On the level of least motion and the circulation in the upper layers of the Bay of Bengal

Abstract

The paper presents the circulation pattern in the upper 500 metres of the western Bay of Bengal between 9 degrees N and 16 degrees N during the south-west monsoon period, based on the geo-potential anomalies computed from the hydrographic data. The circulation is characterised by two anti-cyclonic cells centred at 11 degrees N 83 degrees E and 16 degrees N 85 degrees E with a zone of strong cyclonic shear between them. The strength of the circulation decreases with depth and it becomes feeble below a depth of 400 metres. The level of least motion is situated around 500 metres depth. The methodology in choosing the reference level is discussed.