| Title: | Implications of an Atlantic gateway for the Cretaceous thermal maximum and atmospheric dynamics |
| Author: | Christopher Poulsen |
| Date Submitted: | 05/01/2002 |
| Address: | Department of Earth Sciences
Los Angeles
CA
USA
90089
|
| Phone: | 2137407952 |
| Email: | poulsen@usc.edu |
| Co-Authors: | Gendaszek, Andrew, Carleton College, gendasza@carleton.edu; Jacob, Robert, Argonne National Laboratory, jacob@mcs.anl.gov |
| Affiliation: | University of Southern California |
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| Abstract URL: | http://cis.whoi.edu/science/GG/ccod/viewAbstracts.cfm?RefNumber=19725596 |
| Keywords: | tropics, general circulation model |
| Abstract: | The Cretaceous thermal maximum was a major turning point in the history of Earth's climate. This interval of peak warmth in the Turonian has been attributed to very high atmospheric pCO2 resulting from rapid outgassing rates, though crustal cycling rates are thought to have peaked in the Aptian-Albian interval. On the basis of coupled ocean-atmosphere model simulations of the mid-Cretaceous, we hypothesize that the deepening of the Atlantic gateway could have contributed to the Cretaceous thermal maximum. Differences between pre- and post-rifting climate experiments demonstrate substantial regional oceanographic changes in the North and South Atlantic basins that are consistent with oxygen isotopic evidence used to infer a Cretaceous thermal maximum. The model results help reconcile the paleoclimate record foraminiferal  with our understanding of climate dynamics.
In addition, these Cretaceous simulations demonstrate that a redistribution of heat in the tropics can have substantial global climate consequences. With the initiation of an Atlantic gateway, global average surface temperature increases by approximately 0.4°C due to an invigorated hydrological cycle and enhanced greenhouse effect. In this talk, the atmospheric dynamical consequences of the rifting of Africa and South America will be highlighted. |
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