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 r elationship between wind speed and the temperature deviation Delta 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 varia bility of Delta T increases because thermal stratification complicates the measurement and interpretation of Delta T: extreme Delta T magnitudes of > 1.5 K are common during periods of high insolation. The variability of Delt a 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 Delt a T is diminished and the mean value of Delta T approximates a cool bias of -0.14 K +/- 0.1 K. We conclude that BSST measurements obtained at wind spe eds > 6 m s(-1), when corrected for a small (- 0.14 K) cool bias, are repre sentative 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 Delt a T is high, in situ radiometric SSST measurements are mandatory to validat e satellite derived SSST.