On the effect of sea drops on the atmospheric boundary layer

One of the possible mechanisms responsible for the reduction of the sea surface drag at high winds is explored. The mechanism is based on the direct effect of sea drops (as heavy particles) on the turbulent mixing. If assumed that sea drops are ejected upward from the sea surface, no significant effect can be found. A more realistic picture presumes that the spume drops (resulting from a mechanical tearing of wave crests) are ejected “horizontally” at altitudes of breaking crests. A model of the spume drops generation is proposed. The spume drops, being torn off from breaking crests and sprayed inside the airflow, significantly affect the surface drag. At highest model wind speeds (60–80 m/s) the model actually predicts an effect of the “slippery surface” when the drag coefficient is reduced in about 10 times. A comparison with available observations is given.