%0 Journal Article 
%A García Steinebronn, Daisy Pemba
%T Particle retention at the northwestern coastal margin of the Strait of Gibraltar with the estimation of residence times using HFR measurements

%D 2021
%U http://hdl.handle.net/10498/25532
%X This work analyses the influence of wind and tidal conditions on the surface transport
processes at the western side of the Strait of Gibraltar (SoG), particularly those
responsible for the high residence times at the coastal margin. The study of the
hydrodynamic patterns has been done with the computation of particle trajectories and
residence time maps, using the High Frequency Radar (HFR) current measurements
provided hourly by the Gibraltar network. The inclusion of the recently installed
Camarinal Station in the gap-filling methodology (Open-boundary modal analysis, OMA)
previously applied, needed for the Lagrangian approach, makes it the first work to
completely cover the SoG with a gap-free 2D HFR current field.
The resulting OMA nowcast has reconstructed the surface current field, being them highly
correlated -(Ru=0.93; Rv=0.88)- with the patterns provided by the totals, and it has also
shown to have a high potential for Lagrangian diagnoses, as a first approximation. It has
offered the possibility to visualize (sub)mesoscale structures already described in
previous studies (e.g cyclonic gyres at the coastal margin; suction of particles to the
central channel) and others not so well known (e.g coastal countercurrent; transversal
transport from South to North). Moreover, the transport properties have been related to
the joint effect of tidal and wind forcing (e.g westerlies and spring tides contribute to the
positive vorticities at the coastal margin East of Trafalgar and between Paloma Point and
Tarifa; easterlies and neap tides increase the residence time on the western side). All
together, these processes contribute to increase the retention of enriched waters at the
western side of the SoG explaining the high chlorophyll concentrations detected in other
studies.

%K HFR_Progs
%K High Frequency Radar
%K Lagrangian trajectories
%K Open-boundary Modal Analysis (OMA)
%K particle tracking
%K residence time
%K surface currents
%K Strait of Gibraltar
%K (sub)mesoscale
%~ Universidad de Cádiz