Surface circulation in the Gulf of Trieste (northern Adriatic Sea) from radar, model, and ADCP comparisons

• Published in: Journal of geophysical research. Oceans 2013-11, Vol.118 (11), p.6183-6200
• Main Authors: Cosoli, Simone, Ličer, Matjaž, Vodopivec, Martin, Malačič, Vlado
• Format: Article
• Language: English
• Subjects: Adriatic Sea; Circulation; Complement; Computer simulation; Diurnal variations; Earth, ocean, space; Exact sciences and technology; External geophysics; Geophysics; Gulfs; HF coastal radars; Marine; Mathematical models; Meteorology; Ocean circulation; ocean circulation models; Oceans; Physics of the oceans; Radar; Surface circulation
• ISSN: 2169-9275; 2169-9291
• DOI: 10.1002/2013JC009261

High resolution high frequency (HF) radar observations of surface currents in the Gulf of Trieste (GoT) are presented and compared to moored subsurface current measurements and to high‐resolution simulations from the Northern Adriatic Princeton Ocean Model (NAPOM) oceanographic model. Dominant circulation modes of the GoT were resolved and numerical model capabilities in reconstructing them were assessed. The time frame covers March 2011 through October 2012. NAPOM reconstructs the dominant surface circulation features observed by the radar, such as the general basin‐wide cyclonic circulation scheme and the coastal jet outflowing the GoT, but is in general less energetic than radar currents. Comparisons between radar, ADCP, and model currents suggest that the model underestimates originate within the low‐frequency, diurnal, semidiurnal, and inertial bands, and that both radar and model currents do not reproduce the diurnal tidal ellipse structure observed by the moored current meter. However, radar‐model results for the semidiurnal tides are spatially consistent. Using empirical orthogonal function (EOF) decomposition, the coherent spatial scales and corresponding temporal scales were extracted. Findings suggest that HF radar current observations complement model simulations in regions of enhanced topographic variability where variance of model currents at the surface is distorted by the effects of the sigma layer grid. On the contrary, model results complement radar observations in areas with poor radar coverage, and furthermore provide spatial and temporal continuity of ocean state forecasts. Key Points Dominant surface current patterns in the Gulf of Trieste were studied Capabilities of high‐resolution regional circulation model were assessed HF radars and model are complementary tools for identifying circulation features