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Geofysisk institutt

GFI/BCCR Seminar | Eystein Jansen: Abrupt climate change of the last ice age – are they relevant for the future?

Abrupt climate change of the last ice age – are they relevant for the future?

Eystein Jansen (GEO-UiB/BCCR, Norce Climate)

Abstract
Through the ice2ice project we investigate the architecture of past abrupt climate change as exemplified by Dansgaard Oescher events with emphasis on how the changes develop and are recorded in marine and ice core records. Detailed records of ocean, sea ice and atmospheric change are constructed and linked with unprecedented chronological accuracy. This enables us to clarify the role of the mechanisms involved, and to identify the sequence and phasing of changes that evolved through the abrupt events. The pivotal role of abrupt sea ice change in determining the abruptness of the events is underscored in the results. In parallell with the emprical evidence, a concerted modeling effort is undertaken, defining the sensitivity of the high-latitude ocean to change rapidly and to become unstable, and to test the impact of the abrupt changes to the mass balance of the Greenland ice sheet. I will compare the status in the period 40-30.000 years ago to the present and future Arctic, investigating the risks of future abrupt changes in the Arctic sea ice cover and its linkages with Greenland ice sheet.