1. Time mean MSLP bias (mbar) in CCSM its atmospheric component (CAM/AMIP).
CCSM4 MSLP bias is weaker than CCSM3 bias in the northern subtropical maxima. But …
MSLP bias increases in the South Atlantic
All pressure systems are above normal.

2. (left) Zonal wind bias (right) Tropical Atlantic SST bias
Ocean response is asymmetric: cold north warm south
Both trade winds are stronger than normal
Warm SST bias is in ocean only run forced by observed winds

3. Meridional currents (shading, red-northward) and water temperature (contours) 2o off the coast.
Eddy-permitting POP forced by the 20CR winds. Coastal jet of the Benguela current transports cold water along the Angola-Namibia coast
Both factors, resolution and wind forcing contribute to ocean model bias. In eddy resolving 0.1deg POP run of Multrud et al. (2010) the coastal jet of Benguela current is also weak. Next we will see that coastal wind stress from the Normal Year Forcing is weaker than QuikSCAT.
1deg CCSM4 ocean and 1deg POP forced by NYF. Missing cold water transport by the Benguela current. Possible reasons:
1deg ocean doesn’t resolve coastal dynamics
Coastal winds are not strong enough

4. Benguela coastal wind stress
Coastal wind stress from the Normal Year Forcing (NYF) is weaker than 20CR and QuikSCAT. Focus on the very coastal area (2 deg off the coast)
Both CCSM4 and CAM4/AMIP coastal wind stress are weaker than QuikSCAT. Winds further seaward are above normal reflecting elevated south subtropical pressure high.

5. Conclusions
MSLP centers are above normal and all global winds are too strong in CAM4/AMIP and CCSM4
Despite too strong trade winds, the tropical Atlantic has cold bias in the north and warm bias in the south.
Warm bias in the south originates (in part) in the ocean model component due to coarse resolution and weak coastal winds.