THERMODYNAMIC STRUCTURE OF THE MONSOON BOUNDARY-LAYER UNDER THE INFLUENCE OF A LARGE-SCALE DEPRESSION

Using data from the MONsoon Trough Boundary Layer EXperiment (MONTBLEX ), the thermodynamic structure of the atmospheric boundary layer (ABL) under the influence of a monsoon depression has been studied. When th e depression was in the vicinity of the observing station, the soundin gs showed an increase in potential temperature, the sub-cloud layer wa s well mixed, the wind speed increased to 35 m/s, and the monsoon boun dary layer was convectively more unstable at night than in the daytime . Cloud-top processes, which lead to an apparent breakdown of the boun dary layer, seem to explain this.