Recent circulation changes in the Northwest Atlantic

The Atlantic meridional overturning circulation (AMOC) is essential for our climate, redistributing heat from low to high northerly latitudes. Proxy data from the Northwest Atlantic margin suggest that it may have weekend over the last 150 years.

Here we explore different radiogenic isotope systems (Nd and Pb) to substantiate, or challenge recent AMOC weaking. We combine grain size specific analyses of authigenic and silicate sediment fractions to elucidate local and distal controls on authigenic signatures and to potentially confirm changes in near-bottom current flow in the Deep Western Boundary Current (DWBC).

Circulation and studied sites in the Northwest Atlantic

Lake-3 — Sediment authigenic and silicate Nd isotope compositions. Blue brackets indicate advected water mass signatures at ~2000 and ~3000 meters depth.

Team members

Student projects

Bamberg C. (2022). Coupled inorganic and organic isotope tracers in sediments of the Deep Western Boundary Current. Semester project.
Tallon M. (2021). Study of multiproxy signals of Northwest Atlantic margin sediments under the influence of the Deep Western Boundary Current. Research internship, ETH Zurich – ENS Lyon.