Ocean circulation studies (Alborán Sea, Balearic Sea, etc) : Climate – ocean interactions and their impact on marine ecosystems are worldwide attention particularly for coastal, semi-enclosed and marginal seas in which masking of natural climatic variations by those introduced through heavy human interventions is a major concern. Understanding their climate change and climatic variations strongly requires elucidating dominant spatial and temporal modes of variability and their interactions and feedbacks. In particular, processes involved in the annual cycle, their dominant mode of variability, may likely trigger variability on width range of time scales (interannual to interdecadal) and can as well be modulated by longer time scale variability through feedback mechanisms. the Alborán Sea of the Western Mediterranean is a highly dynamic system known to exhibit complex set of interactions arising from local, regional and hemispherical processes, and therefore serves as a good global example for semi-enclosed seas .
As a first step, by analysing remote sensing data, the main robust features of the Alborán Sea have been assesed. Please find bellow the abstract of this study.
Surface circulation in the Alborán Sea (Western Mediterranean) inferred from remotely sensed data
L. Renault(1), T. Oguz(1,2), A. Pascual(3), G. Vizoso(1,3), J. Tintore(1,3)
(1) ICTS SOCIB, Parc Bit, Naorte, Bloc A 2ºp. pta. 3, Palma de Mallorca, SPAIN. (2) METU, Institute of Marine Sciences, 33731Erdemli, Mersin, TURKEY, (3) IMEDEA (UIB-CSIC) - C/ MiquelMarquès 21, 07190 Esporles, SPAIN
n this study, for the first time at regional scale, the combined use of remote sensing data (altimetry and sea surface temperature records) provides a description of the persistent, recurrent and transient circulation regimes of the Alborán Sea circulation. The analysis of 936 altimeter-derived weekly absolute dynamic topography (ADT) and surface geostrophic current maps for 1993–2010 reveals the presence of a dominant annual signal and of two interannual modes of variability. The winter-spring phase is characterized by two stable gyral scale features; the well-known Western Anticyclonic Gyre within the western area and the Central Cyclonic Gyre, a new structure not identified in former studies, occupying the central and eastern parts of the Alborán Sea. A double anticyclonic gyre regime constitutes the stable circulation system of the summer–autumn period when the Eastern Anticyclonic Gyre is formed within the eastern Alborán basin. In this case, the Central Cyclonic Gyre is narrower and located closer to the Western Anticyclonic Gyre. They represent two stable states of the system, robust at the decadal time scale, whereas transient changes reflect perturbations on these stable states and are mainly observed at an interannual scale. The circulation variability and the gyral features development may be dynamically linked to the corresponding changes of the Gibraltar transport rates.
Citation: (2012), Surface circulation in the Alborán Sea (western Mediterranean) inferred from remotely sensed data, J. Geophys. Res., 117, C08009, doi:10.1029/2011JC007659.
