In this study, satellite observations are used as a basis for compositing in situ data from moorings to compensate for the lack of a spatially dense mooring array. The variability in the position of the SST front caused by westward propagating TIWs enables fixed mooring locations to measure the atmospheric boundary layer response from a large range of locations relative to the front. The satellite data enable determination of the precise location of the mooring relative to the front. The advantage of this strategy is the recurring measurement of the ABL response to the SST front over the thirteen month period considered here.
The results indicate that the TIW-induced perturbations of sensible heat flux are spatially shifted in phase towards the east relative to the perturbations of SST. The maximum fluxes of sensible heat are not centered directly over the warmest water, but are shifted towards the portion of the frontal region where a disequilibrium boundary layer is expected due to the advection of colder air from the equatorial region. The latent heat flux pattern is approximately in phase with the SST, with only a slight shift to the east. The changes of sensible and latent heat fluxes across the SST front have typical magnitudes of about 12 Wm-2 and 125 Wm-2, respectively.
The sensible and latent heat flux patterns are interpreted in two complementary ways: (1) as an atmospheric response to the change of oceanic forcing as air flows across the SST front; and (2) as the atmospheric response to westward propagating TIWs along the SST front.