Coupled ocean-atmosphere nested modeling of the Adriatic Sea during winter and spring 2001

Abstract

Realistic simulations of the Adriatic Sea for over 125 days are conducted using the Navy Coastal Ocean Model with atmospheric forcing provided by the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS is a registered trademark of the Naval Research Laboratory (COAMP™)). In two separate simulations of the Adriatic, a nested 2-km-resolution ocean model is forced by the inner (4-km) and outer (36-km) nests of the atmospheric model. Two meteorological stations and two acoustic Doppler current profiler observation sites are used to evaluate modeled atmosphere and ocean velocity fields for 28 January-4 June 2001. Modeled/observed correlations of atmospheric 10-m velocity are greater than 0.85 for both resolution models. Oceanic 5- and 25-m current fluctuations from both simulations generally match the magnitude and orientation of the observations. The 4-km-resolution atmospheric model is differentiated from the 36-km-resolution model by its ability to resolve the small-scale flow structures of the "bora" wind and by its better agreement with observed wind velocity statistics. The ocean simulation forced by the 4-km-resolution model is distinguished from the one forced by the 36-km-resolution model by its ability to reproduce the expected double-gyre circulation in the northern Adriatic and by its ability to better capture the magnitude and shape of the observed depth-dependent velocity correlation with wind at the deeper site. Though the 36-km forced ocean model agrees better with many observed velocity statistics, the 4-km forced ocean model produces the highest correlations with observations (exceeding 0.78) at subsurface depths that are most strongly correlated with winds.