MID-CRETACEOUS OCEAN CIRCULATION: RESULTS FROM MODEL SENSITIVITY STUDIES

A series of ocean general circulation model (GCM) experiments for mid-Cretaceous continental paleogeography with atmospheric forcing prescribed from atmospheric GCM experiments are utilized to investigate the nature of the mid-Cretaceous ocean circulation. The experiments illustrate a Tethys system of clockwise currents and predominant eastward flow, in marked contrast with earlier reconstructions. This result is apparently robust for changes in bathymetry and in the degree of planetary warmth. Changes in sea level have the largest potential to produce alternative circulation characteristics. Two major current systems outside of Tethys dominate the model simulation. The site of bottom water formation is the North Pacific, however, in a sensitivity experiment for a warmer climate, the eastern Tethys a site of deep water formation.