  A variational data assimilation technique was used to estimate optimal
discretization of interpolation operators and derivatives in the nodes adjacent
to the rigid boundary. Assimilation of artificially generated observational
data in the shallow-water model in a square box and assimilation of real
observations in the model of the Black sea are discussed. It is shown in both
experiments that controlling the discretization of operators near a rigid
boundary can bring the model solution closer to observations as in the
assimilation window and beyond the window. This type of control allows also to
improve climatic variability of the model.

Atmospheric and Oceanic Physics;Optimization and Control