Camarinal (CS, see Fig. 1), that intercepts the Mediterranean outflow, and the
intense tidal currents [5–9] make this spot to gather optimal conditions for the
occurrence of this spectacular phenomenon, as it has been widely recognized
among the oceanographic community. This promoted the accomplishment of the
Gibraltar Experiment during the 1980s.
This international cooperative program provided further experimental evidences
of the small-scale structure of the internal waves and a theoretical frame to interpret
their life cycle. The generation was explained within the internal hydraulic theory of
the exchange through the Strait [10–12]. The comprehensive dataset collected
during the experiment suggested that the internal wave train was the time evolution
of a hydraulic jump regularly released on the west slope of CS that progresses
towards the Mediterranean Sea [11]. The phenomenon is triggered by the flooding
of the hydraulic control formed over CS [10, 11, 13], which occurs by the end of the
flood tide when tidal currents weaken [7, 11]. All this happens shortly before
the local high water due to the standing wave nature of the tide in the area [14]. The
spring-neap modulation of semidiurnal currents and the importance of diurnal tidal
currents [7], bring about fortnightly and diurnal variability on the flooding of the
Fig. 1 a Map of the Strait of Gibraltar and approaches sketching the path of the two main
Mediterranean water masses entering the strait. Camarinal Sill is indicated by the acronym CS.
b Detailed shaded bathymetry of CS area from [30] with indication of the accurate position of the
two deployed mooring lines (CSN and CSS, see also up and bottom insets). The two depressions at
the east (LB for Levante Basin) and west (PB for Poniente Basin) of CS mentioned in the text are
also indicated. c Detailed cross-section of CS showing the position of both mooring lines (which
are not to scale)
194
J. García-Lafuente et al.
intense tidal currents [5–9] make this spot to gather optimal conditions for the
occurrence of this spectacular phenomenon, as it has been widely recognized
among the oceanographic community. This promoted the accomplishment of the
Gibraltar Experiment during the 1980s.
This international cooperative program provided further experimental evidences
of the small-scale structure of the internal waves and a theoretical frame to interpret
their life cycle. The generation was explained within the internal hydraulic theory of
the exchange through the Strait [10–12]. The comprehensive dataset collected
during the experiment suggested that the internal wave train was the time evolution
of a hydraulic jump regularly released on the west slope of CS that progresses
towards the Mediterranean Sea [11]. The phenomenon is triggered by the flooding
of the hydraulic control formed over CS [10, 11, 13], which occurs by the end of the
flood tide when tidal currents weaken [7, 11]. All this happens shortly before
the local high water due to the standing wave nature of the tide in the area [14]. The
spring-neap modulation of semidiurnal currents and the importance of diurnal tidal
currents [7], bring about fortnightly and diurnal variability on the flooding of the
Fig. 1 a Map of the Strait of Gibraltar and approaches sketching the path of the two main
Mediterranean water masses entering the strait. Camarinal Sill is indicated by the acronym CS.
b Detailed shaded bathymetry of CS area from [30] with indication of the accurate position of the
two deployed mooring lines (CSN and CSS, see also up and bottom insets). The two depressions at
the east (LB for Levante Basin) and west (PB for Poniente Basin) of CS mentioned in the text are
also indicated. c Detailed cross-section of CS showing the position of both mooring lines (which
are not to scale)
194
J. García-Lafuente et al.