RT Journal Article
T1 Coupled echosounder and Doppler profiler measurements in the Strait of Gibraltar
A1 Sammartino, Simone
A1 García-Lafuente, Jesús
A1 Nadal Arizo, Irene
A1 Sánchez-Leal, Ricardo
K1 Corrientes marinas - Gibraltar (Estrecho)
AB Long time series of velocity profiles collected by up-looking acoustic profilers in the westernmost sill of the Strait of Gibraltar show an unexpected pattern in the deepest ∼80 m of the water column, consisting in an appreciable diurnal weakening of the measured horizontal velocity. A harmonic analysis performed on long time series reveals a surprising magnitude of S1 constituent (exactly 1 cpd of frequency) in the horizontal velocity and echo amplitude, which prevails over the rest of diurnal constituents within this depth range, including K1, despite being around 200 times smaller than it in the tide generating potential. High resolution echograms collected by a new instrument recently installed in the mooring line, point at the diel vertical migration of living acoustic scatterers (zooplankton) as the most reasonable cause. It provokes a nightly depletion of scatterers availability near the bottom, which is registered by the instrument as a nighttime weakening of the velocity, as well as an increase of its uncertainty, at the deepest part of the profile. Newly acquired high spatial resolution measurements of the velocity near the seafloor report intense currents which are incompatible with the ones produced by the scatterers scarceness. This result indicates an overall underestimation of the Mediterranean current in previous works of approximately 17% within the depth range of 280–360 m, which in turn translates into an underestimation of previously computed outflow of ∼5%. These new findings make it necessary the re-computation of all the near-20-year long (to date) series of Mediterranean outflow based on the observations collected at this sill of the Strait of Gibraltar.
PB Nature Research
YR 2024
FD 2024-12-28
LK https://hdl.handle.net/10630/36265
UL https://hdl.handle.net/10630/36265
LA eng
NO Sammartino, S., García-Lafuente, J., Nadal, I. et al. Coupled echosounder and Doppler profiler measurements in the Strait of Gibraltar. Sci Rep 14, 31261 (2024). https://doi.org/10.1038/s41598-024-82670-7
NO The work has been developed in the framework of the Project “EStación de Monitorización del Flujo de agua Mediterránea saliente por el Estrecho de GibraltaR: 4º periodo” (ESMER4), funded by the “Plan complementario de Ciencias marinas y del Plan de Recuperación, Trasnformación y Resiliencia” of Junta de Andalucía (Spain)—2023.
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 19 ene 2026