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.




11:15 h


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


Liam Brannigan, Department of Physics, Oxford University


Carsten Eden

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