| Title: | Coupled Ocean-Atmosphere-Vegetation Models of Warm Climates |
| Author: | Paul J Valdes |
| Date Submitted: | 04/29/2002 |
| Address: | Earley Gate,
Whiteknights
Reading
UK
RG6 6BB
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| Phone: | 44 118 931 6517 |
| Email: | P.J.Valdes@reading.ac.uk |
| Co-Authors: | Markwick, P. M, Robertsons Research International, UK, pjm@robresint.co.uk |
| Affiliation: | Department of Meteorology, University of Reading |
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| Abstract URL: | http://cis.whoi.edu/science/GG/ccod/viewAbstracts.cfm?RefNumber=19725510 |
| Author Homepage: | http://www.met.rdg.ac.uk/~swsvalde |
| Keywords: | Climate Model, Maastrictian, Vegetation, Ocean |
| Abstract: | Computer climate models provide a useful tool for examining the processes influencing Cretaceous climates, and a large scale (global) perspective to aid in the interpretation of the proxy climate indicators. In turn, the geological data represents an extreme test of the climate models. Previous work in computer modelling of warm climates such as the Cretaceous and Eocene has often been limited to simulating part of the total climate system. Most commonly, simulations have been performed with atmospheric models coupled to either prescribed sea surface temperatures or a simple ocean model. Alternatively, ocean models have used simple parameterisations of the atmosphere.
In this paper we will review past work and present new simulations using some of the very latest coupled ocean-atmosphere-vegetation models. Our main focus will be on the late Cretaceous (Maastrictian) but work on the mid-Cretaceous and early Eocene will also be mentioned. We are using a version of the Hadley Centre climate model. The coupled model is predicting very warm tropical ocean temperatures, and relatively warm benthic temperatures. Deep water formation is mainly at high latitudes, and is seasonally varying, with the deepest mixing occurring off the coast of Antarctica. Vegetation feedback can be important locally but has only little impact on the global mean. The reasons for the warmth will be discussed and the results will be compared to data. Winter temperatures in continental interiors continue to be the major problem for model-data comparisons. The extent of the disagreement will be considered. |
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