1 / 14

The salinity signal of the shelf-deep ocean exchange in the SWA: Satellite observations

The salinity signal of the shelf-deep ocean exchange in the SWA: Satellite observations. 1 Instituto Nacional de Investigacion y Desarrollo Pesquero, Argentina

vera-manning
Télécharger la présentation

The salinity signal of the shelf-deep ocean exchange in the SWA: Satellite observations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Thesalinitysignal of theshelf-deepoceanexchange in the SWA: Satelliteobservations 1 Instituto Nacional de Investigacion y Desarrollo Pesquero, Argentina 2 Servicio de Hidrografıa Naval and Departamento de Ciencias de la Atmosfera y los Oceanos, Universidad de Buenos Aires and UMI/IFAECI, CONICET, Argentina 3 College of Earth, Ocean and Atmospheric Sciences, Oregon State, USA 4 RemoteSensingSolutions, Inc., Pasadena, California 5oUniversity of California, Los Angeles, California, USA 6 Universidad Nacional del Sur and Instituto Argentino de Oceanografıa, Argentina 7 Departamento de Ciencias de la Atmosfera y los Oceanos, Universidad de Buenos Aires, and UMI/IFAECI, CONICET, Argentina Raul A. Guerrero1, Alberto R. Piola2,7, Harold Fenco1, Ricardo P. Matano3, Vincent Combes3, Yi Chao4,5, Corinne James3, Elbio D. Palma6, Martin Saraceno7, and P. Ted Strub3 9th Aquarius/SAC-D Sc. Meeting Seattle, USA Nov. 2014

  2. Mean SSS-Aquarius L3 (v2.0) -SSS from Aquarius shows the main ocean-basin features of the South Atlantic, already proven since the early results of the mission.

  3. Stand.Deviation of SSS-Aquarius The export of shelf waters to the deep ocean near 35ºS creates the largest signal of SSS variability in the SA (south of the tropics).

  4. SWA – Shelf / Deep-Ocean - SSSaq SWA – Shelf / Deep-Ocean – SSSin-situ PPW Plata PlumeWater SASW Subant. ShelfWater STSW Subtrop. ShelfWater Deepocean (>200m) upper 50m water

  5. time scales weeks Spatialscales  100 km MESO-SCALE processes  Remote SST  Remote SSH  Remote SSS • Kernel density estimator (K) • Gaussian function (k(z)) • Bandwidth = 0.75 (h) • L2 – weekly • SSS range: 20  38 • Grid size: 0.5 x 0..5 • Search Radius = 1° x 1° • Smoothing Factor = 0.001 A ChallengeforAquarius??? Griddingtechnique: Local polynomial (Lilly and lagerloef (2008) Individual polynomial adjustments every search radius; optimizing in its environment for a better representation of the local variation

  6. 3 WeeksWeightedMovingAverange (3WeMA) 50% (WEEK 2) 25% (WEEK 1) 25% (WEEK 3) 20-60-20% 15-70-15% In either case SEAM TO BE IMPROVEMENTS in the error levels

  7. New L3 weeklyfor Dec11-2011 Aquarius (a) and SMOS (b) • LSW  deepocean • Aquarius & SMOS • Cyclonic (C2; C3) • Anti-cyclinicrings (A1) • Validatedby: • Surfacecurr. (OSCAR) • SST (Modis) • Chla (modis)

  8. Time serie 27Nov-2011 / 1Jan-2012Evolution of a Low SSS intrusionintothedeepoceanand tracking of warn-salty and cold-freshrings

  9. SSS variabilityalongtracks(crossshelf break) Seasonal • Fresher • Spring-Summer • Salty • autumn and winter Intra-seasonal LSW detrainmentsintothedeepocean

  10. Time series of SSSaq at central track • SSSAq and SMOS • Outershelf (point 3) • Slope (Point 4) Wind stress (Area “d”) c) ASCAT alongshelf (obs and 2008-13 daily mean). d) ASCAT WS anomaly (along.S.) e) Rio de la Plata discharge Seasonal SSS: Fresher Spring and summer SaltierAutumn and winter SSS < 33.5 crossingthe 200m - Mostlyspring-summer time - WhenWind stress reverse to SE - No obvios influencefromRdPdisch

  11. Detrainmentevents (SSS<33.5 crossing 200m)

  12. Summer mean SSSaqanomaly and dynamictopographyanomaly LSW alongthe BMC Obs: Gordon 1989 Provost et al. 1996 Modelling: Palma et al. 2008 SSSaq and Smos LSW derives fromRdlP Drivenbythe BMC and occursmostly in late spring and summer. Location~ 37°S  In agremmentwithnumericalsimulations (Matano et al., 2014)

  13. Winter SSS fields and anomalies (Smos and Aquarius) • Weakerdetrainments in SSS: • Fewerevents • Underwindreversalcond. • NO RdlPdischargeinflu. Location: 27°S  35°Salso in agremmentwithnumericalsimulations(Matano et al., 2014) Still intense LowSalinity (< -.5) intothedeepocean (in contrasttoBrazilWater) resulting in a warmvariety of ShelfWaters(Gordon 1989; Piola et al., 2008)

  14. Summary and Conclusions • Aquarius and SMOS SSS capture the detrainment of shelf waters into the deep ocean • The export of shelf waters near the RdlP causes the strongest salinity signal throughout the South Atlantic (south of 10°S) • Thedetrainments of low-salinity waters present a strong seasonal signal which is associated with the alongshore wind stress variabilityovertheshelf: Summer 36-37°S; Winter 27-35°S • The low-salinity waters cause an extensive negative salinity anomaly whose core follows the path of the BMC • The general agreement with the numerical simulations and in situ observations indicate an outstanding overall performance of the satellite-based salinity sensors

More Related