CLIMATE RESPONSE TO VARIATIONS OF THE GULF STREAM INTENSITY IN THE LATE MIOCENE – RESULTS OF AN EARTH SYSTEM MODEL OF INTERMEDIATE COMPLEXITY

The meridional overturning circulation in the Atlantic Ocean and, therefore, the northward ocean heat transport intensified in the Neogene, inter alia because of an open Central American Seaway. However, the effect of a weaker-than-present ocean circulation on climate on either side of the North Atlantic is still an open issue, especially with regard to the Neogene climate cooling. We present results of climate modelling sensitivity experiments, which focus on the climate response to different heat transports in the North Atlantic Ocean using an earth system model of intermediate complexity (EMIC). The sensitivity experiments represent conditions of Late Miocene (Tortonian, 11-8 Ma) and present-day, respectively. As a complement, a comparison with paleoclimate derived from paleobotanical records is undertaken within the project. [grant: DFG MI 926 / 8-1]