Abstract
We derive the chlorophyll a concentration (Chla) for three main phytoplankton functional types (PFTs) – diatoms, coccolithophores and cyanobacteria – by combining satellite multispectral-based information, being of a high spatial and temporal resolution, with retrievals based on high resolution of PFT absorption properties derived from hyperspectral satellite measurements. The multispectral-based PFT Chla retrievals are based on a revised version of the empirical OC-PFT algorithm applied to the Ocean Color Climate Change Initiative (OC-CCI) total Chla product. The PhytoDOAS analytical algorithm is used with some modifications to derive PFT Chla from SCIAMACHY hyperspectral measurements. To combine synergistically these two PFT products (OC-PFT and PhytoDOAS), an optimal interpolation is performed for each PFT in every OC-PFT sub-pixel within a PhytoDOAS pixel, given its Chla and its a priori error statistics. The synergistic product (SynSenPFT) is presented for the period of August 2002 March 2012 and evaluated against PFT Chla data obtained from in situ marker pigment data and the NASA Ocean Biogeochemical Model simulations and satellite information on phytoplankton size. The most challenging aspects of the SynSenPFT algorithm implementation are discussed. Perspectives on SynSenPFT product improvements and prolongation of the time series over the next decades by adaptation to Sentinel multi- and hyperspectral instruments are highlighted.
Highlights
Phytoplankton supplies over 90% of the nutrition consumed by the higher trophic levels of the marine ecosystem and contributes to 50% of the global primary production (Field et al, 1998)
We present the results of the triple collocation (TC) analysis carried out with respect to OC-phytoplankton functional types (PFT), PhytoDOAS, and NASA Ocean Biogeochemical Model (NOBM) PFT data products
The σε of PhytoDOAS coccolithophores chlorophyll “a” concentration (Chla) (Figure 4D) exceeds similar statistical estimates of NOBM coccolithophores (Figure 4F) and OC-PFT haptophytes products (Figure 4E), even in the high Northern latitudes, and the OC-PFT shows higher haptophytes Chla ranges in the Arabian Sea and upwelling regions (Figure 4E)
Summary
Phytoplankton supplies over 90% of the nutrition consumed by the higher trophic levels of the marine ecosystem and contributes to 50% of the global primary production (Field et al, 1998). It is very important for global biogeochemical fluxes (e.g., carbon) since it fixes atmospheric carbon, CO2, and produces organic carbon compounds. Diatoms are the phytoplankton silicifiers, which contribute to most of the primary production and biomass during the spring bloom in temperate and polar regions (Buesseler, 1998) Their importance is related to the efficiency of carbon export through the direct sinking of single cells, key grazing pathways and through mass sedimentation events at the end of the spring blooms when nutrients are depleted (Le Qur et al, 2005). Cyanobacteria regenerate nutrients and, influence the marine recycled production (Waterbury et al, 1986; Morán et al, 2004)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
