Carsten Brockmann, Ana Ruescas, Simon Pinnock CoastColour Team: BC D, HZG D, PML UK, RBINS B, LISE F, FCUL P COASTCOLOUR SPOT 4 TAKE 5

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1 Carsten Brockmann, Ana Ruescas, Simon Pinnock CoastColour Team: BC D, HZG D, PML UK, RBINS B, LISE F, FCUL P COASTCOLOUR SPOT 4 TAKE 5

2 CoastColour CoastColour is providing ocean colour products for coastal areas with optimised algorithms for coastal waters Water leaving reflectances Turbidity indicators Inherent optical properties Concentrations of chlorophyll and suspended matter User require these data for Coastal monitoring Marine spatial planning Biological studies Driver for CoastColour Requirement for high spatial resolution (better than 1km and ideally 100m) Exploitation of MERIS FR data Spectral characteristics optimised for coastal applications Spatial resolution of 300m Demonstrating benefit of higher spatial resolution (SPOT4 TAKE5)

3 Products CoastColour v1 MERIS FR globally distributed sites QAA and NN based Water Quality products OWT classification Available May 2013 (ftp) CoastColour v2 Merged NN & OC4 in-water algorithm MERIS FR & RR TB input data Complete global coverage On-demand processing Online since

4 On-Demand Processing

5 Preparing for S2 SPOT4 TAKE5 Chesapeak Bay Korean Coast

6 High Resolution Study Sites Chesapeak Bay Optically complex waters 3 different regimes within the bay Eutrophic, mesotrophic, oceanic Cooperation with NASA US standard coastal site Long time series Korean Coast Highly turbid water Dry fallen intertidal flats Important coastal areas Fishing vs Environmental protection Cooperation with KORDI GOCI Geostationaly Ocean Colour Imager

7 High Resolution Study Demonstrating the potential of spatial high resolution EO data for coastal ocean colour applications Preparing for Sentinel 2 Spatial resolution 100m or better Spectral characteristics of Sentinel 2: not a dedicated ocean colour instrument but spectral bands have the potential to provide good turbidity, TSM and possibly roughly Chl retrievals. This includes bands for marine atmospheric correction SPOT 4 TAKE 5 Data SPOT 4 Sentinel 2 orbit, but less favourable spectral bands Rapid Eye complementing the SPOT dataset Landsat 8 closer to Sentinel 2 spectral bands Approach and Challenges (Rough) Atmospheric correction Single band TSM algorithm Intercalibration with MODIS

8 Sentinel 2 Spectral and Radiometric Characteristics IOPs IOPs AC SPOT4 AC (very turbid waters) IOPs Cloud/Snow/Ice Screening

9 SPOT 4 Take 5 REFLECTANCES

10 Approach

11 Landsat and CC-turbidity

12 TSM METHODOLOGY Approach developed by Nechad et al to XS2 ( nm) S= AApp pp ww + BB pp SPOT-TSM= XXXXX 1 ppww 1 XXXXX CC pp Comparison of SPOT-TSM (x) and the MODIS TSM (y) in bands 645, 667 and 678 nm (blue, red and green respectively) on

13 SPOT-MODIS PAIRS Chesapeake Conditions Korea Conditions MODIS SPOT MODIS SPOT good good cloudy good moderate glint cloudy glint good glint cloudy glint

14 SPOT_RGB TSM SPOT-MODIS Chesapeake Bay SPOT_RGB SPOT_RGB SPOT_TSM_Nechad (20 m) SPOT_TSM_Nechad (20 m) SPOT_TSM_Nechad (20 m) MODIS_Nechad_678 (1 km) MODIS_Nechad_678 (1 km) MODIS_Nechad_678 (1km)

15 Benefits Demonstration of resolution of spatial pattern Simple TSM algorithm provides realistic estimates Sentinel 2 orbit and repetition rate provide improved temporal coverage In the framework of FP7 HighRoc project, Vanhellemont & Ruddick showed the potential to resolve the impact of a windpark on the local TSM field with Landsat-8 (shown on Monday)

16 S2 Offshore Application: Environmental Impact Assessment Environmental Impacts Assessment legal obligation for offshore wind farm construction LANDSA T-8 and S-2 high spatial resolution => new Environmental Impacts visible Sediment wakes in direction of tidal current [(c) RBINS, J-P. Vogt] [Vanhellemont & Ruddick K (2014). Turbid wakes associated with offshore wind turbines observed with Landsat 8. Remote Sensing of Environment, 145, pp Open Access]

17 ERRORS AND LIMITATIONS LIMITATIONS Lack of in situ data for comparison, calibration and validation activities Cloud cover High glint areas Viewing conditions SOURCES OF ERRORS Atmospheric correction related errors Adjacency effect not corrected Mixed pixels not flagged Bottom reflection Difference in viewing conditions (validation) Time differences (validation)

18 Towards Sentinel 2 Application of Landsat 8 for coastal studies FP7 HighRoc Project Valuable information products for coastal and inland waters Not a pre-cursor but 1 st sensor for a merged S2+L8 product Preprocessing needs improvement for spatial high resolution data Cloud screening, cloud shadow Sea Ice Development of a dedicated coastal water atmospheric correction for S2 CoastColour NN-AC adaption is currently under development and will be investigated Adjacency effect correction needs consolidation Study possibilities to resolve variability of global coastal water optical properties with S2 On-demand processing is a good option Offer all available input data Processing and storing of large data quantities only if needed Offer regional algorithms Coastal Thematic Exploitation Platform

19 On-Demand Processing

20 Acknowledgement We would like to acknowledge each one of the PIs contributing with valuable data to the CoastColour in-situ and Mermaid databases: G. Zibordi, J.Icely, J.F. Berthon, E. Canuti, D. Antoine, D. McKee, H. Klein, G. Mitchell, M. Kahru, S.B. Mustapha, S. Belanger, M. Ondrusek, G, Schuster, B. Holben, H. Loisel, R. Doerffer, A. Gilerson, S. Ahmed, V. bando, C. Belin, K, Voss, K.Hughes, K, Ruddick, H. Sosik, H. Feng, N. Nelson, A. Subramaniam, L.Harding, A.Mannino, R. Gould, R. Arnone, S.Hooker, W.Balch, R. Morrison, K.Carder, F. Muller-Karger, J. Werdell, D. Stramski, D. Siegel, G. Mitchell, Z. Lee, S. Kratzer, G. Tilstone, V. Brotas, P.Y. Deschamps, A. Hommersom, A. Weidemann, B. Gibson, as well as ACRI-ST, ARGANS and ESA for access to the MERMAID system (