OPTICAL DATA MODELLING AND ASSIMILATION
PI and organization: S. Ciavatta (PML)
Co-Is: R. Brewin (PML), J. Skakala (PML), B. Taylor (PML), T. Smyth (NERC/PML), J. Bruggeman (PML), D. Ford (UK MetOffice)
OPTIMA advanced the potenitial capability of CMEMS to accurately assess and predict the state of the marine environment, by developing the first system assimilating spectral absorption of phytoplankton functional types (PFT) from ocean colour, into the CMEMS MFC North West Shelf model. The main project achievements were:
1. The development of an ocean-colour PFT spectral absorption algorithm for diatoms, dinoflagellates, nanophytoplankton and picophytoplankton, at twelve wavelengths; this algorithm was skilled in estimating in situ spectral absorption data of the PFTs in the CMEMS Atlantic region (ATL);
2. The delivery of ~20 years long time series of daily data of spectral absorption of the 4 PFTs in the CMEMS ATL region, at twelve wavelengths, at 4 km resolution, spanning the years 1997- 2015. For the first time, per-pixel error estimates were provided along with the PFT absorption data;
3. The development of a portable spectral radiative and bio-optical modules, which can be used with the NEMO-ERSEM model of the CMEMS MFC NWS, as well as with other hydrodynamic and PFT models interfaced with FABM. The model was corroborated with atmospheric and water column optical data in a 1-dimensional configuration for the long term-monitoring station L4 (GOTM-ERSEM) ;
4. The implementation and validation of the spectral radiative module into the CMEMS MFC NWS configuration for NEMO-FABM-ERSEM followed by the improved assimilative capacity of NEMOVAR that now includes assimilation of the spectrally resolved PFT absorption;
5. The delivery of quality assessed 1-year reanalysis assimilating PFT absorption (and also PFT chlorophyll) into NEMO-FABM-ERSEM using the spectrally resolved module.
The project clearly demonstrated that a) the bio-optical module on its own improves the simulation of underwater light field, b) the assimilation of PFT absorption further improves the simulated underwater light field and also model biogeochemistry.
OPTIMA is the object of 1 published paper, 1 manuscript under review and 1 manuscript in preparation with submission expected in Spring 2020 and the results were disseminated in 11 conferences.