Implications of the oceanic thermal skin temperature deviation at high wind speed

Extensive oceanographic and atmospheric observations obtained during three independent experiments in the Atlantic Ocean are used to demonstrate the relationship between wind speed and the temperature deviation Δ T , which is defined as the sea surface skin temperature (SSST) minus the subsurface bulk sea surface temperature (BSST). At wind speeds <6 m s −1 , the variability of Δ T increases because thermal stratification complicates the measurement and interpretation of Δ T : extreme Δ T magnitudes of >1.5 K are common during periods of high insolation. The variability of Δ T at night is reduced and extreme cool skin temperatures of < −0.5 K are recorded. In all cases, at wind speeds >6 m s −1 , the variability of Δ T is diminished and the mean value of Δ T approximates a cool bias of −0.14 K±0.1 K. We conclude that BSST measurements obtained at wind speeds >6 m s −1 , when corrected for a small ( −0.14 K) cool bias, are representative of the SSST and can be used with confidence to validate satellite derived SSST. When the wind speed is <6 m s −1 and the magnitude of Δ T is high, in situ radio metric SSST measurements are mandatory to validate satellite derived SSST.