Amplified Msf tides at Kochi backwaters on the southwest coast of India

Characteristics of tides at eight stations in Kochi backwaters (KB) located on the southwest coast of India are analysed. The Msf tidal constituents at several locations are found to be considerably larger than those estimated from the driving tidal potential. The Msf tidal amplitude amplifies progressively from Kochi inlet to the shallower upstream region where it exhibits ~3-fold amplification. At the upstream boundary, the Msf tide has the same order of magnitude as M₂ and K₁ tides. The nonlinear frictional interaction between M₂ and S₂ tides appears to be mainly responsible for the observed amplification. However, in regions where depth is