Effect of phytoplankton size classes on bio-optical properties of phytoplankton in the Western Iberian coast: Application of models

REMOTE SENSING OF ENVIRONMENT

卷:156

Article

Brito, Ana C.^1,2,3  Sa, Carolina¹  Brotas, Vanda^1,2,3  Brewin, Robert J. W.³  Silva, Teresa¹  Vitorino, Joao⁴  Platt, Trevor³  Sathyendranath, Shubha³ 

[1] Univ Lisbon, Fac Ciencias, Ctr Oceanog, CO FCUL, P-1749016 Lisbon, Portugal

[2] Univ Lisbon, Fac Ciencias, MARE Marine & Environm Sci Ctr, P-1749016 Lisbon, Portugal

[3] Plymouth Marine Lab, Plymouth PL1 3DH, Devon, England

[4] IH, P-1249093 Lisbon, Portugal

关键词: Remote sensing;    Phytoplankton size classes;    Ocean colour;    Pigments;    Chlorophyll-a;    Western Iberian coast;   

DOI  :  10.1016/j.rse.2014.10.020

来源: Elsevier

【 摘 要 】

Chlorophyll-a satellite products are routinely used in oceanography, providing a synoptic and global view of phytoplankton abundance. However, these products lack information on the community structure of the phytoplankton, which is crucial for ecological modelling and ecosystem studies. To assess the usefulness of existing methods to differentiate phytoplankton functional types (PFT) or phytoplankton size classes from satellite data, in-situ phytoplankton samples collected in the Western Iberian coast, on the North-East Atlantic, were analysed for pigments and absorption spectra. Water samples were collected in five different locations, four of which were located near the shore and another in an open-ocean, seamount region. Three different modelling approaches for deriving phytoplankton size classes were applied to the in situ data. Approaches tested provide phytoplankton size class information based on the input of pigments data (Brewin et al., 2010), absorption spectra data (Ciotti et al., 2002) or both (Uitz et al., 2008). Following Uitz et al. (2008), results revealed high variability in microphytoplankton chlorophyll-specific absorption coefficients, ranging from 0.01 to 0.09 m(2) (mg chl)(-1) between 400 and 500 nm. This spectral analysis suggested, in one of the regions, the existence of small cells (<20 mu m) in the fraction of phytoplankton presumed to be microphytoplankton (based on diagnostic pigments). Ciotti et al. (2002) approach yielded the highest differences between modelled and measured absorption spectra for the locations where samples had high variability in community structure and cell size. The Brewin et al. (2010) pigment-based model was adjusted and a set of model coefficients are presented and recommended for future studies in offshore water of the Western Iberian coast. (C) 2014 Elsevier Inc. All rights reserved.

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