Multi-Platform, High-Resolution Study of a Complex Coastal System: The TOSCA Experiment in the Gulf of Trieste

Abstract

Although small in size, the Gulf of Trieste (GoT), a marginal coastal basin in the northern Adriatic Sea, is characterized by very complex dynamics and strong variability of its oceanographic conditions. In April–May 2012, a persistent, large-scale anticyclonic eddy was observed in the GoT. This event was captured by both High Frequency Radar (HFR) and Lagrangian drifter observations collected within the European MED TOSCA (Tracking Oil Spill and Coastal Awareness) project. The complexity of the system and the variety of forcing factors constitute major challenges from a numerical modeling perspective when it comes to simulating the observed features. In this study, we implemented a high-resolution hydrodynamic model in an attempt to reproduce and analyze the observed basin-wide eddy structure and determine its drivers. We adopted the Massachusetts Institute of Technology General Circulation Model (MITgcm), tailored for the GoT, nested into a large-scale simulation of the Adriatic Sea and driven by a tidal model, measured river freshwater discharge data and surface atmospheric forcing. Numerical results were qualitatively and quantitatively evaluated against HFR surface current maps, Lagrangian drifter trajectories and thermohaline data, showing good skills in reproducing the general circulation, but failing in accurately tracking the drifters. Model sensitivity to different forcing factors (wind, river and tides) was also assessed.

Comparing the Currents Measured by CARTHE, CODE and SVP Drifters as a Function of Wind and Wave Conditions in the Southwestern Mediterranean Sea

“…Since the advent of satellite positioning and data telemetry in the late 1970s, instrumented buoys freely-drifting at the ocean surface have become increasingly popular to measure meteo-marine properties near the air–sea interface. In particular, they have been designed with a drogue to measure currents near the ocean surface, with varying levels of accuracy, by tracking their positions in time in order to investigate upper ocean dynamics over a wide range of spatial scales, from the global ocean [ 1 , 2 ] to marginal seas [ 3 , 4 , 5 ] and small coastal areas [ 6 , 7 ], and at time scales of hours to decades.…”

Monitoring System of the Mar Menor Coastal Lagoon (Spain) and Its Watershed Basin Using the Integration of Massive Heterogeneous Data

“…Coastal observatories that integrate different technologies are spreading in several countries in our environment to monitor eutrophication processes; some examples are the coastal observatory in the bay of Kalloni Bay in Greece [7] or the one developed in the Gulf of Trieste by the MED TOSCA project in Italy [8].…”