Steady State Ocean Response to Wind Forcing in Extratropical Frontal Regions

Steady State Ocean Response to Wind Forcing in Extratropical Frontal Regions

In regions of strong sea surface temperature (SST) gradients, the surface "geostrophic" currents have a vertical shear aligned with the surface density front defined by the temperature. This surface geostrophic ("thermal wind") shear can balance a portion of the surface wind stress, altering the classic Ekman response to wind forcing. Here we show that these frontal effects cannot be ignored in...

Southern Ocean Response to Relative Velocity Wind Stress Forcing

An eddy resolving quasi-geostrophic model of the Southern Ocean coupled to a dynamic atmospheric mixed layer is used to compare the performance of two different wind stress parameterisation schemes. The first is the standard quadratic drag law based on atmospheric velocity alone, while the second (more exact) formulation is based on the difference between ocean and atmosphere velocities. The tw...

The Response of the ITCZ to Extratropical Thermal Forcing: Idealized Slab-Ocean Experiments with a GCM

Using a comprehensive atmospheric GCM coupled to a slab mixed layer ocean, experiments are performed to study the mechanism by which displacements of the intertropical convergence zone (ITCZ) are forced from the extratropics. The northern extratropics are cooled and the southern extratropics are warmed by an imposed cross-equatorial flux beneath the mixed layer, forcing a southward shift in the...

Eddy Heat Flux in the Southern Ocean: Response to Variable Wind Forcing

The authors assess the role of time-dependent eddy variability in the Antarctic Circumpolar Current (ACC) in influencing warming of the Southern Ocean. For this, an eddy-resolving quasigeostrophic model of the wind-driven circulation is used, and the response of circumpolar transport, eddy kinetic energy, and eddy heat transport to changes in winds is quantified. On interannual time scales, the...

Extratropical forcing of ENSO