Open AccessRadiometric approach for the detection of picophytoplankton assemblages across oceanic fronts
Author(s) -
Priscila Kienteca Lange,
P. Jeremy Werdell,
Zachary K. Erickson,
Giorgio Dall’Olmo,
Robert J. W. Brewin,
Mikhail V. Zubkov,
Glen A. Tarran,
Heather Bouman,
Wayne Slade,
Susanne E. Craig,
Nicole Poulton,
Astrid Bracher,
Michael W. Lomas,
Ivona Cetinić
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.398127
Subject(s) - prochlorococcus , synechococcus , ocean gyre , environmental science , phytoplankton , ocean color , oceanography , argo , hyperspectral imaging , remote sensing , seawifs , deep chlorophyll maximum , transect , photic zone , satellite , geology , ecology , subtropics , cyanobacteria , biology , paleontology , aerospace engineering , nutrient , bacteria , engineering
Cell abundances of Prochlorococcus, Synechococcus, and autotrophic picoeukaryotes were estimated in surface waters using principal component analysis (PCA) of hyperspectral and multispectral remote-sensing reflectance data. This involved the development of models that employed multilinear correlations between cell abundances across the Atlantic Ocean and a combination of PCA scores and sea surface temperatures. The models retrieve high Prochlorococcus abundances in the Equatorial Convergence Zone and show their numerical dominance in oceanic gyres, with decreases in Prochlorococcus abundances towards temperate waters where Synechococcus flourishes, and an emergence of picoeukaryotes in temperate waters. Fine-scale in-situ sampling across ocean fronts provided a large dynamic range of measurements for the training dataset, which resulted in the successful detection of fine-scale Synechococcus patches. Satellite implementation of the models showed good performance (R2 > 0.50) when validated against in-situ data from six Atlantic Meridional Transect cruises. The improved relative performance of the hyperspectral models highlights the importance of future high spectral resolution satellite instruments, such as the NASA PACE mission's Ocean Color Instrument, to extend our spatiotemporal knowledge about ecologically relevant phytoplankton assemblages.