Use of ocean model forecasts during acoustic experiments and naval missions

Abstract

Ocean acoustic propagation is critically dependent upon the spatial (and to a lesser extent the temporal) scales of the ocean. With the advent of high-fidelity data-assimilative ocean models, forecasts are available that can provide an improved level of confidence for acoustic propagation modeling in support of sea-tests and naval exercises. In this paper, a set of experiments will be presented where ocean model forecasts were used within an acoustic model to help inform the experiment planning. Tests include shallow water tests (Key West), continental shelf-break environments (Shallow Water 2006, Quantifying and Predicting Uncertainty) and deep water environments (Philippine sea 2009/2010). Models used include the Navy Coastal Ocean Model (NCOM), the MSEAS model (MIT, Pierre Lermusiaux), the ECCO2 model state estimation and the Scripps Institution of Oceanography version of the ROMS (Bruce Cornuelle) model run. In-situ assimilation of acoustic signals was performed for geo-acoustic information (in shallow water) and not for ocean model forecast updates. Our conclusion for over 10 years of use of models in real-time experiments is that ocean model forecasting does provide useful information for mission planning and experiment design, particularly when combined with on-site measurements.