Past Ocean Dynamics
In order to assess the role of the ocean circulation in the global climate system our research group has turned towards the recent geological past. The last glacial/interglacial cycle (i.e., approximately the last 130,000 years) comprises a wide array of different boundary conditions under which ocean circulation changed profoundly. Hence, it provides an ideal natural laboratory for identifying the triggers and feedback mechanisms responsible for short-term climate change.
A prominent example of abrupt climate change during the last glacial/interglacial cycle is the recurring occurrence of so-called "Heinrich events”, when armadas of icebergs purged into the Atlantic Ocean, altering deep ocean circulation. Stalling of the Atlantic Meridional Ocean Circulation (AMOC) curtailed the northward advection of heat, inducing a sustained cold spell over much of the Northern Hemisphere. Strikingly, the succession of events that have caused these abrupt ocean circulation and climate changes has yet remained unclear. Although observational evidence for qualitative changes in past ocean circulation patterns has been established over the past few years, our knowledge about quantitative changes in circulation strength is arguably still fragmentary. Consequently, given the yet limited understanding of the processes involved in these changes, we cannot predict whether (and if yes, when) similar rapid transitions may occur again in the near future.
In light of the above, our Emmy Noether research group aims to quantitatively reconstruct past ocean dynamics based on the analysis of radioisotopes from deep-sea sediments (generated by the natural radioactive decay of uranium and samarium) that then are integrated with the output of semi-complex modeling studies.
Group leader: Dr. Jörg Lippold
phone: +49 (0)6221-54-5983
room: 503 / INF 234
Institute of Earth Sciences
Im Neuenheimer Feld 234