Spectral Characteristics of Surface Layer Turbulence Over the Tropical Ocean

Abstract

Spectra of wind, temperature and humidity fluctuations measured during BOMEX in the atmospheric surface layer are discussed. Strong similarities exist between dimensionless humidity and horizontal wind velocity spectra and between dimensionless cospectra of the water vapor flux and the momentum flux. In contrast, the peaks of the temperature spectra and the sensible heat flux cospectra occur at frequencies an order of magnitude greater than those of the other two variables. These differences are related to the mean vertical planetary boundary layer profiles of the three variables as well as to the effects of heating-cooling by divergence of radiation in the PBL.