european service for ocean colour

GlobColour overview and achievements after two yearsGlobcolour / Medspiration user consultation, Nov. 20-22, 2007, Oslo

Session 2 – Progress with the GlobColour Service – November 20, 20071

European Service for Ocean Colour

User Consultation Meeting (Medspiration-5, GlobColour-2)

GlobColour Overview and achievements after two years

Odile Fanton d’Andon (ACRI-ST)

Diagram/illustration

www.globcolour.info

Session 2 – GlobColour Progress

20 November 2007

www.globcolour.info



European Service for Ocean Colour

User Consultation Meeting (Medspiration-5, GlobColour-2)

Background of GlobColourPhase 1 achievementsPhase 2 achievements Provision of a long time-series

(1997-2007) of consistently calibrated and merged global ocean colour products

Validation and characterisation performed with available in situ observations

Perspective : Pre-operational ocean colour service element of the future EU GMES Marine Core Service

Outline of this presentation

July 2002

October 2002



Satisfy emerging demand for validated merged ocean colour derived information

Demonstrate the current state of the art in merging together data streams from different ocean-colour sensors:

MERIS (ESA), SeaWiFS (NASA), MODIS-AQUA (NASA), (Polder-Parasol CNES)

ESA DUE project i.e. driven by end users: IOCCG, IOCCP,UK Met-Office, …

Context

Objectives

Background of GlobColour

Provide a long time-series (10 years) of ocean-colour information

Demonstrate a global NRT ocean-colour service based on merged satellite data

Put in place the capacity to continue production of such time series inthe future and to prepare for full exploitation of Sentinel 3 (ESA)



CONSORTIUM

ACRI-ST (France) Prime contractor / managementProcessor / Production

University of Plymouth (UK) User requirements follow up/

design justification / merging

ARGANS LIMITED (UK) New products / Evolution /merging

NIVA (Norway) Validation (DDS)

Brockman Consult (Germany) Tools developmentWeb server

ICESS (USA), DLR (Germany) & LOV (France)Scientific support


ARGANS



GlobColourDUE project – 3 years - 3 phases

Phase 1 (2006) : Demonstration of feasibility

Today : Second GlobColour User consultation at NIVA

Phase 2 (2007) : Generation and validation of 10 year time series

Phase 3 (2008) : Daily delivery of global merged ocean colour products

NRT demonstration

Delivery to operational oceanography user community


Towards a sustainable European Ocean Colour service part of the future EU GMES Marine Core Service



Users are always involved during the project for consultation, advice andfinal assessment

User meeting at University of East AngliaKO+20: July 2007

User meeting at UK Met OfficeKO+16: Mar. 2007

Participation in the GlobColour User Workshop 3 (ESRIN)KO+36: Nov. 2008

Participation in the GlobColour User Workshop 2 (NIVA)KO+24: Nov. 2007

User assessment of the Final Product Set (10 years)KO+23: Oct. 2007

Participation in the end of phase 1 review (advisors to ESA) and GlobColour User Workshop 1 (LOV)

User assessment of the Preliminary Product Sets (radiance and biophysical) and selection of final product

KO+13: Dec. 2006

Participation in the Critical Design ReviewKO+8: July 2006

Generation and review of Requirements Baseline Document, Design Justification File, and Validation Protocol

KO+2: Jan. 2006

User’s involvement Background of GlobColour



Difficulties

Sensors are not created equal: different designs, calibrations, algorithms, accuracies,….

Large volumes of data to deal with

Merging procedure should not create

biases, discontinuities, artifacts,…




Sensor characterisation (continued in Phase 2)

For validation / characterisation: DDS: Diagnostic Data SetData Courtesy

SeaPRISM [Giuseppe Zibordi, Brent Holben, Doug Vandemark]


see Samantha Lavender’s presentation




Sensor characterisation (continued in Phase 2)

Achievement: Statistical uncertainties have been derived and

are used for merging



Main modules:

Data acquisition Pre-processing Spatial binning Temporal binning Merging QC

MERISL2

SeaWIFSOcean color L2

AquaOcean color L2

ParasolOcean Color L2

Preprocessing Preprocessing Preprocessing Preprocessing

(1) Spatial binning

(2) Temporal binningin daily mode

(3) Merging

(4) Temporal binningin periodic mode

MERISL3 track

SeaWIFSL3 track

MODIS/AquaL3 track

ParasolL3 track

MERISL3 daily

SeaWIFSL3 daily

MODIS/AquaL3 daily

POLDEROcean Color L3d

Daily merged4.63km/0.25°/1°/QL

8-days4.63km/0.25°/1°/QL

Monthly4.63km/0.25°/1°/QL

DDS L2Sensor (4.63km)

DDS L3Merged (4.63km)

DDS L2Sensor (1km)Diagnostic

sites table

Level 3 data archive

Level 2 data archive

DDS data archive

Daily level 3 data cache

DDS L3Sensor (4.63km)

Developing the system Globcolour processor

End 2006:

System is ready for systematic production




GlobCOLOUR ProjectEuropean Node for global Ocean Colour

• Data access• Data products• Methods• Data tools• Calendar• About the Project• Workshops and forum

WWW.globcolour.infoThe European Service for Ocean ColourGlobColour is an ESA Data User Element Project

The GlobColour project is demonstrating an EO based service supporting global ocean carbon cycle research. Through this web portal, the project provides scientists with a long time series of consistently calibrated global

ocean colour information.



Merging recommendations:

Normalized water-leaving radiances:- Statistics are slightly better when using the weighted average than the simple average- Use of the weighted average for the nLw’s

Chlorophyll:- GSM01 provides the best fit to in-situ chlorophyll- It has the advantage of providing other products- Pixel-by-pixel error bars can be provided in the future

- Produce also weighted average Chlorophyll

CHL2 AVG Apr03

CHL1 GSM Apr03




Phase 1 (2006) Demonstration of feasibility successfully achieved

Presentation of the precursor serviceFirst user’s workshop at LOV, Villefranche, 4-6 Dec. 2006



1997-2007 time series available at http://www.globcolour.info

Phase 2 (2007) : Generation and validation of 10 year time series

Phase 2 (2007) Provision of a long time-series (1997-2007)

SeaWiFS

MODIS

MERIS

97-09 07-12see Gilbert Barrot’s presentation



Global ocean colour data set at 4.6 km resolution covering 1997-2007 daily, weekly, monthly products:

•Chlorophyll concentration (Chla)•Diffuse attenuation coefficient @ 490nm (Kd490)

•Total Suspended Matter•CDM absorption (aCDM443)•Particle backscattering coefficient (bbp443)•Aerosol Optical Thickness (T865)•Exact normalised water-leaving radiance @ 412, 443, 490, 510, 531, 555, 620nm•Water-leaving radiance @ 670, 681, 709nm•Data quality flags •Cloud fraction •Excess of radiance at ~ 555 nm (turbidity index) (EL555) •Error estimates per pixel for each layer

MODIS-only, MERIS-onlysee Gilbert Barrot’s presentation

Phase 2 (2007)GlobColour products (1997-2007)

distributed to the users



Some numbers..

More than 25 Tb of input data (level 2)14 Tb of intermediate and output products4.5 Tb of distributed data

netCDF, JPG/PNG

web, ftp, Google-Earthdedicated tools are available(ISIN-PC grids)

All Google Earth tools are available (e.g. ruler, places name…)

Phase 2 (2007) Provision of a long time-series (1997-2007)



Applying the Validation protocol defined in Phase 1

Using: •punctual in situ measurements and •time series obtained from long-term buoy measurements or from regular/ continuous cruises (e.g. ferrybox datasets)

Validation of FPS merged products: •Focus on chlorophyll-a, diffuse attenuation coefficient, normalised water-leaving radiances (LwN). •Perspectives on error uncertainties (See A. Mangin/S. Maritorena talks)

Phase 2 (2007) Validation



Open ocean : see David Antoine presentation


- Based on the match up with the global data set of field data (Chl and nLw’s), the GlobColour FPS is validated.

- The GlobColour FPS is definitely qualified and usable for operational uses, such as assimilation into global models (there is a pixel-by-pixel error bar delivered with the GSM Chl), or delivery of GMES services.

N 175R2 0.84RMS 0.21BIAS 0.04

N 162R2 0.90RMS 0.19BIAS -0.04

N 108R2 0.84RMS 0.14BIAS 0.01

GSMAVWError characterisation




Coastal waters : see Dominique Durand presentation

• A better in-situ dataset for coastal case 2 waters is needed (best results from Ferrybox data collection)!

•GSM01 merging algorithm seems quite robust over coastal waters

•GlobColour merged products show a potential for investigating seasonal to inter-annual variability in coastal zone: should be investigated further !

NIVA-FerryBox CHL monthly mean



Inter-comparison with other similar initiatives (NASA, REASoN) : see Stephane presentation




Quality control and uncertainty estimation

Add SensorErrorFrom

Charact.& anc. data

GlobColourThe global OC data service in the European Marine Core Service

Parallel & consistent with the Medspiration/GHRSST approach

L3 Products

per sensor

net

CD

F f

orm

at

Input L2 data of Varied format

& with no errors estimates

MergedProducts with error estimates

net

CD

F f

orm

atDatamerging

Observations ApplicationsSee session 4 tomorrow



Thank youfor yourattention

http://www.globcolour.info/



Monthly ChlorophyllMay 2006



Error estimates at pixel level (%)Chla – May 2006

100%

50%

0%

european service for ocean colour

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