Tidal Influence on the Seasonal Variation in Current and Salinity around Willingdon Island

Abstract

The general distribution of current and salinity of Mattancherry and Ernakulam channels and the Cochin Harbour mouth, Kerala, India is presented and discussed in relation to the tide. During monsoon season stratification is observed. The salinity varies from 5 ppt at the surface to 25 ppt at the bottom during flood tide. The flood and ebb currents are comparatively high in the Ernakulam channel than in the Mattancherry channel. The ebb currents are strong in the surface layers and the flood currents at the bottom layers. During premonsoon season no stratification is observed from surface to the bottom. The salinity varies from 32.0 to 36.5 ppt. The highest velocity of the ebb and flood currents is found at the surface layers. The velocity of the currents directly depends on the range of the tide. The highest velocities encountered in both the channels are found to be of the same order, around 70 cm/sec