The Role of Boundary Conditions in the Middle Miocene Climate Evolution

摘要: Since the beginning of Cenozoic era (65 million year (MA) ago) climate has underwent a stepwise transition from former Greenhouse into an Ice House with altering warm and cold periods. One major step was Paleocene/Eocene (55 Ma years to Eocene/Oligocene boundary (34 first sheet formation in Antarctica. Another cooling took place during Miocene period (23 5 ago). For Middle (15 proxy data sea surface temperature suggest flatter than today equator-to-pole gradient, warmer high latitudes. We investigate using Community Earth System Model COSMOS-ASO. The conditions for GCM are plate tectonics reconstructions global topography while land cover vegetation kept as they today. Atmospheric CO2 concentration is set present day (360ppm) values recent studies range 150 up 500ppm. A control simulation performed comparing our modern climate. After several hundreds integration we can address some questions. How does evolve under conditions? Which processes most important different state? Can this be compared data?