Vanishing potential temperature gradients in strong convection

Abstract

Abstract Temperature profiles recorded up to 30 m show an unexpected feature in conditions of free convection with light wind. Above the strong lapse near the ground, there is a transition to zero potential temperature gradient. The height of the transition level falls as the wind strength decreases, becoming less than 8 m when the negative Richardson number at 1·5 m is greater than 0·4. From reported observations over the sea it seems that the feature is present there also.