Speaker: Jörn Callies (MIT)
The ocean plays a key role in the industrial-era climate system: it has taken up nearly a third of the anthropogenic carbon and over 90% of the energy trapped by elevated greenhouse gas concentrations. The ocean circulation sequesters heat and carbon to depth and thereby regulates the exchange with the atmosphere at the sea surface. It has recently been recognized that energetic submesoscale fronts (1–10 km wide) may make a leading-order contribution to the exchange between the surface and interior ocean, a contribution that is not represented in current climate models. In this seminar, I will discuss the dynamics of submesoscale turbulence using a combination of observations, theory, and idealized numerical modeling. In contrast to the prevalent paradigm, it is found that baroclinic mixed layer instabilities are the key driver of energetic submesoscale turbulence, with implications for the surface–interior exchange.