SMOS L2 Ocean Salinity Level 2 Ocean Salinity L2OS planning 2 July 2014 ARGANS & SMOS L2OS ESL 1

SMOS L2 Ocean Salinity L2OS evolution for metrics: AUX_DTBXY To support L1 & L2OS metrics, AUX_DTBXY needs extending to include snapshot statistics for L1c TBs, forward model TBs, and OTT correction TBs: for all polarisations, all 12 FOV sub-zones, & all 3 forward models. To support A3TEC metrics, AUX_DTBXY needs extending to include retrieved TEC and associated data. No changes to algorithm, configuration, or science products = low risk. AUX_DTBXY to increase in size from max ~10Mb to ~13Mb We recommend L2OS v620 is delivered September 2014 and used for reprocessing, to generate AUX_DTBXY as a reference data set for L1 & L2OS metrics, and A3TEC analysis. Summer 2014 delivery (late – due April) will be L1 Metrics Plan (including ADD) based on draft TRUM (Tools Release User Manual) & PPSR. L2OS v620 delivered September 2014 with Tools for L1 Metrics 2

SMOS L2 Ocean Salinity L2OS evolution for metrics: AUX_DTBXY 3 n x geographical regions: region ID, snap start/stop time/ID 3 x forward models 8 x polarisations ott stats deltaTB[xi,eta] std(deltaTB)[xi,eta] count(deltaTB)[xi,eta] flags[xi,eta] for each snapshot in region: ID, lat/long polarisation flags deltaTB (0.3 circle) V612v620 n x geographical regions: region ID, snap start/stop time/ID 3 x forward models 8 x polarisations ott stats deltaTB[xi,eta] std(deltaTB)[xi,eta] count(deltaTB)[xi,eta] flags[xi,eta] for each snapshot in region: ID, lat/long polarisation flags for 12 FOV sub-zones for 3 polarisations L1cTB for 3 forward models forward model TB OTT TB deltaTB measurement count A3TEC stats fov/geo lat/long, lat TEC TEC from L1c & A3, sigma Max snapshots in global region ~1500, in OTT region ~500 Metrics adds < ~3Mb A3TEC adds < ~90Kb

SMOS L2 Ocean Salinity L2OS tuning for reprocessing Reference L2OS data sets: v620 ref (from ESAC rehearsal) – un-tuned configuration: L1c v620 & L2OS v612 ( & – ) v620 run2 (ARGANS) – first tuned configuration: L1c v620 & L2OS v613 ( & – ) L1c v620 configuration update changes border width, RFI thresholds ESL work shows need to revisit L2OS thresholds & filtering, and not to use sun tails flag to filter measurements Reprocessing L2 starts September/October 2014?, end Jan/Feb 2015, followed by L1 & L2 catch-up reprocessing of 2014 data => end April/May 2015? Process L1c (ESAC) May 2011 (ARGANS) in August with revised thresholds New thresholds delivered September 2014 for L2 reprocessing 4

SMOS L2 Ocean Salinity L2OS forward model sensitivity analysis – flat sea model Flat sea SST sensitivity: SST298 minus SST278 Sensitivity to SST is low in XX, but up to 0.1K/degree in YY at high incidence angles Flat sea SSS sensitivity: SSS37 minus SSS33 ~0.6K/psu at low incidence angles ~0.9K/psu at high incidence angles

SMOS L2 Ocean Salinity L2OS forward model sensitivity analysis – wind speed General bias between roughness models of ~±0.5K at 7m/s Model updates : more SMOS data now => better models M1 XX M2 XX M3 XX M1 YY M2 YY M3 YY

SMOS L2 Ocean Salinity L2OS forward model sensitivity analysis Worse case (eg high incidence angle) model sensitivities 7 Flat seaRoughness model 1 Roughness model 2 Roughness model 3 Galactic noise SSS (K / psu) XX 0.03 YY 000 SST (K / degree)0.02 XX 0.1 YY WS (K / m/s)00.4 XX 0.2 YY 0.4 XX 0.15 YY 0.4 XX 0.2 YY < 0.05 Wind direction 7 m/s)0±0.1 XX ±0.15 YY 000 BT (K)SSS (psu) Flat sea Roughness model 1 Roughness model 2 Roughness model SST 17°C, WS 7m/s±2±4 Galactic noise Worse case (eg high incidence angle) model absolute error estimates

SMOS L2 Ocean Salinity L2OS evolution Major improvements in L2OS performance from v550 to v612 from: correction of L1 long term drift (daily OTT) new galactic scattering model TEC retrieval in descending orbits => better Faraday rotation multi-threading Work-plan for identifies tasks for further improvements: minimize flaws in L1 over ocean (biases & flagging) refine forward models improve filtering retrieval methods improve quality assessment & user experience ESL already working on these tasks with promising results (land-sea, filtering) – we expect major improvements in quality of ocean products during next phase. 8

SMOS L2 Ocean Salinity L2OS follow-on ESL contract: work-plan overview 9

SMOS L2 Ocean Salinity L2OS follow-on ESL contract: processor delivery schedule L2OS v630 spring 2015: land-sea correction (WP1.1) improved QC (WP3.1), filtering (WP1.3) update of roughness/foam model 1 (WP 2.2) could be use to re-reprocess L1 v620? L2OS v640 spring 2016: use of new constraints on roughness models (WP2.2) better flat sea model (WP2.1) improved GO galactic glint model (WP2.3) new TEC product (WP3.3) netCDF (WP4.3) L2OS v630 spring 2017: improved (adaptive?) retrieval algorithm(s) (WP3.2) using new/alternative geophysical inputs (WP2.4) mitigation of rain impact (WP2.5) better OTT strategy (WP1.2) comprehensive validation (WP4.1) 10

SMOS L2 Ocean Salinity L2OS follow-on ESL contract: resources (months) 11