Synergistic Exploitation of Hyper-and Multispectral Sentinel-Measurements to Determine Phytoplankton Functional Types (PFT) at Best Spatial and Temporal Resolution

To overcome the short-comings of current multi-spectral PFT products (supplying either knowledge on dominant groups or size fractions only, data products with strong linkage to a-priori-information) and PhytoDOAS data products (with only low temporal and spatial coverage), the project's objective is a substantial improvement of retrieving phytoplankton groups with defined accuracy and good spatial and temporal coverage. This shall be done by developing a synergistic product which contains the Chl-a (biomass) of several PFT by using complementary information from multi- and hyper-spectral satellite ocean colour data. This algorithm can be later applied to produce a synergistic PFT product from TROPOMI (on Sentinel-5-Precursor, Sentinel-4, Sentinel-5) and OLCI (on Sentinel-3).

To enlarge the coverage and to reduce the uncertainty of the PFTs and total Chl-a satellite products, as a Sentinel for SCIence Synergy Research and Development (SY-4SCI Synergy R & D) study focusing on PFTs, we

• review available PFT algorithms based on hyper- and multi-spectral datasets;
• develop an improved PFT algorithm by the synergistic use of low spatial resolution hyper-spectral data (i.e. SCIAMACHY) with high spatial multi-spectral data (i.e. MERIS).
• perform a sensitivity study, based on radiative transfer calculations, to determine the band-set needed by multi-spectral instruments (e.g. OLCI) to retrieve PFTs based on hyper-spectral data (now SCIAMACHY, future TROPOMI) PFT algorithms
• provide a scientific roadmap for future Chl-a and PFT retrievals from ocean colour (multi- and / or hyper-spectral) data

Project duration: Dec 2014 to Nov 2016

Funding: ESRIN/ESA within the SEOM (Sceintific Exploration of operational missions) - Sentinel for Science Synergy (SY-4Sci Synergy)" programme.

Consortium:

AWI, Phytooptics Group, Bremerhaven, Germany (PI: Prof. Dr. A. Bracher)

IUP, University Bremen, Bremen, Germany (Co-I: Dr. M. Vountas)

Laboratoire d’Océanographie de Villefranche (LOV), Villefranche, France (Co-I: Dr. Annick Bricaud)

Plymouth Marine Laboratory (PML), Plymouth, United Kingdom (Co-I: Dr. Robert Brewin)

Collaboration:

University of Hokkaido, Faculty of Environmental Earth Science, Sapporo, Japan (Prof. Dr. Takafumi Hirata)

AWI, Polar Biological Oceanography, Bremerhaven, Germany (Dr. Ilka Peeken)

Richmond School of Arts and Science, Dep. of Geography and Environment (Dr. Tihomir Kostadinov)