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In this paper, a detailed description of the roadmap to transform four individual CODAR SeaSonde high-frequency (HF) radars into an integrated HF radar network operated by Puertos del Estado (Madrid, Spain) is provided. To assess the maturation process into a fully operational status, the system must evolve via an implementation of phased approaches, including: homogenization of maintenance practices, quality control checks in real time, standardization of data access, and development of customized visualization tools. Additionally, continuous validation works with independent in situ sensors are required to provide upper bounds on both radial and total radar current measurement accuracies. Consistent correlation coefficients and uncertainty values emerge in the range of 0.31–0.81 and 8–22 cm/s, respectively, for the remotely estimated velocities. Complementarily, a dedicated online website has been developed to operationally monitor radar system health in real time. This automated quality control application analyzes a number of diagnose parameters to obtain estimates of their standard ranges and evaluate radar site performance according to them. Abrupt changes, gradual degradation, and/or failure problems can be easily detected, triggering alerts for troubleshooting. Once a good performance of HF radar systems is ensured, 2-D surface current maps are used for a broad range of practical applications, i.e., search-and-rescue operations, oil spill response, or the rigorous skill assessment of an operational ocean forecasting system such as Iberia–Biscay–Ireland (IBI), implemented within the frame of the Copernicus Marine Environment Monitoring Service. [ABSTRACT FROM AUTHOR]

In this work, the benefits of high-frequency (HF) radar currents for oil spill modeling and trajectory analysis of floating objects are analyzed. The HF radar performance is evaluated by means of comparison between a drifter buoy trajectory and the one simulated using a Lagrangian trajectory model. A methodology to optimize the transport model performance and to calculate the search area of the predicted positions is proposed. This method is applied to data collected during the Galicia HF Radar Experience. This experiment was carried out to explore the capabilities of this technology for operational monitoring along the Spanish coast. Two long-range HF radar stations were installed and operated between November 2005 and February 2006 on the Galician coast. In addition, a drifter buoy was released inside the coverage area of the radar. The HF radar currents, as well as numerical wind data were used to simulate the buoy trajectory using the TESEO oil spill transport model. In order to evaluate the contribution of HF radar currents to trajectory analysis, two simulation alternatives were carried out. In the first one, wind data were used to simulate the motion of the buoy. In the second alternative, surface currents from the HF radar were also taken into account. For each alternative, the model was calibrated by means of the global optimization algorithm SCEM-UA (Shuffled Complex Evolution Metropolis) in order to obtain the probability density function of the model parameters. The buoy trajectory was computed for 24h intervals using a Monte Carlo approach based on the results provided in the calibration process. A bivariate kernel estimator was applied to determine the 95% confidence areas. The analysis performed showed that simulated trajectories integrating HF radar currents are more accurate than those obtained considering only wind numerical data. After a 24h period, the error in the final simulated position improves using HF radar currents. Averaging the... [Copyright &y& Elsevier]

Hydrographic data define source regions for deep, intermediate and upper-ocean water types found near the northwest Iberian margin; these water masses'' structure and geostrophic flow are described. Labrador Sea Water (LSW) moves south through the region; above this at 1000 m, particularly near the coast, Mediterranean Sea Outflow Water (MSOW) moves north. Near-surface waters are more seasonal, and we distinguish summer and winter regimes.Summer: above 600 m, poleward flow over the slope is at a minimum in spring and summer, and a maximum in the autumn/early winter. Overlying this is a general southward flow linked to wind stress. Summer upwelling along the Iberian shelf has associated offshore filaments stretching westward, and appears most intense around Finisterre (starting earlier, more persistent). The vertical upwelling flux is τ/ρf but lateral exchange in filaments may be more.Winter: it is proposed that upper layers of the water column offshore are fed from the north. Potential vorticity calculations suggest enhanced diapycnic mixing. However, other data indicate an east–west front down to about 300 m at 39–40°N, i.e., north–south convergence. This front bends to the north near the shelf edge, in accord with a warm flow along the upper slope, 0.15 m/s or more. Surface temperatures often show a much broader (hundreds of kilometers) northward extension of warm water, probably affected by winds. The thermocline from the previous summer can persist to January at least. Coastal waters show cooler river runoff.Budgeting of water fluxes is discussed in relation to direct estimates (from water mass properties and current measurements) and in relation to possible process contributions to fluxes. On/off-shelf exchange has a relatively short time scale, estimated at about 12 days. Upwelling (mostly) and mixing may supply the nutrient content of about 200 m water depth for new production over the shelf. [Copyright &y& Elsevier]