Page 1GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Full product set validation over coastal Case II waters Dominique Durand, Are Folkestad, Jo Høkedal, Kai Sørensen NIVA Samantha Lavender Univ. Plymouth,
Page 2GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Scope The FPS dataset DDS for coastal case II waters Validation against in-situ data –global assessment –Regional and water type approach –Specific results at diagnostic sites Relative validation against pre-merged data 10-year time series Conclusions
Page 3GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST FPS dataset 10-year of global observations –SeaWiFS: –MODIS: –MERIS: Use of an extended in-situ dataset to try to ensure a robust and statistically sounded validation –OBPG, NOMAD, Boussole –Several coastal DDS
Page 4GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST The GlobCOLOUR products
Page 5GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST GlobColour products
Page 6GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST The flags
Page 7GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Level-2 Characterisation Chl-a Results Achievement: Statistical uncertainties have been derived and are used for merging
Page 8GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Types of In Situ Data Chlorophyll (HPLC and in-vitro fluorometric) Fully normalised water-leaving radiance primarily at 412, 443, 490, 510, 531, 555, 620, 670 nm –Computed when Lw, Ed, Es, Chl, and solar and viewing geometry available. Diffuse attenuation coefficient at ~490nm Dissolved Coloured Organic Material
Page 9GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Identification of Case 2 Validation Sites Selection of sites for Case 2 validation based on general knowledge
Page 10GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST A priori DDS for coastal Case 2 waters Venice Tower (Adriatic Sea) Sopot (Poland) Helgoland (Germany) Skagerrak (NIVA-Ferrybox) Helsinki Light House (Gulf of Finland) Gustav Dahlén Tower (Baltic Sea) CALCOFI (California) Gulf of Maine (USA Canada) MVCO (Rhode Island, Chesapeake Bay) COVE Benguela (South Africa) DDS used for validation of coastal case 2 waters
Page 11GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Identification of Case 2, subclassification Selection of sites for Case 2 validation based on general knowledge Identification of Case 2-S using the EL555 product Case 2-Y flag is not active yet in MERIS RR products
Page 12GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Excess radiance at 555 nm (turbid Case 2 waters)
Page 13GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Number of match-ups per validation site Venice Tower Gustav Dalen Tower Helsinki LightHouse Chesap. Bay Rhode Island NIVA FerryB SkagerrakGlobal Chl hplc Chl fluor GSM Kd CDM Chl hplc Chl fluor L AVW L L L L L
Page 14GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST r RMS 0.36 BIAS 0.13 SLOPE 0.62 OFFSET 0.10 r RMS 0.31 BIAS 0.01 SLOPE 0.69 OFFSET 0.23 r RMS 0.27 BIAS SLOPE 0.72 OFFSET 0.20 r RMS 0.46 BIAS SLOPE 0.60 OFFSET 0.41 r RMS 0.09 BIAS 0.02 SLOPE 0.73 OFFSET 0.03 Validation of nLw over coastal case II waters
Page 15GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST r RMS 0.92 BIAS 0.02 SLOPE 0.38 OFFSET 0.94 r RMS 1.33 BIAS 0.88 SLOPE 0.35 OFFSET 2.37 r RMS 1.12 BIAS SLOPE 0.48 OFFSET 0.69 r RMS 0.81 BIAS 0.48 SLOPE 0.72 OFFSET 1.83 Validation of Chl products over coastal case II waters
Page 16GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Validation of CHL in turbid/ non-turbid coastal waters r RMS 0.55 BIAS SLOPE 0.62 OFFSET 1.06 r RMS 1.09 BIAS 0.11 SLOPE 0.37 OFFSET 0.83 r RMS 1.89 BIAS 1.35 SLOPE 0.56 OFFSET 0.32 r RMS 0.55 BIAS 0.39 SLOPE 0.37 OFFSET 0.83
Page 17GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Chlorophyll : regional analysis
Page 18GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Regional validation of CHL N 520 r RMS 1.54 BIAS 1.09 SLOPE 0.05 OFFSET 1.74 N 1497 r RMS 1.30 BIAS 1.07 SLOPE 0.46 OFFSET 0.66 Helsinki Lighthouse G. Dalen Tower Chesapeake Bay Rhode Island
Page 19GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Relative validation against pre-merged data (Global)
Page 20GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Performance of the GlobCOLOUR products in case 2 waters: CHL – July 2002 All pixels Turbid flag <200m Depth < 200m
Page 21GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Performance of the GlobCOLOUR products in case 2 waters: CDM – July 2002 All pixels Turbid flag <200m Depth < 200m
Page 22GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Performance of the GlobCOLOUR products in case 2 waters: bbp – July 2002 All pixels Turbid flag <200m Depth < 200m
Page 23GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST 10-years time series
Page 24GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST NIVA-FerryBox CHL monthly mean
Page 25GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Conclusions Validation of merged case I products in coastal case II waters presents the same limitations than with non-merged products Validation of daily-averaged products over variable coastal waters is a challenging task –Spatial discrepancy (4.6 km vs. point) –Temporal discrepancy (daily average vs. instantaneous) Discriminate between algorithm weakness and quality of the in-situ dataset has shown to be difficult A better in-situ dataset for coastal case 2 waters is needed –best results so far from Ferrybox data collection GlobColour GSM01 merging algorithm shows to be quite robust over coastal waters (tested so far) GlobColour merged products show a potential for investigating seasonal to inter-annual variability in coastal zone: One of the GlobColour follow-up? In coastal waters with inherent high optical variability, the use the various OC data sources independently remains an asset for resolving temporal and spatial variability
Page 26GlobColour/Medspiration User consultation – November 20-22, 2007, Oslo All rights reserved © 2006, ACRI-ST Thank you for your attention