LOW FREQUENCY OSCILLATIONS IN TROPOSPHERIC WINDS DURING CONTRASTING SUMMER MONSOON OVER INDIA

TIle'low frequency Iluctu atio ns in the troposphe ric wind field over India has been studied by spec tnuu~ na l l"i, tech nique. duri ng con trasting mon soons. namely, d rought and good monsoons ba sed on rainfall3cti\il)·. Si~ lliflc ant spectral peaks d urin g these years ha ve bee n iden tified.Zon al wind shea r in the lower tropospher ehan' also bern examin ed and the periodici ty in th e near 4()..day mode have bee n documented . Th e interannual, 'n.riill1i1ily of the mode and its potential as medium range predicti on tool has been examined in therrnpn perspect ive.