From greenhouse to icehouse: the late Mesozoic-Cenozoic Arctic Ocean sea ice and climate history

Within this review paper, proxy records were used for reconstruc- tion of the late Mesozoic-Cenozoic long-term climate history of the Arctic Ocean with a focus on sea ice and sea-surface temperature. In this context, three examples representing different climatic stages of the Arctic Ocean on its way from Greenhouse to Icehouse conditions are presented and discussed: (1) the late Cretaceous, a time interval of pre-dominantly warm climate with strong seasonality and occasionally winter sea ice, some increased paleopro- ductivity, and probably oxygen-deficient conditions; (2) the mid-Eocene with continuing warm and euxinic conditions and partly increased paleoproduc- tivity, and the early onset of predominantly seasonal sea-ice conditions, and (3) the late Miocene characterized by relatively warm (SSTs of about 5 °C) and ice-free conditions during summer, as well as sea ice occurring during spring and autumn/winter