Marine & Environmental Sciences Faculty Articles

Document Type


Publication Date


Publication Title

Journal of Physical Oceanography







First Page


Last Page



Heat and gas transport in molecular sublayers at the air-sea interface is governed by similar laws. A model of renewal type based on the physics of molecular sublayers allows the derivation of a parameterization of the temperature difference across the cool skin of the ocean and of the coefficient of the direct air-sea gas transfer. The surface Richardson number controls the transition from convective instability to wind-induced instability (“rollers” on breaking wavelets) and the Keulegan number controls the transition from the regime of rollers to long-wave breaking. A critical value of the surface Richardson number and of a nondimensional constant can be evaluated by comparing the parameterizations of the cool skin with field data. The critical value of the Keulegan number is determined from the wind speed at which long-wave breaking appears. The parameterizations have been compared with cool skin data obtained from campaigns in the tropical and subtropical Atlantic Ocean, while the gas transfer data are compiled from several experiments in the global ocean. The cool skin data have been used for an adjustment of the parameterization of the direct gas transfer. The parameterization does not include effects of bubble and droplet production in whitecaps, which can be important at high wind speed conditions.


©1994 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act September 2010 Page 2 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94-553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a web site or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS Copyright Policy, available on the AMS Web site located at ( or from the AMS at 617-227-2425 or





Peer Reviewed

Find in your library