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L2OS: Product performance summary v550 highlights

L2OS: Product performance summary v550 highlights. The SMOS L2 OS Team . Many presentations made on SSS retrieval issues starting at IOCP Keypoint 1, plus several validation exercises using Argo floats data

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L2OS: Product performance summary v550 highlights

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  1. L2OS: Product performance summary v550 highlights The SMOS L2 OS Team

  2. Many presentations made on SSS retrieval issues starting at IOCP Keypoint 1, plus several validation exercises using Argo floats data Present: First SMOS general reprocessing has provided a coherent data set built with L1OP 5.04 and L2OS 5.50 for product performance analysis SMOS L2 OS Product Performance Status Report issue 2.3, October 2012 (draft under improvement): Status of main SSS retrieval problems Analysis of one year of SMOS salinity, 2011 User Data Product performance review Status tables for UDP fields: grid point data, salinity, flags and quality descriptors SMOS L2OS performance 2

  3. SMOS L2OS performance • L2OS operational processor history • reprocessing 2010-11 • v550 main change: double OTT (asc/desc), updated monthly (bi-weekly and centeredfor reprocessing) • Other minor 500 & 550 modifications (several flags/filtering improvements, bugs fixed, new LUTs for roughness,...) • Strong impact of L1 modifications

  4. Issues still degrading SMOS SSS retrieval. Different degrees of improvement with the new L1 & L2 processors versions: Land contamination RFI Unrealistic drifts: long/short TB drifts, geophysical Sun tails Galactic noise modelling Roughness effects Auxiliary data quality: wind vector, TEC, ... 3, 4, 5 impacting the spatial bias correction (OTT technique) SMOS OS retrieval problems Paul (+ Nicolas) Paul, Joe (+Jérôme) Jacqueline Joe Paul 4

  5. L1 346 (withbugcorrected) + L2 317 - climatology L1 504 + L2 550 - climatology RFI RFI Land contamination Expectedimpact of Gibbs No flagfiltering has beenapplied, to keepcontaminated data byC. Gabarró, ICM/SMOS-BEC 5

  6. L1 346 + L2 317 (withbugcorrected) - climatology L1 504 + L2 317 - climatology L2 550 - L2 317 6

  7. Asc-desc monthly average March 2011 reprocessed July 2011 reprocessed 7

  8. Asc-desc monthly average September 2011 reprocessed November 2011 reprocessed 8

  9. Roughnesseffects Pre-launch roughness models and fitted to SMOS data • Wind induced Tb at θ=32.5°from 3 models and SMOS data • Pre-launch: bad fit to ECMW wind speed sensitivity • Tuned after analysis of SMOS data: much better agreement • Clear non-linear behaviour with wind speed Pre Post V-Pol H-Pol V-Pol H-Pol by S. Guimbard, ICM/SMOS-BEC

  10. Roughnesseffects Differences between 3 roughness models: Highly reduced after fitting to SMOS data (SSS2 is now also semi-empiric) Yearly statistics of L3 1º x 1º monthly maps (filtering out wind >12 m/s): Global S. Pacific N. Pacific 60N-60S OTT region 45N-60N • bias STD bias STD bias STD • SSS1-SSS2 0.01 -0.02 0.02 -0.01 -0.06 0.01 • SSS1-SSS3 0.02 -0.03 0.03 0.00 -0.09 0.00 • SSS2-SSS3 0.01 -0.01 0.01 0.01 -0.03 -0.01 • Variability in the SSS field due to the different roughness correction is lower than requirements (0.1 for 100 km 30 days averages)

  11. Roughnesseffects Retrieved SSS usingthethreeroughnessmodelsimplemented in v550

  12. Roughnesseffects AfterfilteringbyDg_quality_SSSx Ascendingorbiton 19 October 2012

  13. Product performance review Objective: to report performance of the fields in the User Data Product • Analysis of SSS accuracy • Analysis of quality descriptors (flags and counters) • Summary in status tables • No analysis for Acard (no in situ data for validation) • No analysis for non-retrieved parameters (SST, WS) • No analysis for by-products (modelled TBx,y,h,v at 42.5º)

  14. Global SSS maps 10-days/1o averaged SSS 3 -12 August 2011 Zonal average SMOS-Argo Old processors +0.2 - 0.2 New processors L1 v3.46 v5.04 L2OS v3.17 v5.50 by J. Martínez, ICM/SMOS-BEC 14

  15. SSS accuracy: firstapproach Zero order accuracy: comparison to climatology 2011 yearly statistics of 9-days L3 maps in 10ºx10º or 2ºx2º regions of contrasted conditions, different for ascending/descending • range usually OK • anomaly within few 0.1s • important asc/descdiffer. • exception: RFI areas, low SST, high variability

  16. SSS accuracy: in situ validation Comparison SMOS-Argo: Proxy for absolute accuracy (with care due to Argo not samplig SSS). Only data set available for global analysis. More precise local comparisons possible (moored buoys, surface drifters) Diagnostic sites defined in Product Performance Evaluation Plan • Interestingoceansituations • In situ samplingprograms • Expectedproblems

  17. SSS accuracy: in situ validation • L3 binned products, filtering poor L2 grid points, wind <12 m/s, centre of swath, 2011 yearly statistics for ascending/descending/both orbits Different analysis methodologies: • SMOS data selection (filtering by flags) • Argo data selection and interpolation to (sub)surface values • Match-up criteria • Statistical approach • BEC: 10-d/2º, monthly/1º maps, SSS3, 400 km, Argo 7.5m, box averaging • LOCEAN: 50 km/15-d, 100 km/15-d collocations, SSS1 weighted, 300 km

  18. SSS accuracy: in situ validation 0.04-0.15 ±0.5-0.6 ±0.2-0.3 ±up to 1.3 BEC: 1º/30-d LOCEAN: 50 km/15-d

  19. Validation in specificregions Monthly 1º maps: regional comparisontoArgo SMOS ascendingorbits ±300 km 3-12 m/s wind Bias - 0.04 0.02 - 0.07 - 0.15 STD0.25 0.38 0.48 0.31 SSS September 2011 SMOS (up), Argo (bottom) by J. Boutin et al., LOCEAN 19

  20. Interannual variability SMOS : 2011-2010 Big spatial SSS 2011-2010 structures are qualitatively consistent between SMOS and ARGO SMOS provides higher spatial resolution (+coastal and RFI errors!) ARGO : 2011-2010 by S. Guimbard, ICM/SMOS-BEC 20

  21. SSS status summarytable • Based on regional computations (yearly averages)

  22. Flags and descriptors • Reported status for: • 25 control flags • 22 scienceflags • 19 productconfidencedescriptors • Fields name, definition, dependencies, thresholds, status, usability, comments example: status: OK = implementationchecked comments: can includeevaluation of flagusefulness in terms of its impact on filtering data to improve the quality of SSS maps. And eventually conclusions on the thresholds values.

  23. Analysis of reprocessed 2011 data set Main issues continue to be the same Linked to calibration, image reconstruction and modelling of geophysical variability L2OS team working on possible corrections First version of Product Performance Status Report well advanced: shaping information for users SMOS SSS globally not reaching mission requirements, regionally approaching them Conclusions 23

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