A STUDY OF WIND VELOCITY IN LOWER TROPOSPHERE USING THE INDIAN MST RADAR

The Indian MST radar located at Gadanki (13.47-degrees-N, 79.18-degree s-E) near Tirupati, Andhra Pradesh, was operated in the ST mode for fi ve days in February-March 1992 to obtain Doppler power spectra in the six beam positions, i.e. East, West, zenith-Y, North, South, and zenit h-X. The power spectra were used to determine the zonal, meridional an d vertical wind components in the lower troposphere (3.6 to 7.2 km). T he Fast Fourier Transform (FFT) analysis of time series for 24-26 Feb. and 23-24 Mar. 1992 shows that the waves of 5-10 and 16-20 min period icities dominate in the lower troposphere. The amplitude of the wave v elocity varies between 0.3 and 3.0 ms-1. The data were also used to st udy the wind shears, and significant shears were noted only above 6.0 km.