Abstract ATM-9509780 Berger, Wolfgang University of California, San Diego Title: California Current Sensitivity to Pacific Climate: Interdecadal Changes Reconstructed From Tree Rings and Varves Instrumental oceanic and atmospheric parameters along the American West Coast contain substantial decadal variability, but the record is too short to resolve temporal and spatial details at time scales greater than a few years. Observational studies of the climate "shift" in the North Pacific basin during the late 1970's suggest that decadal fluctuations may be linked to the Tropical Pacific perhaps via the frequency and intensity of El Nino versus La Nina events. An understanding of inter-decadal variability is crucial to evaluate global change phenomena. This award supports a project using proxy records for describing the decadal-to-century variability of the California Current at it relates to the Aleutian Low/West Coast Ridge complex and to warm and cool episodes in the Tropical Pacific. Since low-frequency temporal fluctuations usually have large spatial effects, this project will exploit an array of proxy climate records for the last millennium provided by tree-ring chronologies over the Western U.S. and by varve sediments in the Barbara Basin. This study will clarify whether recent decadal changes in the eastern North Pacific are a reflection of low-frequency natural variability or whether they represent a unique episode wit no analog. The proposed research is an interdisciplinary project involving the Geological Research Division and the Climate Research Division of Scripps Institution of Oceanography, together with the Laboratory of Tree-Ring Research of the University of Arizona.
