title: Inherent optical properties and satellite retrieval of chlorophyll concentration in the lagoon and open ocean waters of New Caledonia.
abstract: The retrieval of chlorophyll-a concentration from remote sensing reflectance (Rrs) data was tested with the NASA OC4v4 algorithm on the inner New Caledonian lagoon (Case 2) and adjacent open ocean (Case 1) waters. The input to OC4v4 was Rrs measured in situ or modeled from water's inherent optical properties (2001-2007). At open ocean stations, backscattering and absorption coefficients were correlated with chlorophyll (R(2)=0.31-0.51, respectively), in agreement with models for Case 1 waters. Taking spectrofluorometric measurement as reference, the OC4v4 model leads to an average underestimation of 33% of the chlorophyll concentration. For the lagoon waters, OC4v4 performed inadequately because the backscattering coefficient, highly correlated with turbidity and suspended matter (R(2)=0.98), was poorly correlated to chlorophyll (R(2)=0.42). The OC4v4 performance was better in deep lagoon waters for stations with a TDT index (Tchla x depth/turbidity) higher than 19 mg m(-2) NTU(-1) (R(2)=0.974, bias=10.2%). Global Imager Rrs provided a good estimate of Tchla (R(2)=0.79, N=28) in the deeper part of the lagoon.
authors.affiliation: Université de la Méditerranée, IRD, UR Camelia, BP A5, 98848 Nouméa Cedex, New Caledonia. cecile.dupouy@ird.fr
authors.forename: Cécile
authors.initials: C
authors.lastname: Dupouy
authors.forename: Jacques
authors.initials: J
authors.lastname: Neveux
authors.forename: Sylvain
authors.initials: S
authors.lastname: Ouillon
authors.forename: Robert
authors.initials: R
authors.lastname: Frouin
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Murakami
authors.forename: Sébastien
authors.initials: S
authors.lastname: Hochard
authors.forename: Guillaume
authors.initials: G
authors.lastname: Dirberg
mesh_terms: D000465:Algorithms; D002734:Chlorophyll / Q000032:analysis*; D017753:Ecosystem; D004784:Environmental Monitoring; D009510:New Caledonia; D055620:Optical Phenomena; D010140:Pacific Ocean; D010839:Phytoplankton; D017215:Satellite Communications; D012623:Seawater / Q000032:analysis*
chemical_list: D002734:Chlorophyll