BIO-OPTICAL PRODUCT VALIDATION Emanuele Organelli *, Hervé Claustre, Annick Bricaud, Catherine Schmechtig 2, Antoine Poteau, Romain Serra 3, Antoine Mangin 3, Xiaogang Xing 4, Fabrizio D Ortenzio, Louis Prieur, Grigor Obolensky, Giorgio Dall Olmo 5, Marie Barbieux, Julia Uitz, Edouard Leymarie, Christophe Penkerc h Laboratoire d Océanographie de Villefranche (LOV), UMR 7093, CNRS and Université Pierre et Marie Curie, Paris 6, Villefranche sur Mer, FRANCE 2 Observatoire des Sciences de l Univers, Paris Centre, Ecce-Terra, UMS 3455 FRANCE 3 ACRI-ST, 260 route du Pin Montard, 06904 Sophia Antipolis, FRANCE 4 Takuvik Joint International Laboratory, UMI 3376, Université Laval and CNRS, Québec City GV 0A6, CANADA 5 Plymouth Marine Laboratory, Plymouth, PL 3DH, UK *organelli@obs-vlfr.fr
Overview OCR-504 Multispectral radiometer (Satlantic Inc.) E d (380) E d (42) E d (490) PAR «PROVOR CTS-4» type (NKE, France)
Overview OCR-504 Multispectral radiometer (Satlantic Inc.) E d (380) E d (42) E d (490) PAR 85 Bio-Argo floats 737 profiles for each radiometric channel «PROVOR CTS-4» type (NKE, France) a total of 29484 profiles in 2.5 years
Overview This high number of autonomous measurements in very diverse open ocean systems can be a useful resource for: defining the bio-optical status of the ocean (i.e., regions characterized by bio-optical anomalies) validating OCR-derived products (e.g., Kd coefficients) understanding biogeochemical processes (e.g., primary production) As these radiometric data are collected out of operator s control and regardless of metereological conditions, a QUALITY-CONTROL is mandatory before any use.
Quality-Control Main issues: Unknown sea and sky conditions No simultaneous above water E d measurements No routine or post-deployment dark readings Most of the procedures for quality-controlling radiometry measurements contained in the «Ocean Optics Protocols for Satellite Ocean Color Sensors Validation» handbook (Mueller et al., 2003) need to be adapted.
Depth (m) Depth (m) Depth (m) Quality-Control A specific and automatic data quality-control procedure is developed for identifying: bad profiles clouds wave focusing CLOUDS PAR E d (λ); PAR E d (490) E d (λ) values are expressed as μw cm -2 nm - ; PAR values are expressed as μmol quanta m -2 s - Organelli et al., in preparation
Depth (m) Depth (m) Depth (m) Quality-Control Good performances are observed across the global ocean Good performances for each radiometric channel 60% of profiles passed the QC (including those cleaned by clouds and wave focusing) E d (380)_QC E d (42)_QC E d (490)_QC E d (380)_measured E d (λ) values are expressed as μw cm -2 nm - E d (42)_measured E d (490)_measured Organelli et al., in preparation
Radiometer performances and Products E d (380) E d (42) E d (490) E d (380) E d (42) E d (490) E d (0 + ) in agreement with the Gregg and Carder (990) model Mediterranean Sea South Atlantic Sub-Tropical Gyre E d (380) 250 200 50 00 50 0 Bio-Argo floats Gregg & Carder 05/3 0/4 09/4 05/5 E d (380) 250 200 50 00 50 0 Bio-Argo floats Gregg & Carder 0/2 06/3 02/4 0/4 06/5 E d (42) 250 200 50 00 50 0 05/3 0/4 09/4 05/5 E d (42) 250 200 50 00 50 0 0/2 06/3 02/4 0/4 06/5 E d (490) 250 200 50 00 50 0 05/3 0/4 09/4 05/5 E d (490) 250 200 50 00 50 0 0/2 06/3 02/4 0/4 06/5 E d (λ) values are expressed as μw cm -2 nm - No evident instrumental drift impacting at the surface No biofouling
Radiometer performances and Products E d (380) E d (42) E d (490) E d (380) E d (42) E d (490) Depth (m) E d (0 + ) in agreement with the Gregg and Carder (990) model E d (380) 250 200 50 00 50 0 Mediterranean Sea Bio-Argo floats Gregg & Carder 05/3 0/4 09/4 05/5 South Atlantic Sub-Tropical Gyre E d (380) 250 200 50 00 50 0 Bio-Argo floats Gregg & Carder 0/2 06/3 02/4 0/4 06/5 K d (λ) in 4 layers: first optical depth 0% of PAR(0 - ) % of PAR (0 - ) % of PAR (0 - ) Chlorophyll (mg m -3 ) E d (42) 250 200 50 00 50 0 05/3 0/4 09/4 05/5 E d (42) 250 200 50 00 50 0 0/2 06/3 02/4 0/4 06/5 Z pd 0% E d (490) 250 200 50 00 50 0 05/3 0/4 09/4 05/5 E d (490) 250 200 50 00 50 0 0/2 06/3 02/4 0/4 06/5 % % E d (λ) values are expressed as μw cm -2 nm - No evident instrumental drift impacting at the surface No biofouling K d (m - )
K bio (K d (λ)-k w (λ)) at the global scale 2D Graph K bio (380) (m - ) K bio (380) (m - ) r 2 =0.85 n=222 K bio (380) (m - ) 0.6 0.5 0.4 0.3 0.2 Bio-Argo floats 0.0 Morel and Maritorena 200 0.0 0.2 0.3 0.4 0.5 0.6 Black Sea Mediterranean Sea North Atlantic Sub Polar Gyre North Atlantic Sub Tropical Gyre North Atlantic South Atlantic Sub Tropical Gyre South Atlantic South Pacific Austral Ocean (Atlantic sector) Austral Ocean (Indian sector) K bio (490) (m - ) K bio (490) (m - ) FIRST OPTICAL DEPTH K bio (490) (m - ) K d (380) are higher than K d (490), in agreement with global bio-optical models (e.g., Morel and Maritorena, 200). Differences appear among regions.
Regional vs Global scale Kbio(380) (m ) North Atlantic Sub-Polar Gyre Black Sea GLOBAL - - North Atlantic Sub-Tropical Gyre - 0.0 0.0 0.00 0.00 Western Mediterranean Sea 0.0 - Kbio(490) (m ) - Kbio(490) (m ) 0.0 South Atlantic Sub-Tropical Gyre - 0.00 0.00 Kbio(380) (m ) 0.0 0.0 0.00 0.00 0.0 - Kbio(490) (m ) Austral Ocean (Atlantic Sector) - Kbio(490) (m ) 0.0 0.00 0.00-0.0 0.0 0.00 0.00 0.0 - South Pacific Austral Ocean (Indian Sector) - Kbio(380) (m ) 0.00 0.00 0.0 Kbio(490) (m ) - 0.0 - Kbio(490) (m ) Kbio(380) (m ) Kbio(380) (m ) Eastern Mediterranean Sea - 0.00 0.00 Kbio(380) (m ) Kbio(380) (m ) 0.0 - Kbio(380) (m ) Kbio(380) (m ) - Kbio(490) (m ) 0.0 0.00 0.00 0.0 0.0 0.00 0.00 - Kbio(490) (m ) 8th June 205, San Francisco, CA, USA 0.0 - Kbio(490) (m )
Bio-optical behaviour of oceans North Atlantic Sub-Polar Gyre Mediterranean Sea North Atlantic Sub-Tropical Gyre Bio-Argo floats Morel and Maritorena (200) Austral Ocean South Atlantic Sub-Tropical Gyre
Bio-optical behaviour of oceans The bio-optical behaviour is different among various oceanic areas Seasonality can be observed within regions Bio-Argo floats have the potential for identifying oceanic regions with optical properties departing from global bio-optical relationships Implications for ocean color applications
OCR product validation Radiometric measurements by Bio-Argo floats are also a useful resource for validating satellite products
K d (490) (m - ) from GlobColour OCR product validation Radiometric measurements by Bio-Argo floats are also a useful resource for validating satellite products y=0.96x+0.02 r 2 =0.83 n=749 Mediterranean Sea North Atlantic Sub Polar Gyre North Atlantic Sub Tropical Gyre North Atlantic South Atlantic Sub Tropical Gyre South Atlantic Austral Ocean (Atlantic sector) Good agreement between K d (490) values from Bio-Argo floats and those from GlobColour, but satellite overestimates low in situ Kd values. K d (490) (m - ) from Bio-Argo floats GlobColour data kindly provided by Romain Serra and Antoine Mangin (ACRI-ST)
Summary and strategies...
Summary and Strategies Bio-Argo floats supply the ocean color community with thousands of radiometric data in a very short time Through a statistical approach, it is possible to: Identify regions with bio-optical anomalies and where difficulties in retrieving biogeochemical parameters from satellite data could be encountered Validate OCR products Delineation of «anomalous» regions can be useful to plan dedicated cruises, for setting mooring buoys (like BOUSSOLE and MOBY) or using CAL/VAL floats (ProVal) in order to improve Ocean Color applications
Some perspectives...
K bio (380)/K bio (42) K bio (380) (m - ) K bio (380)/K bio (42) Perspectives: the use of E d (42) GLOBAL y=.09x r 2 =0.96 n=92 North Atlantic Sub-Polar Gyre K bio (42) (m - ) K bio (490) (m - ) Sub-Tropical Gyres K d values at 42 nm could be useful for better understanding the influence of CDOM and algal pigments in light attenuation and its variability across the oceans. K bio (490) (m - )
Perspectives: IOPs and bio-optical variables b bp (700) (m - ) Radiometric measurements can be connected to other simultaneously measured key biogeochemical and bio-optical variables: Chlorophyll a Fluorescence CDOM Fluorescence Particle Backscattering coefficient Particle Attenuation coefficient 0.008 0.006 Particle Backscattering in the MLD 0 m CDOM 0.004 Gulf of Lions (Med Sea) in summer b bp (700) 0.002 0.000 NASPG Bloom MED NoBloom 3 MED NoBloom MED NASTG SASTG Chl a Analysis by Marie Barbieux (LOV) 00 m
depth 50 m 00 m 50 m 0 m -50-00 -50 0 depth 50 m 00 m 50 m 0 m -50-00 -50 0 Perspectives: ProVal floats Specifically designed for Ocean Color data validation (CAL/VAL) Useful for application of bio-optical inversion models using in situ Rrs(λ) measurements Useful for studying areas with bio-optical anomalies: ProVal in the Mediterranean Sea 2 ProVal in the Austral Ocean E d -L u (7λ) E d -L u (7λ) IRRADIANCE RADIANCE 665 nm 560 nm 42 nm Irradiance (0 profiles) 400 nm IRR400 IRR42 IRR443 IRR490 IRR50 IRR560 IRR665 Radiance (0 profiles) e-02 e-0 e+00 e+0 e+02 5e-04 5e-03 5e-02 5e-0 Irradiance Radiance E d (λ) 443 nm 490 nm 50 nm 665 nm 400 nm L u (λ) 443 nm 42 nm 50 nm 560 nm 490 nm RAD400 RAD42 RAD443 RAD490 RAD50 RAD560 RAD665 Data by Edouard Leymarie (LOV) 380/400 nm 42 nm 443 nm 490 nm 50 nm 560 nm 665 nm
All these activities are a contribution to several projects: and also: Bio-Argo France, UK Bio-Argo, Argo-Italy, E-AIMS and ProVal projects. Thanks to all funding organizations:
A big thank to all people contributed to this presentation... L A. Bricaud A. Poteau M. Barbieux L. Prieur C. Penkerc h O H. Claustre V C. Schmetchtig F. D Ortenzio J. Uitz G. Obolensky E. Leymarie Takuvik/Univ. China PML R. Serra X. Xing A. Mangin G. Dall Olmo
Thanks for your attention!