Séminaire de Marion Kersalé - Atlantic Boundary Currents and Overturning Cells

Lundi 09 décembre à 13h Amphi Océanomed
Titre: Variability of the Atlantic Boundary Currents and Overturning Cells at 34.5°
Abstract: Variations in the Atlantic Meridional Overturning Circulation (AMOC) are thought to have important impacts on global scale climate phenomenon including precipitation patterns, surface air temperatures, coastal sea level, and extreme weather – and the AMOC structure in the South Atlantic is thought to control the stability of the entire AMOC system itself. Given this importance, significant resources have been invested on observing the AMOC in the South Atlantic over the past decade. In this presentation, multiple years of full-depth daily observations from moored instruments at 34.5°S are used to describe the eastern boundary currents at that latitude and the associated basin-wide AMOC. Velocity and water mass observations provide important insights into the local AMOC flow patterns, and in particular offer a new view of the upper and lower flows along the eastern boundary. Analysis of the AMOC using all available moored instruments from 2013 to 2017 allows us to observe for the first time the daily variability of both the upper and abyssal overturning cells. The variability of these flows is characterized in unprecedented detail, and their contribution to the AMOC is explored.