Adjoint observation impact system for COAMPS/NAVDAS

An adjoint observation impact system for the Naval Research Laboratory's (NRL) Coupled Ocean Atmosphere Prediction System (COAMPS) has been developed. The adjoint of COAMPS provides the gradient of forecast error with respect to the analysis fields to the adjoint model of the NRL Atmospheric Variational Data Assimilation in order to obtain the sensitivity to observation values. This system provides quantitative information on the value of observations in reducing forecast error. The system compares favorably with a similar system developed for NRL's global model on relatively large scales. Results from experiments investigating the impact of observations on the forecast error of relatively small scale atmospheric features will be presented at the conference.