Atlantic Ocean Circulation over the Past Two Millennia and its Impact on European Climate

• Applicant: Professor Dr. Stefan Rahmstorf
• Subject Area: Oceanography
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 550037087

The Atlantic Meridional Overturning Circulation (AMOC) has a major impact on European climate, as it transports a large amount of heat northward along the Atlantic which is released to the atmosphere to the west and northwest of Europe. Climate variations such as the Roman Warm Period, the Medieval Climate Anomaly (also referred to as the Medieval Warm Period) and the colder periods of the Dark Ages and the Little Ice Age were mostly recorded around the North Atlantic, and it has been suggested that changes in the AMOC may have played a key role in these events. Nevertheless, so far no clear picture has emerged about variability of the Atlantic ocean circulation during the last two millennia, even though this is the best-documented era for decadal to centennial climate changes in Earth history. We therefore propose to investigate AMOC and other ocean circulation variability within the context of climatic changes over the past two millennia, combining information from proxy data (e.g. from ice cores and ocean sediments) and climate models using data assimilation techniques. Research questions include: • Did a weak AMOC contribute to the relative cold of the ‘Little Ice Age’ in Europe, or did conversely the cold conditions in the regions drive a strong AMOC by enhancing surface ocean density? • Has the subpolar gyre undergone an abrupt transition in the past 2000 years? • How are the AMOC changes in the open Atlantic linked to the flow into the Nordic Seas? • And how have past ocean circulation change and variability affected climate conditions in Europe? • What can we learn from these past climate changes for the future?

• DFG Programme: Research Grants
• International Connection: Belgium
• Partner Organisation: Fonds National de la Recherche Scientifique - FNRS
• Cooperation Partner: Professor Dr. Hugues Goosse