|Observed surface thermohaline variability at mesoscale to submesoscale in the Coral Sea, southwest Pacific Ocean. |
Conference: Open Science Conference on Salinity and Freshwater Changes in the Ocean (Hambourg, DE, 2015-10-12)
Ref HAL: hal-01203212_v1
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Several theoretical and numerical studies have recently pointed out thecrucial role of small oceanic structures, with typical scales of 50 km orless, on the ocean eddies (100-300 km), which are associated with themost important part of the total ocean kinetic energy. Indeed, the oceanicflow is driven by nonlinear scale interactions that transfer energy upscale(to the large-scale circulation up to 1,000 km) or downscale (typically lessthan 1m). Knowledge about all these scales is required to explain thedispersion and diffusion of tracers such as sea surface salinity (SSS). Italso echoes the importance of knowing such scales for the calibration andvalidation of the ongoing Aquarius and SMOS satellite missions. In thepresent study, the small-scale features in SSS are examined using in situobservations collected from a thermosalinograph (TSG) during theBifurcation cruise (Sept. 2012) operated in the southwest Pacific Oceanunder the auspices of the SPICE project. The TSG data are replaced in thecontext of the mesoscale eddies and submesoscale ocean dynamics usinga front detection approach based on a Lagrangian technique thatdetermines the Finite-Size Lyapunov Exponents (FSLE). Several examplesof interactions between mesoscale eddies and submesoscale or frontalstructures in SSS will be considered to characterize the stirring and thedispersion of Lagrangian coherent structures. Estimates of the satelliteproducts, as well as considering the biogeochemistry of the surface oceanin the region, will be also presented and discussed.