Description and mechanisms of the mid-year upwelling in the southern Caribbean Sea from remote sensing and local data

TitleDescription and mechanisms of the mid-year upwelling in the southern Caribbean Sea from remote sensing and local data
Publication TypeManuscript
Year of Publication2018
AuthorsRueda-Roa D, Ezer T, Muller-Karger F
Collection TitleJournal of Marine Science and Engineering
Volume/Storage Container6(2), 36
Manuscript Number275474
KeywordsCARIACO Ocean Time-Series Program., Coastal Upwelling, Ekman Pumping/Suction; wind-curl, Ekman Transport, remote sensing, SST Caribbean Sea
Abstract

The southern Caribbean Sea experiences strong coastal upwelling between December and April due to the seasonal strengthening of the trade winds. A second upwelling was recently detected in the southeastern Caribbean during June–August, when local coastal wind intensities weaken. Using synoptic satellite measurements and in situ data, this mid-year upwelling was characterized in terms of surface and subsurface temperature structures, and its mechanisms were explored. The mid-year upwelling lasts 6–9 weeks with satellite sea surface temperature (SST) ~1–2° C warmer than the primary upwelling. Three possible upwelling mechanisms were analyzed: cross-shore Ekman transport (csET) due to alongshore winds, wind curl (Ekman pumping/suction) due to wind spatial gradients, and dynamic uplift caused by variations in the strength/position of the Caribbean Current. These parameters were derived from satellite wind and altimeter observations. The principal and the mid-year upwelling were driven primarily by csET (78–86%). However, SST had similar or better correlations with the Ekman pumping/suction integrated up to 100 km offshore (WE100) than with csET, possibly due to its influence on the isopycnal depth of the source waters for the coastal upwelling. The mid-year upwelling was not caused by dynamic uplift but it might have been enhanced by the seasonal intensification of the Caribbean Current during that period.

DOI10.3390/jmse6020036
Refereed DesignationRefereed

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