ISSN 2070-7401 (Print), ISSN 2411-0280 (Online)
Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa


Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2016, Vol. 13, No. 6, pp. 75-85

Wave-induced upwelling over the Mid-Atlantic Ridge near the Azores front

V.A. Melnikov 1 
1 P.P. Shirshov Institute of Oceanology RAS, Moscow, Russia
Accepted: 07.10.2016
DOI: 10.21046/2070-7401-2016-13-6-75-85
In the paper, the mesoscale variability in the Azores front domain over the Mid-Atlantic Ridge, south-west of the Azores, is considered on the basis of hydrophysical in-situ measurements acquired during an expedition of the Institute of Oceanology RAS (31 cruise of r/v “Akademik Kurchatov”), in April-July 1980, in the square 27-37N, 27-40W, with the use of modern satellite data of ocean surface temperature (Pathfinder, v5, 1981–2007), sea level anomalies (Aviso, 1993-2015) and ETOPO-1 model of ocean depths. Three (for a two-month period) consecutive hydrological surveys, instrumental measurements of currents and temperatures using 13 moorings for a total period of about 1.5 months, upper 500-meter layer temperature sections along the vessel route by means of expendable bathythermographs, as well as modeling of processes, made it possible to interpret the temperature field observed over the Mid-Atlantic Ridge as semidiurnal first mode internal waves with a wavelength horizontal scale ~ 120 km, propagating to the south-east from the ridge axis. In the satellite data of ocean surface temperature field, the cold water strips (100 km wide and 500 km long) were permanently observed, being stretched along the semidiurnal internal wave phase contours parallel to the ridge axis. Joint analysis of the contact and remote sensing data showed that these cold bands arise due to the upwellings caused by the internal wave. Wave upwellings have a significant impact on the process of mixing of water masses of temperate latitudes and subtropical waters in the Azores front area.
Keywords: field measurements, Mid-Atlantic Ridge, subtropical gyre, water masses, Azores front, Azores Current, mesoscale variability, internal tidal waves, bottom topography flow regimes, wave upwelling, diapycnal mixing, satellite data, sea surface temperature, sea level anomalies, bottom topography ETOPO1 model.
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