Additional Participants

Other Collaborators

Clavin J. Heusser
Linda E. Heusser
Thomas V. Lowell
Bjorn G. Andersen
Christian Schlucter

Project Period

December 15, 1992-November 30, 1998

Level of Access

Open-Access Report

Grant Number

9219254

Submission Date

2-25-2004

Abstract

In the late 1980s, Broecker and Denton prepared papers on the concept that glacial-to-interglacial transitions involved global reorganizations of the ocean-atmosphere system (Broecker, W. S. and Denton, G. H., 1989. The role of ocean-atmosphere reorganizations in glacial cycles. Geochimica et Cosmochimica Acta, 53, 2465-2501; Broecker, W. S. and Denton, G. H., 1990, What drives glacial cycles? Sci. American, 262, 49-56). These reorganizations were thought to constitute jumps of Earth's climate systems between stable modes of operation, and they featured changes in the greenhouse-gas content or reflectivity of the atmosphere. In that concept, switches in thermohaline circulation, resulting from changes in ocean salinity, drive the abrupt mode flips. A key test of this notion of ocean-atmosphere reorganizations involved the timing and magnitude of climatic changes in the Southern Hemisphere. The fundamental question addressed in this research is whether climate changes in the Northern and Southern Hemispheres were synchronous and of similar magnitude during the last glacial/interglacial transition. The answer to this question requires detailed paleoclimatic records from key localities in the Southern Hemisphere. As outlined below, in the course of this research we retrieved such records from the Chilean Andes in middle latitudes of the Southern Hemisphere.

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