Enhancement of internal tides on the continental slope of northeastern Arabian Sea during winter

Mooring observations and simulations from a high-resolution numerical ocean model were utilised to study the seasonality of internal tides in the northeastern Arabian Sea. Observations show intensification of internal tides in winter in the deep part of the eastern Arabian Sea compared to summer. Model simulation shows that the shelf-break and deep slope are the major generation sites. In winter, the model shows multiple generation sites along the continental slope compared to summer. Stratification shows that the shelf favours internal tide generation during summer compared to winter. However, stratification does not show a significant difference between winter and summer on the slope, whereas the position of the pycnocline varies according to the season. During winter (summer), the pycnocline deepens (shoals) and the width reduces (increases). Sensitivity experiments using a simple two-dimensional model show that, during winter, the deep thin pycnocline facilitates strong IT generation in the slope region.