ESTIMATION OF SURFACE HEAT-FLUX AND INVERSION HEIGHT WITH A DOPPLER ACOUSTIC SOUNDER

In this paper, acoustic sounder (sodar) derived vertical velocity vari ance (sigma(w)(2)) and inversion height (Z(i)) are used to compute the surface heat flux during the convective activity in the morning hours . The surface heat flux computed by these methods is found to be of th e same order of magnitude as that obtained from tower measurements. In version heights derived from sodar reflectivity profiles averaged for an hour are compared with those obtained from the sigma(w)(3)/Z profil e. Variation of sigma(w)(2) in the mixed layer is discussed. The data were collected during the Monsoon Trough Boundary Layer Experiment 199 0 at Kharagpur. The analysis is made for four days which represent the pre-monsoon, onset, active and relatively weak phases of the summer m onsoon 1990. The interaction of the ABL with the monsoon activity is s tudied in terms of the variation of inversion height, vertical velocit y variance and surface heat flux as monsoon progresses from June to Au gust.