Wind speed forcing of the bulk-skin sea surface temperature difference

Recent studies (Wick, 1995; Donlon and Robinson, 1996) have shown that at high wind speeds the difference between bulk and skin sea surface temperature (ΔT) is constant at -0.1 K and there is no further dependence of ΔT on wind speed. To test this relationship for different seasons and a larger geographic region the present authors examine moored buoy measurements in the Pacific of wind speed and bulk SST along with coincident estimates of the skin SST from infrared satellite measurements. In all seasons and for all locations nighttime ΔT is seen to be negatively correlated with wind speed up to 5 m/s. Above this wind speed the ΔT values cluster about a zero vertical line. During the day ΔTs for wind speeds below 5 m/s are less well correlated and the sign is positive; ΔT at wind speeds greater than 5 m/s shift from being generally positive values to generally negative values. Daytime ΔT values at higher wind speeds cluster about the vertical and lie mostly on the negative side of the zero line. Both day and night have similar RMS scatter (~0.35 K) for these vertical lines which is less than the RMS errors for both the strong nighttime correlations and the weaker daytime correlations