Estimation of Bottom Friction Coefficients Based on an Isopycnic-Coordinate Internal Tidal Model with Adjoint Method

Abstract EN

Based on an isopycnic-coordinate internal tidal model with the adjoint method, three groups of ideal experiments are carried out in order to investigate the estimation of spatially varying bottom friction coefficients (BFCs).

In group 1, five values of distance between independent points (DIP) are used to invert the BFCs with the distribution of conical surface.

Results show that the BFCs can be inverted successfully with independent point scheme and the strategy with a DIP of 50′ can yield the best results.

In group 2, five values of interpolation radius (IR) are used to invert the BFCs with the distribution of conical surface.

Results show that the strategy with an IR of 1.9 times of DIP can yield the best results.

Based on the results of the first two groups, group 3 adopts the optimal DIP and IR to estimate 4 kinds of spatially varying BFCs.

The results indicate that the isopycnic-coordinate internal tidal model with the adjoint method has a good ability to estimate the spatially varying BFCs; the inversion results of the BFCs with the distribution of revolution paraboloid are better than those with the distribution of conical surface.