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Ocean Science An interactive open-access journal of the European Geosciences Union
Ocean Sci., 11, 215-236, 2015
https://doi.org/10.5194/os-11-215-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
05 Mar 2015
Temperature–salinity distribution in the northeastern Atlantic from ship and Argo vertical casts
I. Bashmachnikov1,2, F. Neves1, Â. Nascimento1, J. Medeiros1, I. Ambar1,2, J. Dias1,2, and X. Carton3 1MARE – Marine and Environmental Sciences Centre/Centro de Oceanografia, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal
2Departamento de Engenharia Geográfica, Geofísica e Energia (DEGGE), Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal
3Laboratoire de Physique des Océans, UMR 6523, Université de Bretagne Occidentale, 6 avenue Le Gorgeu, 29200 Brest, France
Abstract. The present study defines new interpolation functions for hydrological data. These functions are applied to generate climatological maps of temperature–salinity distribution with a 25 m depth interval and a 30 km space interval (MEDTRANS data set). The data undergo rigorous initial data quality control, having passed several filtering procedures. The gridding is done on neutral density surfaces, which allows better representation of thermohaline fronts for the same gridding radius. The multi-pass Barnes optimum interpolation procedure with spatially variable size of the gridding window is used. The shape of the window accounts for the dominant along-isobath direction of water mass transport over steeply sloping topography. A local ratio of topographic to planetary β-effects is used to define the shape of the window as a function of the relative importance of the topographic influence. The N/f ratio is applied to account for the baroclinic compensation decay of the topographic influence on water mass transport with the distance from the bottom. The gridded fields are available at the website of the Centre of Oceanography of the University of Lisbon (http://co.fc.ul.pt/en/data).

The MEDTRANS climatology gives more details of the distribution of water characteristics in the subtropical northeastern Atlantic than other alternative climatologies and is able to reproduce a number of dynamic features described in the literature: the acceleration in the meanders of the Azores current; the cyclonic gyre in the Gulf of Cadiz; and the splitting and separation of the Mediterranean Water (MW) outflow in two veins near the Gorringe and Galicia banks. Seasonal climatologies, computed for the warm (May–October) and cold (November–April) seasons, reveal stronger zonal extension of the upper ocean patterns during the warm season, as compared to the cold one.


Citation: Bashmachnikov, I., Neves, F., Nascimento, Â., Medeiros, J., Ambar, I., Dias, J., and Carton, X.: Temperature–salinity distribution in the northeastern Atlantic from ship and Argo vertical casts, Ocean Sci., 11, 215-236, https://doi.org/10.5194/os-11-215-2015, 2015.
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The present study defines new interpolation functions for hydrological data. These functions are applied to generate climatological maps of temperature-salinity distribution with a 25m depth interval and a 30km space interval (MEDTRANS data set). The MEDTRANS climatology gives more details of the distribution of water characteristics in the subtropical northeastern Atlantic than other alternative climatologies and is able to reproduce a number of dynamic features described in the literature.
The present study defines new interpolation functions for hydrological data. These functions are...
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