Summary of Abstract Submission

Abstract Submission No. IO50-06-0026PresentationPoster

BOREAL SUMMER DIAPYCNAL NUTRIENT FLUX IN THE SEYCHELLES-CHAGOS THERMOCLINE RIDGE

Jenson V George*1, D. Rajasekhar1, N. Anilkumar2, P. Sabu2, Amit sarkar2, Melena A. Soares2

1 NIOT Chennai, India
2 NCAOR Goa, India

ABSTRACT :

Seychelles Chagos Thermocline Ridge (SCTR, 5S - 10S, 50E 75E) in the south western tropical Indian Ocean is a unique area that experiences year round upwelling. The shallow thermocline (< 70 m) and year round upwelling make the SCTR an important region for biological productivity. Previous studies observed surface chlorophyll-a blooms in the south tropical Indian Ocean during boreal summer and suggested that these blooms were associated with the thermocline ridge and is regulated by mixed layer depth (MLD) variability. Microstructure shear profiles collected during the time series observation occupied at 8S 67E from 8 June 2014 to 17 June 2014 provided an estimate of upper layer diapycnal mixing in the SCTR. The diapycnal eddy diffusivity Kz inferred from the shear profiles in the MLD was of the order of 10-2 m2/s and below it ranged between 10-3 m2/s and 10-6 m2/s. Furthermore, the observed Kz indicates that vertical diffusion supplies considerable proportion of the nutrients required for new production in this region