Daisy P. García awarded “Modesto Vigueras 2022” price second place for her research developed during her internship at SOCIB

Daisy P. García is a graduate in Marine Sciences from the University of Cadiz (UCA) and she has recently won the second “Modesto Vigueras 2022” Award sponsored by the Technical Association of Ports and Coast (ATPYC). These awards are given to recognize young researchers, aiming to encourage interest and specialisation to the new generations of professionals in the port and coastal sectors, the development of new ideas in these fields as well as to engage them to participate in the ATPYC activities.

Her work entitled “Particle retention processes at the NW coastal margin of the Strait of Gibraltar using HFR measurements” was developed by Daisy during her internship period at the Balearic Islands Coastal Observing and Forecasting System (SOCIB). This Internship was conducted under the co-supervision of Dr. Emma Reyes (Head of SOCIB Coastal HF Radar facility) and Dr. Marina Bolado (substitute lecturer at the Department of Applied Physics, University of Cadiz), within the context of the Educational Cooperation Agreement between both institutions.

Daisy P. García - Particle retention processes at the NW coastal margin of the Strait of Gibraltar using HFR measurements

“The main objective of this study has been to analyze the joint influence of tidal and wind forcing on the surface transport processes responsible for the high residence times in the north-western coastal margin of the Strait of Gibraltar”.

To achieve this objective, the work was based on the estimation of the escape times of virtual particles from the reconstructed current measurements provided by the high-frequency radar network (HFR) of the Strait of Gibraltar (HFR-Gibraltar), which operates Puertos del Estado.

“The reconstruction of the surface current hourly field measured by the HFR-Gibraltar has been carried out by applying the OMA gap-filling methodology (Open-Boundary Modal Analysis). Virtual particles were then daily advected on the reconstructed current fields (in a 1x1 km2 regular grid) to simulate their Lagrangian trajectories, using different Lagrangian models and including a normal-push-to-the-coast to prevent the escape of the particles through the coastal boundaries”.

The escape time of the particles launched within the 50 m depth contour of the north-western margin of the Strait of Gibraltar has been estimated, based on the simulated trajectories, following the methodology described by Rubio et al., (2020)”.

The highest escape times (i.e. time taken by the particles from the north-western margin of the Strait until they leave the defined domain) correspond to two scenarios: i) under easterly wind and neap tide conditions, due to a general water retention in the western side of the Strait and ii) under westerly wind and spring tide conditions, due to the generation of coastal cyclonic vortices.

“It is worth highlighting that the methodology of estimation of the escape times of the present work has direct applications to the preservation of coastal and port water quality. In fact, under the legislative framework of the EU Water Framework Directive (WFD; 2000/60/EC), the residence water times is a standard descriptor of the transport processes used as an indicator to assess the water quality and typify the ecological status of surface waters. Therefore, improving knowledge about these processes is crucial: e.g. to define the optimal point and moment of discharge from Wastewater Treatment Plants; to oil spill response; to select the location of aquaculture farm facilities and plan sanitation management (Roarty et al., 2019); or to monitor and predict the trajectory of invasive species, jellyfish, larvae or nutrients, etc."