regional chlorophyll retrieval algorithms for north sea waters ...€¦ · 12 pin_1 pin_2 pin_3...
TRANSCRIPT
MERIS & AATSR Symposium * Frascati * 27.09.2005
ENVIRONMENTAL INFORMATICSGEOINFORMATION PRODUCTS
IVM /BROCKMANN CONSULT
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison
and validation
S. Peters, C. Brockmann, M. Eleveld, R. Pasterkamp, H. Van der Woerd, K. Ruddick, Y.Park, T. Block, R. Doerffer, H. Krasemann, R. Roettgers,
W.Schoenfeld, P. Joergensen, G. Tilstone, V. Martinez-Vicente, G.Moore, K. Soerensen, J. Hokedal, E. Aas
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
REVAMP
Regional Validation of MERIS Chlorophyll Products in North Sea Coastal Waters
In-situ measurements MERIS Data
• Support the monitoring of the eutrophication status of the North Sea• Develop an improved validated chlorophyll product for the North Sea based on MERIS• Parameterise bio-optical models• Extend MERIS validation beyond the ESA validation phase
RegionalProcessing
EU Contract: EGV1-CT-2001-00049
Chlorophyll Atlas
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Regional Algorithms
• Different mathematical models– multispectral colour ratios– radiative transfer model inversion
• look-up table technique• neural network technique• matrix inversion
• Different SIOP data sets– Specific Inherent Optical Properties– algorithm calibration– different optical properties– different distribution of concentration ranges
• REVAMP– locally tuned regional algorithms
• combination of math. model and SIOP calibration data set– North Sea wide comparison
• in-situ data, historical data, MERIS dataREVAMP production processor
inversion technique, LUT, common North Sea SIOP dataset
– REVAMP processor using regional calibration SIOPs
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Calibration Intercomparison
REVAMPOperationalProcessor(inversion method)
MERIS L2Water leavingreflectances
REVAMP-xChl concentration
Region-x
Region-1BelgianCoast
Region-5German
Bight
Region-7Skagerrak
…….. others
SIOP calibration files
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Calibration Intercomparison Study
• Processor: REVAMP operational processor
• 10 different versions of SIOP-calibration files:0 ... operational REVAMP1 ... Belgian Coast SIOPs2 ... Celtic Sea SIOPs3 ... Central North Sea SIOPs4 ... Dutch Coast SIOPs5 ... German Bight SIOPs6 ... Kattegat SIOPs7 ... Skagerrak, OuterOslofjord, Kattegat,North Sea SIOPs8 ... UK Coast SIOPs9 ... West English Channel SIOPs
• 15 MERIS RR products from June – August 20031st Reprocessing 2004 / 2nd reprocessing 2005
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Input Data Summary
1 2 3 4 5 6 7 8 9
No DateBelgium Coast Celtic Sea
Central NS
Dutch Coast
German Bight Kattegat
Skag / Oslo F UK Coast
West Engl. Ch.
1 09.06.2003 x x x2 13.06.2003 x x x x3 25.06.2003 x x x4 04.07.20035 07.07.2003 x6 08.07.2003 x7 10.07.2003 x8 13.07.2003 x x x9 14.07.2003 x x x10 14.07.200311 17.07.2003 x12 06.08.2003 x13 09.08.200314 15.09.2003 x x
x x xx
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Example: Southern NS & Skagerrak, 20030809
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
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REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
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Chl c
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m³]
algal_1algal_2REV0REV1REV2REV3REV4REV5REV6REV7REV8REV9
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Calibration Intercomparison Study
Conclusions from pixels from single images:
Regional algorithms improve Chlorophyll-a estimates
Locally calibrated algorithms perform1) Ok at the calibration locations2) Not as well elsewhere
The alternative (standard) strategy is to build an operationalprocessor based on the best knowledge of SIOPs for the region of application (North Sea).
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Algorithm Calibration: For the operational REVAMP processor we used the median of all SIOP values in the REVAMP database
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phytoplankton absorptionparticle absorptionparticle scatteringCDOM absorption
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Results: 1: Monthly median and maximum Chlorophyll-a mapsApril 2003
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Results: 2: Yearly median and maximum Chlorophyll-a maps 2003
Spring bloomMarch April
June: Coccolithophores
bloom
Phaeocystisbloom
March April
Patchy bloomsOf various
species
Blooms in March and
October
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Results: 3: Regional Time series of monthly median and maximum Chlorophyll-a maps 2003
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Results: 4: Examples of FRImages processed by ACRI to L2 with CHL-a derived from the REVAMP algorithm
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Validation Results: Yearly median CHL-a on regular Dutch monitoring points (visited 1-2 times per month)
Compared with
REVAMP yearly median CHL-a from MERIS RR
The correlation coefficient is approximately 0.93
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Validation Results: Comparing time series in one monitoring point(high CHL and low CHL situation)
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Validation Results: Comparing transect results using data from the FerryBox project
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Providing policy support:Eutrophication problem areas are now defined by the presence of monitoring networks
Satellite results Monitoring network result
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Some Conclusions
• The REVAMP Chlorophyll-a estimates validate quite well in most water types (some problems in areas with high sediment concentrations)
• Using local algorithms for Chlorophyll-a retrieval may solve this problem
• There are large discrepancies in the areal extent of eutrophication between OSPAR maps based on monitoring networks and satellite derived Chlorophyll-a estimates
• Maximum Chlorophyll-a maps provide a wealth of information on blooms occurences
REVAMP IVM/BROCKMANN CONSULT
MERIS & AATSR Symposium * Frascati * 27.09.2005
Regional chlorophyll retrieval algorithms for North Sea waters: intercomparison and validation
Acknowledgements
ESA and ACRI are thanked for MERIS image provision
All REVAMP colleagues are gratefully acknowledged for their contributions to the project
All captains, crews and companies/organisations that have helped us tocollect data on ships of opportunity
The REVAMP Quality Assurance Committee (Mike Rast, Eon O’Mongain and Hartmut Heinrich) have earned our thanks and appreciations for many interesting discussions and for keeping us in line.
We thank the EC for funding this very interesting project