Intraseasonal oscillations over tropical Indian ocean in relation to monsoon onset and rainfall events over the peninsular India

Detailed analysis of the satellite derived water vapour for a five years period (1995-1999) prior to and during southwest monsoon is done over Indian subcontinent adjoining seas. Three layer (1000 hPa – 700 hPa, –500 500 -300 hPa) total moisture data available from NOAA/TOVS are used analysis. These study northward propagating intraseasonal oscillations in tropical Ocean summer season. Results indicate presence middle (700 upper level (500 300 vapour. Wavelet applied characteristics time evolution especially East Arabian Sea (EAS). Intraseasonal with periods ranging 8-15 days, 15-30 30-60 days seen EAS. Heavy rainfall events west coast peninsular India studied before after onset terms availability zonal wind speed. The content speed Eastern found influence India.