A COMPARISON OF EOCENE CLIMATE MODEL RESULTS TO QUANTIFIED PALEOCLIMATIC INTERPRETATIONS

The integration of climate model results and geologic information offers considerable potential for deriving greater insight into the geologic record. In this study, climate model results and quantified climatic interpretations derived from proxy data are compared, to assess model capabilities and to examine proxy data interpretations. Atmospheric general circulation model experiments were used to produce a range of "possible" representative Eocene climate states, based on current knowledge of the Eocene record. The climate model experiments incorporate two idealized endmembers of Eocene ocean-surface temperature distributions characterized by very different latitudinal gradients. Model results are compared to quantified interpretations of the climate of early Eocene North America in an attempt to identify one of the sea-surface temperature distributions as more likely to have existed during the Eocene. The comparisons do not produce a conclusive match between inferred paleoclimatic information and any single case of model results, but some interesting insights become apparent. Model predictions of mean annual temperature and mean annual precipitation compare favorably to interpretations from geologic evidence, but there are large differences between model results and interpreted paleoclimatic parameters of minimum surface temperature and mean annual temperature range. Several possible causes for these differences are discussed.