Changement climatique et Arctique et circulation océanique globale

Anthropogenic climate change is affecting major components of the Earth's climate system. Its impacts are particularly pronounced at high latitudes, where the rapid decline of Arctic sea ice is evident. Likewise, these impacts are also clear at low latitudes, as exemplified by the enhanced warming of the tropical Indian Ocean. Accordingly, the overarching goal of this project has been to investigate climatic links between a key element of global ocean circulation—the Atlantic Meridional Overturning Circulation (AMOC)—and changes in other ocean basins, including the Arctic, in the context of global warming. Over the years, this project has elucidated many critical topics relevant to anthropogenic climate change. These include the two-way interactions between the AMOC and Arctic sea ice. Specifically, AMOC weakening can delay the effects of Arctic amplification of global warming. Conversely, Arctic sea ice decline tends to contribute to AMOC weakening. Another problem addressed was the effect of changes in the tropical Indian Ocean on the northern high latitudes. In particular, we have shown that enhanced warming of the tropical Indian Ocean may have a stabilizing effect on the AMOC. Finally, we investigated the impacts of global warming on the tropical Pacific mean state and ENSO, including the mechanisms underlying extreme El Niño events. The project has been led by Drs. Alexey Fedorov, Eric Guilyardi, and Juliette Mignot of the Laboratory of Oceanography and Climate: Experiments and Digital Approaches (LOCEAN). It supported two PhD students and two postdoctoral researchers. Over its duration, the project led to the publication of approximately sixty manuscripts, including multiple papers published in Nature , Nature Climate Change , Nature Geoscience , and similar journals. Finally, the lead investigators conducted a broad range of outreach activities aimed at educating the public about the physics of climate change.