NAVDAS-AR for COAMPS

A four dimensional variational data assimilation system is under development for the Naval Research Laboratory's (NRL) Coupled Ocean Atmosphere Prediction System atmospheric model. The observation based representer method developed for NRL's global model is used as a framework for the limited area model system. A tangent linear and adjoint model are used to propagate information forward and backward, respectively, in time during the assimilation window. The background error covariance is modeled using a diffusion operator method. The system has been tested by ensuring that the reprensenter matrix formed by the system for a small number of observations is symmetric. Results from data assimilation experiments will be presented.