HR: 0830h
AN: PP41C-0848    [PDF]
TI: Model Simulations of Orbitally Forced Terrestrial and Surface Ocean Variability in the Paleogene Greenhouse Climate
AU: * Bice, K L
EM: kbice@whoi.edu
AF: Woods Hole Oceanographic Institution, Mail Stop #23, Woods Hole, MA 02543 United States
AU: Norris, R D
EM: RNorris@ucsd.edu
AF: Scripps Institution of Oceanography, 308 Vaughan Hall, La Jolla, CA 92093 United States
AB: We have performed an extensive suite of slab ocean GCM experiments in order to begin to understand cyclical changes in carbonate content observed in Paleocene and Eocene sediments recovered from Demerara Rise (ODP Leg 207). In the first part of this study, the sensitivity of surface temperature and moisture flux fields will be compared against globally distributed Eocene terrestrial records in order to determine the degree to which the model's prediction of atmospheric changes compares with cycles in terrestrial paleoclimate records. In addition, model-predicted upper ocean forcing temperature and moisture flux changes will be compared against variations in planktonic foraminiferal oxygen isotope signals in high resolution Paleogene records from the subtropical North Atlantic. Atmospheric model experiments were performed with the GENESIS v. 2.0 model using an early Eocene paleogeographic reconstruction, 1500 ppm CO2 and solar luminosity reduced by 0.3 percent from the modern. We have seen that the use of general circulation models to reliably define the paleoclimate variations expected on orbital timescales requires model runs with at least 30 years of quasi-steady state output. A high degree of variance in the precipitation field in tropical latitudes and autocorrelation in surface temperature over ocean model cells requires datasets of at least 30 years of output in order to define statistically significant differences between experiments with different specified orbital configurations.
DE: 1620 Climate dynamics (3309)
DE: 3319 General circulation
DE: 3344 Paleoclimatology
DE: 9604 Cenozoic
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2003 Fall Meeting