title: Multivariate approach for the retrieval of phytoplankton size structure from measured light absorption spectra in the Mediterranean Sea (BOUSSOLE site).
abstract: Models based on the multivariate partial least squares (PLS) regression technique are developed for the retrieval of phytoplankton size structure from measured light absorption spectra (BOUSSOLE site, northwestern Mediterranean Sea). PLS-models trained with data from the Mediterranean Sea showed good accuracy in retrieving, over the nine-year BOUSSOLE time series, the concentrations of total chlorophyll a [Tchl a], of the sum of seven diagnostic pigments and of pigments associated with micro, nano, and picophytoplankton size classes separately. PLS-models trained using either total particle or phytoplankton absorption spectra performed similarly, and both reproduced seasonal variations of biomass and size classes derived by high performance liquid chromatography. Satisfactory retrievals were also obtained using PLS-models trained with a data set including various locations of the world's oceans, with however a lower accuracy. These results open the way to an application of this method to absorption spectra derived from hyperspectral and field satellite radiance measurements.
authors.affiliation: Laboratoire d’Océanographie de Villefranche, UMR 7093, CNRS and Université Pierre et Marie Curie, Paris 6, France. emanuele.organelli@obs-vlfr.fr
authors.forename: Emanuele
authors.initials: E
authors.lastname: Organelli
authors.forename: Annick
authors.initials: A
authors.lastname: Bricaud
authors.forename: David
authors.initials: D
authors.lastname: Antoine
authors.forename: Julia
authors.initials: J
authors.lastname: Uitz
mesh_terms: D000465:Algorithms; D002734:Chlorophyll / Q000032:analysis*; D000077194:Chlorophyll A; D003627:Data Interpretation, Statistical; D004784:Environmental Monitoring / Q000379:methods*; D015999:Multivariate Analysis; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D010783:Photometry / Q000379:methods*; D010839:Phytoplankton / Q000166:cytology* / Q000502:physiology*; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D002734:Chlorophyll; D000077194:Chlorophyll A