response of the hydrological cycle and atmospheric circulation are at least as large as that of the glacial, and at times of large eccentricity may overwhelm the glacial signal. These results emphasize the different nature of changes associated with the 100 kyr cycle of glaciation and the direct response to orbital forcing. Examples are given to show how these results can offer quantitative aid in deciphering these signals in tropical paleoclimate records.
DE: 1600 GLOBAL CHANGE
DE: 1620 Climate dynamics (3309)
DE: 4267 Paleoceanography
SC: U
MN: 2001 AGU Fall Meeting