Inverse estimation of open boundary conditions in tidal channels

This article presents a novel algorithm for the estimation of open boundary conditions in river systems where tidal forcing is present. This algorithm uses a linearisation of the model equations. With the help of a linear discretisation scheme, the article presents a quadratic programming formulation of the estimation problem in which the control variables are the coefficients of the dominant tidal modes. This method is implemented for a scenario in which only Lagrangian observations from drifters are available to measure flow quantities. The performance of the algorithm is evaluated using numerical experiments and comparing estimation results with boundary conditions from a river located in the Sacramento Delta. The sensitivity of the algorithm to the number of modes estimated and its predictive capabilities are also assessed.