Joint Seminar: Intense PV mixing and nutrient upwelling in oceanic anti-cyclones caused by submesoscale instabilities

Numerous observations show the presence of anomalously high biological activity in anti-cyclonic eddies in the ocean.  This high productivity suggests that upwelling of nutrient-rich water from the thermocline occurs inside anti-cyclonic eddies.   However, this upwelling is not captured by existing climate models and so hinders efforts to close the carbon budget.  The upwelling process is considered here from a potential vorticity viewpoint.  High resolution numerical simulations show intense upwelling of high PV filaments from the thermocline in anti-cyclonic eddies and that the most likely cause of this upwelling is symmetric instability.  It is shown that anti-cyclonic eddies are highly unstable to symmetric instability and that this induces mixing of potential vorticity along stratification surfaces with cyclogenesis effects analogous to those in the troposphere.

Datum

21.05.2015

Uhrzeit

11:15 Uhr

Ort

Bundesstr. 53, room 022/023
Seminar Room 022/023, Ground Floor, Bundesstrasse 53, 20146 Hamburg, Hamburg

ReferentIn

Liam Brannigan, Department of Physics, Oxford University

Chair

Carsten Eden

Zur Übersicht