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ASAR Calibration Review Wave Mode: Achievements & Planning

ASAR Calibration Review Wave Mode: Achievements & Planning (With contributions from the ASAR Wave Cal/Val Team). Project time-line Milestones Quick review: The ASAR Wave Cal/Val Team Team Achievements: Status summary. Project Timeline.

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ASAR Calibration Review Wave Mode: Achievements & Planning

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  1. ASAR Calibration Review Wave Mode: Achievements & Planning (With contributions from the ASAR Wave Cal/Val Team) • Project time-line • Milestones • Quick review: The ASAR Wave Cal/Val Team • Team Achievements: • Status summary

  2. Project Timeline

  3. Central Wave Team database & distribution point (FTP) Buoy data collected systematically ASAR Wave collocated with buoy data & WAM (ECMWF) Product containing ASAR Wave WVS & WVW and buoys data in HDF format Available from Sept 2001 Réception et mise au format générique BD Bouées … Espace FTP des données bouées FTP/ WWW Co-localisation Produit Spécifique ASAR WAVE MODE Ifremer Collocation System

  4. “Collecting” buoy networks. All of the Wave Team 15 March 2002. Final list of buoys in cal/Val plan NOAA – Meds buoys in collocation system To come: Norway Spain UK-Ireland France India S. Africa Buoys

  5. Wave Team Webpage • Live: 22 July 2001 • Meetings page • Documents • Data download • Buoy information • Ifremer collocation system

  6. Data Distributed • April 2001: Simulated Level 1 data using ERS-2 • June 2001: Simulated Level 2 data using ERS-2 • June 2002: ASAR Level 1 & 2 available • 11 tracks, IS2, VV • WAM & 2 buoys collocated • Aug 2002: 6 collocated L1 & L2 • NORUT & Ifremer distribution

  7. NORUT / Ifremer - algorithm & product development. ARGOSS - algorithm comparison. with PIs -, DLR, GKSS. Ifremer - collocation system, wave data & buoys CETP - airborne flight campaign. CNR, Bologna - validation in the Mediterranean. Meteo Centres: ECMWF, Meteo France, UK Met The ASAR Wave Cal/Val Team

  8. ESA “V” ARGOSS SPRA algorithm showed: ESA algorithm: Good performance up to 8 m/s wind speed, not biased ESA algorithm: Saturation above 8 m/s ESA algorithm: remarkable agreement for mean wave period with WAM model data ARGOSS Algorithm Validation : Pre-Launch • ARGOSS 1st Independent Assessment of ESA Level 1b algorithm • Algorithm Comparing the ESA, ARGOSS (SPRA) and the “old” ERS-SAR algorithms with WAM model data.

  9. VALPARESO: VALidation with Polarimetric Airborne Radar of the ENVISAT SAR over the Ocean (IFREMER, Météo-Fr & CETMEF) Preparation of the experiment: Flying 19 Oct 21- Nov 2002 (20 flights planned) Radar: STORM on MERLIN-IV: new polarimetric system (5.35 GHz) Incidence: 5 to 35 ° Main objectives: 1. Validation of MTF used by ESA for VV IS2 Wave Mode 2. Development of inversion algorithm for other ASAR configurations (polarization, incidence) using collocated: ASAR SLC Images (Image mode) STORM data (airborne Real-Aperture Radar) providing directional spectra of ocean waves In-situ data from directional system (BEAIII) Wave prediction model data (WAM and VAG) Team Progress: CETP

  10. Secondary objectives: Study of polarimetric radar observations over the ocean using collocated: ASAR SLC Images (Image in HH or VV and Alternating Polarization Modes) STORM data providing complete polarimetric signature of ocean surface + directional spectra of waves + wind vector from a wind-scatterometer mode) In situ data (wind, waves) from a directional system (BEAIII) Wave prediction model data, WAM & VAG Other Study (with IFREMER) Study on the Influence of the tilt MTF on inversed wave spectrum using : Level1b + Level2 inversion algorithm WAM-2D spectra, Team Progress: CETP-2

  11. Objectives: Measurement of 2d wave spectra from ASAR wave L-1 for model assimilation. (With the UK Met Office and the ECMWF) To utilise the new phase information in complex ASAR images, e.g. for detection of extreme waves or wind field retrieval. Milestones: 3 weeks ERS-2 data reprocessed to ASAR L-1 using DLR BSAR processor. 1st global analysis of cross spectra method. Wave directions from cross spectra in good agreement with WAM Development of a technique to estimate 2d sea surface elevation fields, to be used to derive of extreme wave statistics A quasi-linear inversion scheme (no prior information) applied to first Envisat data. Results encouraging, e.g. smooth and consistent Team Progress: DLR

  12. ASAR is an attractive data source that can serve 2 key aims: The validation and verification of the available theories and models Assimilation in operational model to enhance "nowcast" and to produce better forecasts (ECMWF mission as an operational centre). Milestones with ASAR spectra available so far: System set-up to monitor and validate the wave mode products (1b and 2), inversion software modified to handle level 1b System developed for assimilation of SAR spectra into ECMWF wave model using ERS-2 data. Results are positive and encouraging. Ready for assimilation of the ASAR spectra when sufficient coverage. Providing WAM data used for validation Success criteria: do ASAR Wave data improve forecast models ? Team Progress: ECMWF

  13. UK Met Office New link to allow transfer of ASAR Wave 1b data to UK Met Office. This might also be used for level 2 products. The Met Office plan to perform a retrieval validation exercise comparing the DLR algorithm and the ESL Level 2 algorithm; used with both ERS and ASAR data. CNR-Bologna Validation of the wave spectrum retrieval for ASAR in the Mediterranean Sea Network of buoys of the Italian National Hydrographic Service Team Progress: UK Met & CNR

  14. Providing operational wave model spectra for the VALPARESO Testing assimilation scheme using ASAR spectra WAM & VAG to be compared with buoys, ASAR & STORM Plan (to end 2002) Evaluate and improve assimilation scheme using ASAR data ASAR data to be compared to WAM obtained by hindcasting 2002-2003 Validate ASAR data and to test the impact of the assimilation of the data on the wave forecast over a long period (a few months) Implementation of the assimilation scheme in the operational wave model and the impact will be tested again. 2003- If results are satisfactory, assimilation of ASAR data together with Jason and Envisat altimeter data should become operational Team Progress: Meteo France

  15. 4 3.5 3 2.5 2 1.5 1 0.5 0 10 20 30 40 50 60 70 Team Progress: Meteo France Impact of the assimilation on the SWH alongtrack Impact of the assimilation on the SWH field Assimilation of level 2 ASAR data in WAM wave model

  16. Team Progress: Meteo France The wind sea in the WAM 1st guess not seen by the ASAR but is built by the assimilation scheme (ASSI) Swell energy slightly reduced according to ASAR Some problems when ASAR spectrum is too complex Work in progress

  17. Preliminary results (limited data): Encouraging Off-line processing: For special requests (ERS-ASAR) Buoys: In the Cal/Val acquisition plan Collocation system: Working ARGOSS: Ready to begin algorithm comparison Meteo centres: Systems adapted to input Wave data Meteo centres: Ready to assimilate Wave into models Wave Status Summary

  18. Saleh AbdallaECMWF, Tel. +44-118-949 97 03 e-mail: abdalla@ecmwf.int Jean Raymond BidlotECMWFTel +44-118-9499708e-mail: jean.bidlot@ecmwf.intBertrand ChapronIFREMERBertrand.Chapron@ifremer.fr Josep ClosaESA-ESRINTel: +39 06 941 80 573Email: josep.closa@esa.intYves-Louis DesnosESA-ESRINTel: +39 06 941 80 606Email: yves-louis.desnos@esa.intJim GunsonUK Met Office.Tel: +44 (0)1344 854885E-mail: jim.gunson@metoffice.com Giacomo De Carolis CNR-ITIS c/o CGS-ASI tel +39 0835 377282 Email decarolis@itis.mt.cnr.it Cees de Valk ARGOSS tel  +31 527 242299 email valk@argoss.nl Daniele Hauser CETP Tel: ++ 33 1 39 25 48 52 E-Mail: daniele.HAUSER@cetp.ipsl.fr Jochen Horstmann GKSS Phone: +49 (4152) 87-1567 Email: Jochen.Horstmann@gkss.de Harald Johnsen NORUT tel: +47 77 62 94 22 email: harald.johnsen@itek.norut.no Jean-Michel Lefevre Meteo France tel;work:+33 5 61 07 82 95 email: jean-michel.lefevre@meteo.fr Team Members: Contact Details

  19. Dr. Susanne Lehner DLR Tel.  : +49 (0)8153 28 2828 e-mail: Susanne.Lehner@dlr.de Thomas Loubrieu Ifremer thomas.loubrieu@ifremer.fr Frank Melger ARGOSS tel  +31 527 242299 email melger@argoss.nl Flavio Parmiggiani ISAO-CNR +39 051 639 8009 Johannes Schulz-Stellenfleth DLR Tel.  : +49 (0)8153 28 2740 Nicholas Walker ESA-ESRIN Tel: +39 941 80 590 Email: nicholas.walker@esa.int Manfred Zink ESA-ESTEC ) Phone: +31 71 565 3038 Email: manfred.zink@esa.int Team Members: Contact Details 2

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