Comparison between high resolution altimetric products and in situ observations to guide an oceanographic cruise (OUTPACE).
Résumé
The inter-disciplinary OUTPACE project conducted an oceanographic cruise in the South-West
Pacific in February-March 2015 in order to study the biogeochemical fluxes in this under-sampled
region. During the cruise multiple near-real-time satellite-derived products provided by AVISO and
CLS were used during the cruise to generate daily maps of SST, surface chlorophyll a concentration
and Lagrangian diagnostics allowing to identify fronts, eddies and filaments. This allowed to guide
successfully the in situ sampling strategy. This adaptive strategy reveals to be a success as 3
contrasted region were sampled during the cruise. For post-cruise analyses we use specifically
designed high resolution regional altimetric products produced by CLS (with support from CNES).
Preliminary results show that the addition of the Ekman component considerably increase the
agreement between the satellite product and the trajectories of SVP (Surface Velocity Program)
floats. At submesoscale, Lagrangian diagnostics such as Finite Size Lyapunov exponents, calculated
with altimatric products, allow to detect physical fronts which generally match with in-situ surface
tracer gradients.