21-28The acoustic sounder data obtained during the period June 1980-May 1981 have been analyzed with special reference to sea breeze. Simultaneous measurements of sea breeze using pilot balloon ascents and acoustic sounder were made on eight days in May 1981. A reasonably good agreement has been obtained between the acoustic sounder estimation of the depth of the sea breeze and the height of the onshore flow as deduced from hourly balloon ascents. The height variations of the elevated layer on the sounder record were also reflected in the flow patterns. The development of the elevated layer associated with the sea breeze circulation was delayed due to the limited vertical extent of sea breeze in the first few hours after the onset. The alternation or land and sea breeze more than once during a day in the observational period was partly due to the oscillatory behaviour of a trough of low pressure inland. The monthly charts prepared for the 12 months showed a definite seasonal variation in the diurnal behaviour of the coastal boundary layer at Visakhapatnam
