Transcript Aucun titre de diapositive - Observatoire Océanologique de

BOUSSOLE: status of activities
in April of 2008
MERIS, March 4, 2003, © ESA
David ANTOINE
Laboratoire d’Océanographie de Villefranche
MERIS data QWG, ESRIN, Frascati, 21-23 April
Outline
 A few reminders about the project
 Facts
 Science exploitation
 Cal / val operations
 Conclusions / perspectives
MERIS data QWG, ESRIN, Frascati, 21-23 April
Extracts from a NOAA/NASA/NIST workshop
« Achieving satellite instrument calibration for climate
change »
et al., 2007,
How is the EarthOhring
changing
and EOS
whatTrans
are AGU
the consequences
for life on Earth?
 How is the global Earth system changing?
 What are the primary causes of change in the Earth
system?
 How does the Earth system respond to natural and
human-induced changes?
 What are the consequences of changes in the Earth
system for human civilization?
 How well can we predict future changes to the Earth
system?
The answers to these questions rely on Cal/Val
MERIS data QWG, ESRIN, Frascati, 21-23 April
That’s what is done for altimetry
Extrait du site AVISO/CLS, http://www.jason.oceanobs.com/html/actualites/indic/msl/welcome_fr.html
MERIS data QWG, ESRIN, Frascati, 21-23 April
1st comment / message
 Maintaining calibration of ocean color sensors is a
major activity that cannot be neglected or
considered just as a basic duty of space Agencies
 Researcher must be involved closely with space
Agencies
 This is a key to answer correctly to present
questions on the present and future changes of
ocean biogeochemistry and their responses to
global environment changes
 This is not so obvious.. Nothing is granted in this
domain
MERIS data QWG, ESRIN, Frascati, 21-23 April
BOUSSOLE: motivations
Establishing a time series of inherent and
apparent optical properties (IOPs and
AOPs), with two parallel objectives :
- Science objectives : short-term changes in IOPs and
AOPs, relationships between both, role of CDOM,
seasonal and inter-annual changes, bidirectionality of
the ocean reflectance...
- Operational objective : vicarious calibration of
ocean color observations from space, and validation
of the level-2 “geophysical products” (e.g.,
chlorophyll, normalized radiances).
MERIS data QWG, ESRIN, Frascati, 21-23 April
BOUSSOLE: strategy
Combination of 3 elements :
- A deep sea mooring, collecting data on a “continuous” b
- Monthly cruises for collecting data that are not
accessible to the mooring (vertical profiles, water
sampling), as well as for servicing the mooring
- A coastal AERONET station, providing the
necessary information about the aerosol properties,
which are a central element of the vicarious
calibration process
MERIS data QWG, ESRIN, Frascati, 21-23 April
The site (43°22’N; 7°54’E)
Deep (2400 m) Case 1 waters
MERIS data QWG, ESRIN, Frascati, 21-23 April
Water at BOUSSOLE are permanently Case 1 waters
Morel & Maritorena, 2001
Upper limit for Case 1 waters
Buoy data
MERIS data QWG, ESRIN, Frascati, 21-23 April
The range of bio-optical properties at BOUSSOLE is
representative of global Case 1 waters
Thick line : BOUSSOLE
Thin line and thin dotted line : SeaWiFS global or Med Sea only
Gray : NOMAD
MERIS data QWG, ESRIN, Frascati, 21-23 April
25 mètres
Ombrage minimal par
la bouée elle-même
-4 m
radiomètres
radiomètres
Acquisition “en
rafale”
(1 minute à 6 Hz) :
Possibilité de filtrer
l’effet de l’interface
pour s’approcher de
la valeur réelle de Kd
ou Ku, et donc de
réaliser une meilleure
-9 m
MERIS data QWG, ESRIN, Frascati, 21-23 April
BOUSSOLE buoy: some illustrations
MERIS data QWG, ESRIN, Frascati, 21-23 April
Measurements, instruments:
Monthly cruises
Vertical profiles:
 T, S, O2, chlorophyll fluorescence (CTD)
 Ed & Eu at 13 l (Satlantic SPMR/SMSR), Secchi disk
 Phytoplancton pigments (HPLC)
 phytoplancton absorption (filters)
 CDOM absorption
 Total absorption & attenuation @ 9 l (Wetlabs’ AC9)
 Backscattering coefficient (Wetlabs’ eco VSF)
 CDOM fluorescence (Wetlabs’ CDOM WetStar).
Surface:
 Dry weight of particles (SPM)
 AOT (CIMEL CE-317 or SIMBADA).
 Lw determined from above the surface (SIMBADA)
AERONET
 Photometer CE-318 : AOT, aerosol types
MERIS data QWG, ESRIN, Frascati, 21-23 April
Measurements, instruments : buoy
italics: evolutions in 2008
 Ed, Eu, Lu @ 7 l (Satlantic 200 series), @ 4 & 9 m (+ reference
above the surface) (Lu hyperspectral from 350 to 800 nm,
resolution 2 nm)
 PAR sensor
 Attenuation coefficient @ 660 nm (4 & 9 m)
 phytoplankton fluorescence (4 & 9 m)
 Backscattering coefficient @ 443 et 560 (9 m) (442, 488, 555 &
620 nm)
 Temperature, salinity, pressure
 Tilt & heading of the buoy
 Mooring cable strain
MERIS data QWG, ESRIN, Frascati, 21-23 April
Work at sea
 70 monthly cruises (since july 2001; Tethys-II)
15 buoy deployment / recovery cruises (ship: castor 02)
 40 opportunity cruises (1-2 days) for verifications / repairs /
cleaning etc…
 17-days AOPEX cruise (Suroit, Août 2004)
Buoy deployments
 Over 1460 days since september of 2003, the buoy was
continuously deployed (except Janv. Fev 2004), and has
functioned during 1250 days, i.e., a 85% success rate
MERIS data QWG, ESRIN, Frascati, 21-23 April
But 2008 came..
 Mid January: ship collision: the buoy is recovered immediately
(the upper superstructure that host the instrumentation)
 One month later: the mooring line breaks: the lower part of the
buoy (main floatation) + the mooring line are recovered
At the end: no loss of instrumentation
Buoys are being checked, repaired and prepared for redeployment
The instrument suite is being checked by Satlantic
Redeployment is planned in June
At the end, this is a 5-months interruption of the data flow…
MERIS data QWG, ESRIN, Frascati, 21-23 April
Since
January of 2007
http://www.obs-vlfr.fr/Boussole
MERIS data QWG, ESRIN, Frascati, 21-23 April
BOUSSOLE: publications
Antoine, D. M. Chami, H. Claustre, F. D’Ortenzio, A. Morel, G. Bécu, B. Gentili, F. Louis, J. Ras, E. Roussier, A.J.
Scott, D. Tailliez, S. B. Hooker, P. Guevel, J.-F. Desté, C. Dempsey and D. Adams. 2006, BOUSSOLE : a
joint CNRS-INSU, ESA, CNES and NASA Ocean Color Calibration And Validation Activity. NASA Technical
memorandum N° 2006–214147, 61 pp.
Voss, K., A. Morel and D. Antoine, Detailed validation of the bidirectional effect in various Case 1 waters for
application to Ocean Color imagery, Biogeosciences, , 4, 781-789.
Morel A., H. Claustre, D. Antoine, B. Gentili, Attenuation and reflectance properties within the visible and near-UV
spectral domains, as determined in south Pacific waters, and compared with those in some other oceanic
zones, Biogeosciences, 4, 913-925.
Antoine, D., P. Guevel, J.-F. Desté, G. Bécu, F. Louis, A.J. Scott and P. Bardey, The « BOUSSOLE » buoy – A new
transparent-to-swell taut mooring dedicated to marine optics : design, tests and performance at sea, sous
presse à Journal of Atmospheric and Oceanic Technology.
Antoine, D., F. D’Ortenzio, S.B. Hooker, G. Bécu, B. Gentili, D. Tailliez andA. Scott, Assessment of uncertainty in
the ocean reflectance determined by three satellite ocean color sensors (MERIS, SeaWiFS, MODIS) at an
offshore site in the Mediterranean Sea (BOUSSOLE project), accepté à Journal of Geophysical
Research.
Bailey S., S.B. Hooker, D. Antoine, J.P. Werdell and B. Franz, Vicarious calibration of ocean color satellite remote
sensors: An analysis of sources and assumptions, soumis à Applied Optics.
Antoine D., and P. Gernez, Field characterization of wave-induced underwater light field fluctuations, en
préparation pour Journal of Geophysical Research, Oceans.
Banzon, V., D. Antoine, C. Kuchinke, K. Voss, H.R. Gordon and R.H. Evans, Application of a dust-correction
algorithm for SeaWiFS in the Mediterranean Sea : when is it appropriate ? en préparation pour Journal of
Geophysical Research, Oceans.
MERIS data QWG, ESRIN, Frascati, 21-23 April
Cal / val operations
for:
- ENVISAT – MERIS, ESA
- SeaWiFS, NASA
- MODIS-A, NASA
- PARASOL – POLDER3, CNES
In a « near » future:
- Sentinel3 – OLCI, ESA (2012)
Also, likely for:
- OCM-2, ISRO
- CNSA sensors
- Future geostationary sensor above europe (CNES..)
MERIS data QWG, ESRIN, Frascati, 21-23 April
Cal / val operations
MERIS
SeaWiFS
Identification of the
« blue
overestimation » for
MERIS.
Antoine, D., F. D’Ortenzio, S.B.
Hooker, G. Bécu, B. Gentili, D.
Tailliez and A.J. Scott, 2008,
Assessment of uncertainty in the
water-leaving reflectance
determined by thfree satellite
ocean color sensors (MERIS,
SeaWiFS, MODIS-A) at an
offshore site in the Mediterranean
Sea (BOUSSOLE project),
Journal of Geophysical
Research, Oceans, in press
MODIS
MERIS data QWG, ESRIN, Frascati, 21-23 April
Cal / val operations
Comparaison of vicarious cal gains obtained with MOBY,
BOUSSOLE & NOMAD
Bailey, S., S.B. Hooker, D. Antoine, B.A. Franz, and P.J. Werdell, Sources and
assumptions for the , 2008, vicarious calibration of ocean color satellite
observations, Applied Optics Vol. 47, No. 12, 2035-2045.
MERIS data QWG, ESRIN, Frascati, 21-23 April
Cal / val operations
MAY 2006
AOT<0.1
AOT>0.1
NOV 2006
« Qualité des produits de réflectances marine issus de POLDER3 / PARASOL », présentation faite
le 18 décembre 2006 au CNES par F Steinmetz et P.-Y. Deschamps
MERIS data QWG, ESRIN, Frascati, 21-23 April
Characterization of uncertainties in products
(chlorophyll for instance) from different missions
Needed before data from different sensors can be merged
(e.g., GlobCOLOUR)
Merged products MERIS / MODIS / SeaWiFS, july
2002
MERIS data QWG, ESRIN, Frascati, 21-23 April
In summary
 Development & qualification of a new measurement platform, dedicated
to marine optics
 Set up of a staff & scientific teams
 The system is quasi-operational, with two “sister buoys” and moorings
 continuous acquisition
 Data production as requested by space Agencies (cal/val)
 Scientific exploitation is being developed
 International recognition is achieved
 The use of the data is developing regularly
 The project will continue in the coming years
MERIS data QWG, ESRIN, Frascati, 21-23 April
Thank you
MERIS data QWG, ESRIN, Frascati, 21-23 April
People (LOV+OOV+external partnerships)
P.I. (L.O.V., Villefranche sur mer) Equipe “Optique marine et télédétection”
 David ANTOINE,
Etudiants, post-Docs
 Pierre Gernez (thèse P6)
 Terry O’Bree (post Doc; démarrage septembre 2007)
Equipe technique (L.O.V. et O.O.V., Villefranche sur mer)
100% BOUSSOLE
 Guislain BECU,
Responsable campagnes en mer, traitement des données (20042007)
 Enzo VELLUCCI
idem, depuis octobre 2007
CDD CNES et ESA
Contributions variables (10 à 50%), partagées avec les autres activités du LOV
 Bernard GENTILI,
Traitement des données
 Francis LOUIS,
Electronique, divers
 Joséphine RAS,
Mesures HPLC et absorption sur filtre
 Dominique TAILLIEZ ,
CTD + IOPs, campagnes mensuelles
 David LUQUET,
Plongée
Partenariats entreprises
 Pierre GUEVEL,
 Jean-François DESTE,
 Philippe BARDEY,
 Ludovic BOURG, Grigor
 Alpha CAMARA,
 Cyril DEMPSEY,
 Darrell ADAMS,
ACRI-st-Genimar, conception bouée, calculs hydro
ACRI-st-Genimar, ingénierie bouée
ACRI-st, Expertise
OBOLENSKY, ACRI-st, traitement données MERIS
“Avance Conceptuelle”, conception bouée, calculs de structure
Satlantic Inc., instrumentation optique
MERIS data QWG, ESRIN, Frascati, 21-23 April
Satlantic Inc. instrumentation optique
Other people, collaborations
Equipe scientifique (L.O.V., Villefranche sur mer) Equipe “Optique marine et
télédétection”
 Marcel BABIN,
fluorescence du phytoplancton
 Annick BRICAUD,
IOPs (absorption)
 Malik CHAMI,
étalonnage indirect, polarisation
 Hervé CLAUSTRE,
IOPs, “proxys biogeochimiques”, nouvelles plateformes
 Fabrizio d’ORTENZIO Cal/val, relations physique-optique
 André MOREL,
AOPs
Collaborations Nationales
 P. Y. DESCHAMPS et al. LOA, Univ. Lille Above-water vs below-water, PARASOL
 H. LOISEL et al.
ELICO, WimereuxIOPs
 C. MOULIN
LSCE, Paris
Projet PFT-Med (LEFE-CYBER)
Collaborations Internationales
 Stanford B. HOOKER NASA/GSFC
Optics protocols, cal/val operations
 Kenneth J. VOSS
Univ. Miami
Bidirectionalité
 Robert FROUIN
Scripps
Corrections atm., PAR
 Dave SIEGEL
UCSB
CDOM
 Chuck TREES
NURC, La Spezia Campagne 2008 (SORTIE)
MERIS data QWG, ESRIN, Frascati, 21-23 April
Funding Angencies
Agence Spatiale Européenne
Centre National d’Etudes Spatiales
National Aeronautics and Space Administration of the USA
Centre National de la Recherche Scientifique
Institut National des Sciences de l’Univers
Université Pierre et Marie Curie
Observatoire Océanologique de Villefranche sur mer
MERIS data QWG, ESRIN, Frascati, 21-23 April