Overview of SMOS level 2 ocean salinity processing and first results<br />1<br />J. Font, J. Boutin, N. Reul, P. Spurgeon,...
SMOS SSS mission requirements<br />Themultiangularmeasurements of anypointontheEarth’ssurfaceprovidedbythe SMOS interferom...
3<br />SSS and Tb values<br />Polarisation and viewing geometry provide a higher range of Tb values<br />Sensitivity of Tb...
SMOS Sea Surface Salinity retrieval<br />4<br />Atmosphere<br />Ocean<br />Retrieval from brightness temperature through a...
5<br />SMOS SSS retrieval expectations<br />L2 accuracy estimated during algorithm validation<br />	- 1-2 psu range <br />...
Bias in the comparison of measured and modeled Tb<br />Spatialpatternpersistentalong and in differentorbits<br />Similar u...
8<br />Firstsalinitymap<br />by J. Tenerelli, CLS, Brest, 10 Feb 2010 <br /><ul><li> Comparing SSS map generated with 3 da...
 No data averaging
 Degraded results in FOV borders, near coast, and in areas of strong wind</li></li></ul><li>Amazon plume detected by SMOS<...
10<br />Mainproblems in SSS retrieval<br /><ul><li>Impact of landon Tb biaspatterns</li></ul>by J. Tenerelli & N. Reul<br />
Mainproblems in SSS retrieval<br /><ul><li>Contaminationfrom radio frequencyinterferences (RFI)</li></ul>TY browse<br />SS...
12<br />Latitudinal SSS gradients<br />S-N SSS anomaly in the Pacific: comparing SMOS and ARGO<br />0.1 degree bin in lati...
Combiningseveral SMOS orbits<br />Weekly global salinitymap, July2010: weightedaveraging + discardingflagged data<br />byM...
ComparingdifferentOTTs<br />14<br />WARNING: New Flat Target TransformationJuly 2010<br />SSS anomaly (misfit between retr...
Checkingprocessingoptions<br />15<br />Sea surfacesalinityfrom ten days of combinedorbits in theeasternPacificusingonlythe...
Analysis of SMOS AF-FOV data<br />a square of 0.25 in instrument coordinate,<br />about 600 * 600 km,<br />(smaller biases...
SMOS<br /><ul><li>   Argo</li></ul>Multi-orbit SMOS vs. in situ<br />5-day mean SSS onboard TAO (tropical atmosphere ocean...
SMOS and in situ SSS anomalies<br />SMOS - WOA05<br />SSS of SMOS, WOA05 and ARGO/ISAS averaged into 0.5° bin in latitude<...
Validation of SMOS L2 products<br />Preliminary global validation: <br />March 2010: comparison of SMOS data compositewith...
Status of SMOS SSS retrieval<br />Ongoingstudieson:<br />Bias removal techniques<br />Land and RFI contaminationmitigation...
21 / 10<br />Dr. Gerasimos Korres, GRE<br />Dr. Nicolas Reul, FRA<br />Dr. Juha Kainulainen,  <br />FIN<br />Dr. George Zo...
 Define standardized data processing protocols
Upcoming SlideShare
Loading in …5
×

TH2.L10.2: OVERVIEW OF SMOS LEVEL 2 OCEAN SALINITY PROCESSING AND FIRST RESULTS

572 views
508 views

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
572
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
8
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

TH2.L10.2: OVERVIEW OF SMOS LEVEL 2 OCEAN SALINITY PROCESSING AND FIRST RESULTS

  1. 1. Overview of SMOS level 2 ocean salinity processing and first results<br />1<br />J. Font, J. Boutin, N. Reul, P. Spurgeon, J. Ballabrera, A. Chuprin, C. Gabarró, J. Gourrion, C. Hénocq, S. Lavender, N. Martin, J. Martínez, M. McCulloch, I. Meirold-Mautner, F. Petitcolin, M. Portabella, R. Sabia, M. Talone, J. Tenerelli, A. Turiel, J.L. Vergely, P. Waldteufel, X. Yin, S. Zine, S. Delwart(The SMOS L2 OS Team)ICM-CSIC/SMOS-BEC Barcelona, LOCEAN Paris, IFREMER Brest,ARGANS Plymouth, ACRI-STSophie-Antipolis, ESA-ESTECNoordwijk<br />jfont@icm.csic.es<br />
  2. 2. SMOS SSS mission requirements<br />Themultiangularmeasurements of anypointontheEarth’ssurfaceprovidedbythe SMOS interferometricradiometer MIRAS at eachsatelliteoverpass are aimed at: <br />Determining sea surfacesalinitywithanaccuracy of the<br />order of 0.1 practicalsalinityunits, 100 – 200 km spatialresolution and 10 – 30 days temporal resolution<br />Usefulforlargescale<br />oceanographic and climate<br />studies<br />2<br />(© P. Carril for ESA)<br />
  3. 3. 3<br />SSS and Tb values<br />Polarisation and viewing geometry provide a higher range of Tb values<br />Sensitivity of Tb to SSS is small especially at low temperatures<br />Retrieving salinity with SMOS is a challenge that requires very good performance of the instrument and a very demanding data processing: new models and algorithms being implemented and now improved<br />
  4. 4. SMOS Sea Surface Salinity retrieval<br />4<br />Atmosphere<br />Ocean<br />Retrieval from brightness temperature through a convergence loop<br />Comparing model (guessed SSS) with measurements at all incidence angles<br />Sea surface emissivity model (top 1 cm) including roughness effects<br />Other contributions from external sources and atmospheric effects<br />Need for auxiliary data to describe environmental conditions<br />Tb,p = Tb,pflat(θ, SST, SSS) + Tb,p rough (θ, Ф, wind waves, swell, other wave characteristics, foam coverage, foam emissivity, rain)<br />
  5. 5. 5<br />SMOS SSS retrieval expectations<br />L2 accuracy estimated during algorithm validation<br /> - 1-2 psu range <br /> - function of distance to track<br /> - depending on environmental variables<br /><ul><li>Mission requirements to be reachable through spatio-temporal averaging (level 3)</li></li></ul><li>The SMOS L2 OS processor<br />6<br />Developed by the SMOS L2 OS team and implemented by Argans Ltd., UK<br />Retrieved SSS along a SMOS ascending orbit in the Pacific Ocean. <br />Unfiltered (left) and filtered (right, removing flagged data) values <br />
  6. 6. Bias in the comparison of measured and modeled Tb<br />Spatialpatternpersistentalong and in differentorbits<br />Similar usingdifferentoceanemissivitymodels: relatedtoinstrument and imagereconstructionimperfections<br />Removaltechniquesbeingtested: theOcean TargetTransformation (OTT, mean residual biasoverhomogeneousoceanareas)<br />7<br />Mainproblems in SSS retrieval<br />(seetalkby M. Talone, Friday)<br />
  7. 7. 8<br />Firstsalinitymap<br />by J. Tenerelli, CLS, Brest, 10 Feb 2010 <br /><ul><li> Comparing SSS map generated with 3 days of SMOS data (ascending orbits 29-31 Jan 2010, using OTT derived in December) and WOA climatology for January (simplified retrieval, not SMOS L2 processor)
  8. 8. No data averaging
  9. 9. Degraded results in FOV borders, near coast, and in areas of strong wind</li></li></ul><li>Amazon plume detected by SMOS<br />SMOS descendingorbits, March 2010<br />In situ Marchclimatology (1977-2002) @ 1°x1° (G. Reverdin, LOCEAN)<br />9<br />by N. Reul, IFREMER, Brest<br />
  10. 10. 10<br />Mainproblems in SSS retrieval<br /><ul><li>Impact of landon Tb biaspatterns</li></ul>by J. Tenerelli & N. Reul<br />
  11. 11. Mainproblems in SSS retrieval<br /><ul><li>Contaminationfrom radio frequencyinterferences (RFI)</li></ul>TY browse<br />SSS descending10-25 July<br />11<br />
  12. 12. 12<br />Latitudinal SSS gradients<br />S-N SSS anomaly in the Pacific: comparing SMOS and ARGO<br />0.1 degree bin in latitude, all grids <br />across swath<br />- 1 SMOS half orbit on 11 December 2009<br />- World Ocean Atlas 2005 SSS climatology<br />- Monthly ISAS analysis of ARGO surface fields in December 2009, Gaillard, LPO, 2010<br />by J. Boutin & X. Yin, LOCEAN, Paris<br />
  13. 13. Combiningseveral SMOS orbits<br />Weekly global salinitymap, July2010: weightedaveraging + discardingflagged data<br />byM. Talone, SMOS-BEC, Barcelona<br />(seetalkby R. Sabia,<br />thisafternoon)<br />13<br />
  14. 14. ComparingdifferentOTTs<br />14<br />WARNING: New Flat Target TransformationJuly 2010<br />SSS anomaly (misfit between retrieved and monthly climatology) by using a single half-orbit OTT<br />SSS anomaly by using a <br />model-independent bias<br />mitigation technique<br />by J. Gourrion, SMOS-BEC, Barcelona<br />(seetalkby M. Talone, Friday)<br />
  15. 15. Checkingprocessingoptions<br />15<br />Sea surfacesalinityfrom ten days of combinedorbits in theeasternPacificusingonlythe Alias-Free Field-of-View and thethreeroughnessmodels<br />by A. Chuprin, Argans Ltd., Plymouth<br />
  16. 16. Analysis of SMOS AF-FOV data<br />a square of 0.25 in instrument coordinate,<br />about 600 * 600 km,<br />(smaller biases and noise) <br />5 day, SMOS SSS (17-21March, 2010) ascending orbits<br />Only Tb measurements in a square in center of FOV, cleanest Tb<br />by J. Boutin & X. Yin, LOCEAN, Paris<br />16<br />
  17. 17. SMOS<br /><ul><li> Argo</li></ul>Multi-orbit SMOS vs. in situ<br />5-day mean SSS onboard TAO (tropical atmosphere ocean project) moorings (16 -20 March, 2010)<br />Monthly ISAS analysis of ARGO surface fields of March, 2010 <br />( F. Gaillard)<br />5-day SMOS SSS: covers areas not sampled by Argo in one month<br />17<br />
  18. 18. SMOS and in situ SSS anomalies<br />SMOS - WOA05<br />SSS of SMOS, WOA05 and ARGO/ISAS averaged into 0.5° bin in latitude<br />Possible reasons for discrepancy<br />SMOS sees 5-day mean SSS at 1 cm depth, while WOA and ISAS SSS are monthly average<br />Is bias removal strategy robust enough? <br />18<br />
  19. 19. Validation of SMOS L2 products<br />Preliminary global validation: <br />March 2010: comparison of SMOS data compositewith 7296 in situ salinityvalues (Argofloats)<br />~0.5 psu accuracy @ 0.25° resolution<br />by N. Reul, IFREMER, Brest<br />19<br />Validationusing L3, J. Ballabrera, SMOS-BEC, Barcelona (seetalkby J. Gourrion<br />thisafternoon)<br />
  20. 20. Status of SMOS SSS retrieval<br />Ongoingstudieson:<br />Bias removal techniques<br />Land and RFI contaminationmitigation<br />Forward modelsimprovement<br />Salinitymapsgeneration and validation<br />July 2010: data to Cal/Val teams<br />20<br />Seedetailedpresentations:<br />TH3.L02.1 Sabia et al. SMOS measurements preliminary validation against modeled brightness temperatures and external-source salinity data<br />TH3.L02.2 Gourrion et al. Preliminary validation of SMOS products (levels 3 and 4)<br />FR2.L10.5 Talone et al. SMOS brightness temperatures validation: first results after the commissioning phase<br />
  21. 21. 21 / 10<br />Dr. Gerasimos Korres, GRE<br />Dr. Nicolas Reul, FRA<br />Dr. Juha Kainulainen, <br />FIN<br />Dr. George Zodiatis, CYP<br />Prof. Johnny Johannessen, NOR<br />Prof. Aldo Drago, MAL<br />Dr. Pierre-Marie Poulain, ITA<br />Dr. Brian Ward, IRE<br />Dr. Christine Gommenginger, ENG<br />Dr. Roberto Sabia, SPA<br />Dr. Alexander Ostrovskii, <br />RUS<br />Prof. Ana Martins, POR<br />COST Action network<br />SMOS-MODE<br />SMOS Mission Oceanographic Data Exploitation<br />Coordinate pan-European teams to define common protocols to produce high-level salinity maps and related products, and broaden expertise in their use for operational applications.<br />Benefits<br /><ul><li>Unify disperse knowledge and efforts
  22. 22. Define standardized data processing protocols
  23. 23. Address problems with high societal/industrial impacts</li></ul>Schedule<br /><ul><li> Sep.09: Preliminary proposal
  24. 24. Nov.09: Selected for full-proposal
  25. 25. Mar.10: Selected for hearing session
  26. 26. Jun.10: Approved!</li></li></ul><li>22<br />Thank you for your attention!<br />

×