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1 Boutin et al., Avril 2015, SMOS-OCEAN TOSCA SMOS Salinity anomalies Towards the correction of SMOS SSS systematic biases - J. Boutin 1, N. Martin 1, N. Kolodziejczyk 1, O. Hernandez 1, G. Reverdin 1, F. Gaillard 2 1 LOCEAN Paris, France 2 LPO/IFREMER, Brest, France

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2 Boutin et al., Avril 2015, SMOS-OCEAN TOSCA Outline SSS variability at global scale: SMOS and in situ SSS optimal interpolation results Preliminary results of new SMOS SSS ESA v6

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3 Boutin et al., Avril 2015, SMOS-OCEAN TOSCA SMOS Salinity maps CATDS CEC LOCEAN: ESA level 2 SSS (reprocessing version 5) mapped at monthly & 0.25 spatial resolution ; Running average over 100x100km 2 July 2010-June 2014 Ascending + Descending passes available on demand on www.catds.fr (CATDS CEC-LOCEAN product)www.catds.fr

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4 Boutin et al., Avril 2015, SMOS-OCEAN TOSCA Optimal Interpolations of in situ SSS Optimal interpolation of in situ S (ARGO, TAO...) smoothing ~300km ~0.5 resolution at the equator 2005-2014 monthly fields (Myocean product since 2013) Keep only pixels where PCTVAR

6 Boutin et al., Avril 2015, SMOS-OCEAN TOSCA Interannual anomalies Most of SMOS SSS biases are about systematic from one year to the other => build a SMOS monthly SSS climatology (07/2010-06/2014) SMOS SSS anomalies wrt SMOS climatology => interannual variability of SMOS SSS Build ISAS SSS monthly climatology (07/2010- 06/2014) ISAS SSS anomalies wrt ISAS climatology => interannual variability of ISAS SSS

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7 Boutin et al., Avril 2015, SMOS-OCEAN TOSCA Interannual anomalies (see Durand et al. Ocean Dynamics 2013 (tropical Indian Ocean and IOD); Hasson et al. JGR 2014 (La Nia in tropical Pacific Ocean)

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8 Boutin et al., Avril 2015, SMOS-OCEAN TOSCA Further than 800km from the continents 100km-monthly SMOS SSS wrt ISAS SSS and SMOS wrt ISAS SSSanomalies 0.2

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9 Boutin et al., Avril 2015, SMOS-OCEAN TOSCA Further than 1200km from the continents 100km-monthly SMOS SSS wrt ISAS SSS and SMOS wrt ISAS SSSanomalies 0.2 When monthly systematic biases are removed, RMSD (SMOS-ISAS) ~0.2 but ISAS is not the truth (it is smoothed over ~300km) and it is affected by ARGO undersampling...) Doing similar exercise with ship SSS averaged over 0.25 in SPURS region, we found 0.15 (Hernandez et al. 2014)!

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10 Boutin et al., Avril 2015, SMOS-OCEAN TOSCA Biais cotiers: non visibles sur anomalies SSS => biais systematiques => correction? Kolodziejczyk (LOCEAN), Vergely (ACRI-st), Martin (LOCEAN), Marchand (LOCEAN), Boutin (LOCEAN) SMOS (Asc) ISAS SSS 4 year mean All dwells -0.6 0.6 0.

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11 Boutin et al., Avril 2015, SMOS-OCEAN TOSCA Le biais en Tb dpend de la position dans le FOV => biais SSS dpend de la positions across track ~100km gauche du centre ~100km droite du centre

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12 Boutin et al., Avril 2015, SMOS-OCEAN TOSCA Correction simple: on ote un Biais moyen (3ans) /ISAS