Simulation of the northern Adriatic circulation during winter 2003

Abstract

Numerical simulations of the Adriatic Sea were conducted with the Navy Coastal Ocean Model during the Adriatic Circulation Experiment in the fall and winter of 2002/2003, and results were compared with observations. The ocean model used a 1‐km resolution grid over the entire Adriatic Sea. Model forcing included atmospheric fluxes from the Coupled Ocean‐Atmosphere Mesoscale Prediction System (COAMPS), tides, boundary conditions from a global model, and freshwater river and runoff inflows. Model tidal elevation showed good agreement with International Hydrographic Organization station data, and model tidal currents showed good agreement with tidal currents determined from acoustic Doppler current profiler (ADCP) measurements. Detided model currents showed good agreement with ADCP currents with rms errors along the principal variance axes ranging from 6 to 12.9 cm/s and correlations ranging from 0.16 to 0.81. Correlations between model and ADCP currents along the minor variance axes were generally low. Comparison of the model‐simulated temperature and salinity profiles during January and February with conductivity‐temperature‐depth measurements indicated that the model captured some of the spatial structure of the observed fields. The model response to several bora wind events in January and February showed a recurring pattern of cyclonic and anticyclonic gyres that generally agreed with observations and reflected the pattern of wind stress curl from the COAMPS wind stress forcing. During strong bora forcing, two large cyclonic circulation gyres form in the northern Adriatic with a smaller anticyclonic circulation between them near the Istrian Peninsula. Additionally, a couple of large meanders frequently occur within the Eastern Adriatic Current southeast of Kvarner Bay, and these meanders sometimes close to form small gyres.