Abstracts: Paleoenvironmental Analysis Based on Climate Model Predictions

BARRON, ERIC J

The considerable influence of climate on Earth processes and the variability of climate on geologic time scales is the impetus for paleoenvironmental research. Over the last two decades, models based on the physical laws that govern the atmosphere-ocean-ice system have been developed that can be applied to geologic problems. These models offer substantial opportunities for investigating past environments and enhancing the value of sedimentologic and paleontologic data. With increasing confidence gained through model-data comparisons, models can be applied to frontier areas.

Paleoenvironmental analysis based on climate model predictions must be based on several steps: (1) the aspects of the geologic record, which are the subject of analysis, must be closely tied to physical variables; (2) the physical variables of interest must be successfully predicted using the climate model; (3) the physical variables of interest must be sensitive to geologic forcing factors (e.g., changes in continental position, sea level, carbon dioxide, etc.), otherwise the application of a sophisticated climate model may be unnecessary; (4) sufficient data are required from the geologic record to test and evaluate the model predictions; and (5) the model-data comparison is required to assess the veracity of the model predictions.

These steps are applied to determine climate model capability to predict severe storms, including both hurricanes and winter storms, and to assess their impact on the sedimentary record. Climate models demonstrate substantial capability to predict winter storms, and hurricanes can be inferred from a set of hurricane genesis parameters predicted by the models. The intensity and distribution of severe storms show substantial sensitivity to geologic forcing factors (carbon dioxide, geography, topography, ocean heat transport, and solar luminosity are evaluated). Based on this analysis, severe storms are predicted at several time slices from the Permian glaciation to the warmth of the middle Cretaceous. The results compare successfully with the record of storm deposition for these time periods.

AAPG Search and Discovery Article #90938©1997-1998 AAPG Distinguished Lecturers