SMOS – in situ comparisons J. Boutin*, N. Martin*, O. Hernandez*, N. Reul , G. Reverdin* *LOCEAN,  IFREMER

Outline SMOS-ARGO in 2012 SPURS-STRASSE comparisons Gulf stream region

-SSS between 25 & 40 psu for latitudes between 30S & 30°N (Hence SSS=-999 are discarded) -SSS between 30 & 40 psu for latitudes outside 30°S-30N (Hence SSS=-999 are discarded) -Dg_af_fov >=130 In addition we test the following flags: "control_flag_set=CTRL_SEL_GP;CTRL_ECMWF, "control_flag_clear=CTRL_NUM_MEAS_MIN;CTRL_NUM_MEAS_LOW;CTRL_MANY_OUTLIERS;CTRL_SUNGLINT;CTRL_MOO NGLINT;CTRL_REACH_MAXITER;CTRL_MARQ;CTRL_CHI2_P;CTRL_CHI2;CTRL_SUSPECT_RFI", "science_flag_set=SC_LOW_WIND;SC_LAND_SEA_COAST1", "science_flag_clear=SC_ICE;SC_SUSPECT_ICE" Some of these flags have been kept by continuity with previous versions. With respect to your comments: CTRL_SEL_GP is not used anymore => to be removed CTRL_CHI2 is redundant with CTRL_CHI2_P (in case of more than 30 meas.) =>to be removed CTRL_NUM_MEAS_MIN;CTRL_NUM_MEAS_LOW : useless if Dg_af_fov >=130 is tested (but may be useful if we would decide different levels of global flags, e.g., Good, probably good, probably bad, bad) SC_SUSPECT_ICE: taken by precaution; we also strongly recommend in v600 to define SC_ICE with Tg_ice_concentration=0% instead of 30% CTRL_SIGMA: we don't use it because we always use sigma to weight our averages We don't use the combined flags poor_geophysical flag and fg_ctrl_poor_retrieval, as we prefer to get original flags (in case definitions of combined flags change). Range of SSS: although we agree that SSS could be lower than 25 in the tropics, there are also a lot of RFIs not well filtered that can lead to low SSS so we prefer to be safe and I would recommend for a 'Good' flag to keep these ranges.

SPURS area O. Hernandez, J. Boutin, G. Reverdin, N. Martin

Large scale bias between SMOS & AQUARIUS averaged over SPURS area We first correct for a mean bias between SMOS & WOA or AQUARIUS & WOA

Comparisons SMOS-Toucan & Colibri (+/-9jours, +/-50km) Mean and standard deviation of SSS SMOS – SSS TSG for each campaign (Colibri and Toucan). Correction of bias B1 is applied. In green: colocalisations in October 2011 Mean negative bias because WOA SSS often lower than in situ SSS

All data R2 =0.78 n = mean = std = 0.2 median = RMSE = 0.21 Error < 0.4 PSS-78 R2 =0.81 n = mean = std = 0.18 median = RMSE = 0.19

Gulf Stream area J. Boutin, N. Reul, G. Reverdin Results obtained with CATDS CEC (after RFI per angle classes filtering, 5°x5° bias correction)

L2 OS in Gulf Stream region 26 transects of Oleander ship (validated by G. Reverdin): Asc+Desc, Des, Asc Better consistency between SMOS Asc & SMOS Desc than with ship data  Error on SSSA or SSSD~0.6  but error SSSsmos A+D wrt Oleander = 1.2 WHY???