The TRR 181 seminar is held by Fraser Goldsworth (University of Oxford) on June 30, 11 am.

Symmetric instability in cross-equatorial western boundary currents

Abstract

Over the last few decades our understanding of the Atlantic Meridional Overturning Circulation (AMOC) has progressed, with us no longer seeing it as a coherent "global conveyor", but as having contributions from many different current systems, which vary across a variety of temporal and spatial scales. In particular, the role of mesoscale variability has become better understood. In this talk I will examine the role of sub-mesoscale instability in idealised models of two western boundary currents which are known to be important AMOC pathways – in particular, the North Brazil Current and the Deep Western Boundary Current as it crosses the equator. I will explain how symmetric instability is generated in these currents, and compare and contrast the evolution of the instability in each of them.