LATENT AND SENSIBLE HEAT COEFFICIENTS BASED ON DRAG COEFFICIENT AFFECTED BY WAVE AGE AND SEA SPRAY

Abstract

 Momentum exchange coefficient (resistance coefficient) which is an index of momentum exchange between the air-sea surface has been treated as monotonically increasing with the wind speed. However, wind speed profile is deferent from a logarithmic law of wind speed because under severe storm turbulent flow is suppressed by sea spray generated from the sea surface. Moreover, from observational studies, it was found that the momentum exchange coefficient has a peak at about 33 m/s. Wave conditions also vary when sea spray exists under a severe storm. Liu et al. (2012) proposed a momentum exchange coefficient taking account of the effects of sea spray and wave age. In this study, the heat exchange coefficient is derived based on the bulk transport equation useful in the numerical meteorological model from the same momentum exchange coefficient. The latent and sensible heat exchange coefficient have the peak when the wave age is 0.4 and the wind speed is 25 33 m/s. This new coefficient allows us to discuss the effects of sea spray and wave age effects.