VHF radar studies of the migrating and nonmigrating diurnal and semidiurnal tides over a tropical and an equatorial station

摘要

VHF radar measurements of winds are utilized to study the diurnal and semi-diurnal tides over Gadanki and Kotatabang. The tidal amplitudes exhibit maxima in UTLS region during June-September over Gadanki and during March and September over Kotatabang. The vertical wavelength is 3–5 km (Gadanki) and 25–30 km (Kotatabang), which reveal the existence of nonmigrating and migrating tides, respectively. Brightness temperature shows that over Gadanki(deep) and Kotatabang(shallow) convective clouds. Release of latent heat due to deep-clouds is found to be the main source mechanism for nonmigrating tides. The present study brings out the differences in tides over equatorial and low latitude.