The assimilation of satellite absorption and glider data into novel bio-optical module coupled to ERSEM on the North-West European Shelf

Jozef Skakala, Plymouth Marine Laboratory/National Centre for Earth Observation, Plymouth, United Kingdom, Stefano Ciavatta, Plymouth Marine Laboratory, Plymouth, United Kingdom, Jorn Bruggeman, Plymouth Marine Laboratory, MEMP, Plymouth, United Kingdom, David Ford, Met Office Hadley center for Climate Change, Exeter, United Kingdom and Robert J W Brewin, College of Life and Environmental Sciences, University of Exeter, Penryn, United Kingdom
The North-West European Shelf (NWES) is a very important region for both European economy and the marine ecosystem impact on carbon cycle. We introduced a novel spectrally resolved (stand-alone) bio-optical module into the European Regional Seas Ecosystem Model (ERSEM) to improve how ERSEM represents primary productivity on the NWES. The bio-optical module also gives us the capability to provide biogeochemical feedback on physics, in particular the improved representation of under-water light field can be used to improve the temperature profiles. We used the bio-optical module to assimilate novel Phytoplankton Functional Type (PFT) absorption satellite product into the coupled NEMO-FABM-ERSEM model and we have shown that absorption data assimilation has some advantages over the currently established PFT chlorophyll-a assimilation. In particular the PFT absorption assimilation outperforms PFT chlorophyll assimilation in how it represents the under-water light field and some ecosystem indicators (ie. PFT chlorophyll-to-carbon ratios). We further implemented the bio-optical module in the context of combined assimilation of glider profiles (oxygen, total chlorophyll) and satellite data.