Wave and Current Regime off the Southwest Coast of India.

Waves and currents recorded off Chavara, southwest coast of India, over a period of 2 years are used to understand the wave-current regime of this monsoon dominated coast. The waves during monsoon are characterised by higher heights, shorter periods, and are confined to westerly directions. The wave characteristics indicate nearby generation. The premonsoon and postmonsoon waves are characterised by lower heights and higher periods with the direction being more southerly. Waves arrive from a wider range of generating areas during the fair weather periods, particularly during the premonsoon months. The wave heights exhibit yearly variations, but the periods and directions remain relatively constant. Like the waves, the currents also show seasonal changes with stronger currents during monsoon and weaker currents during fair weather. The alongshore components of the currents are mostly much stronger than the cross-shore flows and the pattern is mostly diurnal although a semidiurnal signal is also readily apparent, the latter associated with tidal currents. The diurnal activity is mostly wind-induced. In the monsoon season, the dominant direction is southerly to southwesterly, whereas during the premonsoon and postmonsoon it varies between northwest and southeast. Notable deviations to the generally understood pattern of southerly currents during monsoon and northerly currents during fair weather are observed. This could be attributed to the reported occurrence of a cyclonic eddy during monsoon and anticyclonic eddy during fair weather in the Lakshadweep Sea. [ABSTRACT FROM AUTHOR]