Joint Seminar: The role of wind work for the ocean circulation - a lesson learned from a 5km coupled ICON simulation
Wind work has long been considered as one of the two major energy suppliers that provide the canonical value of total 2 TW needed to sustain the oceanic overturning circulation. Here, the role of the wind work is quantified by evaluating the wind-induced near-inertial wave energy flux that radiates from the mixed layer bottom into the ocean interior using a 5km coupled ICON simulation.
By examining the wind energy input at the surface under different weather conditions, ranging from tropical cyclones (hurricanes) to small-scale less-extreme weather disturbances, we find that the estimate of the surface wind input depends not only on the wind stress used - as suggested by previous studies - but also on the ocean model used. While the surface currents in a slab ocean model or a non-eddying ocean circulation model are strongly slaved to the wind stress forcing, the surface currents in the 5km coupled ICON model can be more strongly determined by internal instability process (eddies) than by the wind stress forcing arising from less-extreme weather disturbances.
Our result corrects the previous estimates of the global wind energy input to surface near-inertial motions down, from up to more than 1 TW to about 0.23 to 0.27 TW, depending on season. With this low wind input at the surface, the wind-induced near-inertial wave energy flux at the mixed layer bottom, that can be turned into mixing in the oceanic interior, is well below 0.1 TW.
Datum
02.11.2022
Uhrzeit
13:30–14:30 Uhr
Ort
- Bundesstr. 53, room 022/023
- Seminar Room 022/023, Ground Floor, Bundesstrasse 53, 20146 Hamburg, Hamburg
ReferentIn
Jin-Song von Storch, Max Planck Institute for Meteorology