title: Particle backscattering as a function of chlorophyll and phytoplankton size structure in the open-ocean.
abstract: Using an extensive database of in situ observations we present a model that estimates the particle backscattering coefficient as a function of the total chlorophyll concentration in the open-ocean (Case-1 waters). The parameters of the model include a constant background component and the chlorophyll-specific backscattering coefficients associated with small (<20 μm) and large (>20 μm) phytoplankton. The new model performed with similar accuracy when compared with a traditional power-law function, with the additional benefit of providing information on the role of phytoplankton size. The observed spectral-dependency (γ) of model parameters was consistent with past observations, such that γ associated with the small phytoplankton population was higher than that of large phytoplankton. Furthermore, γ associated with the constant background component suggests this component is likely attributed to submicron particles. We envisage that the model would be useful for improving Case-1 ocean-colour models, assimilating light into multi-phytoplankton ecosystem models and improving estimates of phytoplankton size structure from remote sensing.
authors.affiliation: Plymouth Marine Laboratory (PML), Prospect Place, The Hoe, Plymouth PL1 3DH, UK. robr@pml.ac.uk
authors.forename: Robert J W
authors.initials: RJ
authors.lastname: Brewin
authors.forename: Giorgio
authors.initials: G
authors.lastname: Dall'Olmo
authors.forename: Shubha
authors.initials: S
authors.lastname: Sathyendranath
authors.forename: Nick J
authors.initials: NJ
authors.lastname: Hardman-Mountford
mesh_terms: D002734:Chlorophyll / Q000378:metabolism*; D019992:Databases as Topic; D005843:Geography; D008954:Models, Biological; D009792:Oceans and Seas; D010839:Phytoplankton / Q000166:cytology*; D015203:Reproducibility of Results; D012542:Scattering, Radiation
chemical_list: D002734:Chlorophyll