Adjoint data assimilation into a 3D unstructured mesh coastal finite element model

An adaptive mesh adjoint model has been developed to invert for uncertain parameters in the simulation of coastal flows. These may include, for example, open boundary conditions and initial conditions. Our objective in this paper is to obtain a better representation of water flows around and over coastal topography. In this paper a first attempt has been made at using mesh adaptivity in both transient forward and adjoint models. Although the resulting method has inconsistent discrete schemes for the forward and adjoint models, the inversion results shown here arc nevertheless good. The derivation of the continuous adjoint model is presented. A description of the adaptive mesh adjoint technique is also given. As a study case, the method is applied to the inversion of boundary conditions for flow past a headland.