section is usually referred to as “approach control” in the literature of internal
hydraulics ([28, 29], Sect. 5), and would be formed over the very sill a short
distance upstream of the crest of CS (Fig. 2a). Moreover, the associated upstream
jump is much more apparent in CSS as revealed by the referred model simulation
and satellite images (see Fig. 1 of Sánchez Garrido et al. [13] for a nice illustration
of the situation).
It is hypothesized here that the high-frequency stripes of marked variance that
shift upwards with the interface (Fig. 8b) are connected to the growing of this
second jump. When the flood current weakens and the hydraulic controls are lost,
the released internal bores eventually merge together and move eastwards as a
unique feature (Fig. 2b, c). However, within this scenario, it appears that only the
very energetic bore released by the main jump is specifically noticed at CSS, its
footprint being the sudden westward pulse of the deep already mentioned (labels
(5) in Fig. 6b). Similar traces are not seen so clearly in CSN, where the signal is
much more blurred, though still weakly discernible, and concentrates in the upper
water column in CSN (Figs. 5a and 8a).
Acknowledgements Data were collected in the frame of the Spanish Government-funded
“INGRES-3” (CTM2010-21229/MAR) and “ENCIBA” (CTM2013-40886P) projects. We are
particularly grateful to the Instituto Español de Oceanografía, which allocated ship-time of the
research vessel Ángeles Alvariño for carrying out the field experiment. This experiment is also part
of the PE12-RNM-1540 Regional Government of Junta de Andalucía Excellence project. CN
acknowledges a research contract associated with CTM2013-40886P project. JCSG was partially
supported by the “Juan de la Cierva” program (contract JCI-2012-13451) and SS acknowledges a
post-doc contract linked to PE12-RNM-1540 project.
References
1. Jackson, C. R. (2004). An Atlas of internal solitary-like waves and their properties (2nd ed.).
Alexandria, VA: Global Ocean Associates.
2. La Violette, P., & Lacombe, H. (1988). Tidal-induced pulses in the flow through the strait of
Gibraltar. Oceanologica Acta (Special issue, Édn. scientifiques et médicales Elsevier SAS).
3. Lacombe, H., & Richez, C. (1982). The regime of the strait of Gibraltar. In: Jacques CJN
(Ed) Elsevier oceanography series (pp 13–73). Elsevier.
4. Ziegenbein, J. (1970). Spatial observations of short internal waves in the strait of Gibraltar.
Deep Sea Research and Oceanographic Abstracts, 17, 867–875. https://doi.org/10.1016/
0011-7471(70)90004-5.
5. Bryden, H. L., Candela, J., & Kinder, T. H. (1994). Exchange through the Strait of Gibraltar.
Progress in Oceanography, 33, 201–248. https://doi.org/10.1016/0079-6611(94)90028-0.
6. Candela, J., Winant, C., & Ruiz, A. (1990). Tides in the strait of Gibraltar. Journal of
Geophysical Research: Oceans, 95, 7313–7335. https://doi.org/10.1029/JC095iC05p07313.
7. García Lafuente, J., Vargas, J. M., Plaza, F., et al. (2000). Tide at the eastern section of the
strait of Gibraltar. Journal of Geophysical Research: Oceans, 105, 14197–14213. https://doi.
org/10.1029/2000JC900007.
8. Morozov, E. G., Parrilla-Barrera, G., Velarde, M. G., & Scherbinin, A. D. (2003). The straits
of Gibraltar and Kara gates: a comparison of internal tides. Oceanologica Acta, 26, 231–241.
https://doi.org/10.1016/S0399-1784(03)00023-9.
208
J. García-Lafuente et al.
hydraulics ([28, 29], Sect. 5), and would be formed over the very sill a short
distance upstream of the crest of CS (Fig. 2a). Moreover, the associated upstream
jump is much more apparent in CSS as revealed by the referred model simulation
and satellite images (see Fig. 1 of Sánchez Garrido et al. [13] for a nice illustration
of the situation).
It is hypothesized here that the high-frequency stripes of marked variance that
shift upwards with the interface (Fig. 8b) are connected to the growing of this
second jump. When the flood current weakens and the hydraulic controls are lost,
the released internal bores eventually merge together and move eastwards as a
unique feature (Fig. 2b, c). However, within this scenario, it appears that only the
very energetic bore released by the main jump is specifically noticed at CSS, its
footprint being the sudden westward pulse of the deep already mentioned (labels
(5) in Fig. 6b). Similar traces are not seen so clearly in CSN, where the signal is
much more blurred, though still weakly discernible, and concentrates in the upper
water column in CSN (Figs. 5a and 8a).
Acknowledgements Data were collected in the frame of the Spanish Government-funded
“INGRES-3” (CTM2010-21229/MAR) and “ENCIBA” (CTM2013-40886P) projects. We are
particularly grateful to the Instituto Español de Oceanografía, which allocated ship-time of the
research vessel Ángeles Alvariño for carrying out the field experiment. This experiment is also part
of the PE12-RNM-1540 Regional Government of Junta de Andalucía Excellence project. CN
acknowledges a research contract associated with CTM2013-40886P project. JCSG was partially
supported by the “Juan de la Cierva” program (contract JCI-2012-13451) and SS acknowledges a
post-doc contract linked to PE12-RNM-1540 project.
References
1. Jackson, C. R. (2004). An Atlas of internal solitary-like waves and their properties (2nd ed.).
Alexandria, VA: Global Ocean Associates.
2. La Violette, P., & Lacombe, H. (1988). Tidal-induced pulses in the flow through the strait of
Gibraltar. Oceanologica Acta (Special issue, Édn. scientifiques et médicales Elsevier SAS).
3. Lacombe, H., & Richez, C. (1982). The regime of the strait of Gibraltar. In: Jacques CJN
(Ed) Elsevier oceanography series (pp 13–73). Elsevier.
4. Ziegenbein, J. (1970). Spatial observations of short internal waves in the strait of Gibraltar.
Deep Sea Research and Oceanographic Abstracts, 17, 867–875. https://doi.org/10.1016/
0011-7471(70)90004-5.
5. Bryden, H. L., Candela, J., & Kinder, T. H. (1994). Exchange through the Strait of Gibraltar.
Progress in Oceanography, 33, 201–248. https://doi.org/10.1016/0079-6611(94)90028-0.
6. Candela, J., Winant, C., & Ruiz, A. (1990). Tides in the strait of Gibraltar. Journal of
Geophysical Research: Oceans, 95, 7313–7335. https://doi.org/10.1029/JC095iC05p07313.
7. García Lafuente, J., Vargas, J. M., Plaza, F., et al. (2000). Tide at the eastern section of the
strait of Gibraltar. Journal of Geophysical Research: Oceans, 105, 14197–14213. https://doi.
org/10.1029/2000JC900007.
8. Morozov, E. G., Parrilla-Barrera, G., Velarde, M. G., & Scherbinin, A. D. (2003). The straits
of Gibraltar and Kara gates: a comparison of internal tides. Oceanologica Acta, 26, 231–241.
https://doi.org/10.1016/S0399-1784(03)00023-9.
208
J. García-Lafuente et al.