FN Archimer Export Format PT J TI Neural Network Approaches to Reconstruct Phytoplankton Time-Series in the Global Ocean BT AF Martinez, Elodie Brini, Anouar Gorgues, Thomas Drumetz, Lucas Roussillon, Joana Tandeo, Pierre Maze, Guillaume Fablet, Ronan AS 1:3;2:3;3:3;4:2;5:3;6:2;7:1;8:2; FF 1:;2:;3:;4:;5:;6:;7:PDG-ODE-LOPS-OH;8:; C1 Laboratoire d’Océanographie Physique et Spatiale (LOPS), IUEM, University Brest-CNRS-IRD-Ifremer, 29200 Brest, France IMT Atlantique, Lab-STICC, UMR CNRS 6285, 29200 Brest, France Laboratoire d’Océanographie Physique et Spatiale (LOPS), IUEM, University Brest-CNRS-IRD-Ifremer, 29200 Brest, France C2 IFREMER, FRANCE IMT ATLANTIQUE, FRANCE IRD, FRANCE SI BREST SE PDG-ODE-LOPS-OH UM LOPS IN WOS Ifremer UMR WOS Cotutelle UMR DOAJ copubli-france copubli-p187 IF 2.1 TC 5 UR https://archimer.ifremer.fr/doc/00667/77871/80017.pdf https://archimer.ifremer.fr/doc/00667/77871/80018.pdf https://archimer.ifremer.fr/doc/00667/77871/97543.pdf LA English DT Article DE ;phytoplankton time-series reconstruction;ocean color;neural networks;support vector regression;multi-layer perceptron;physical predictors AB Phytoplankton plays a key role in the carbon cycle and supports the oceanic food web. While its seasonal and interannual cycles are rather well characterized owing to the modern satellite ocean color era, its longer time variability remains largely unknown due to the short time-period covered by observations on a global scale. With the aim of reconstructing this longer-term phytoplankton variability, a support vector regression (SVR) approach was recently considered to derive surface Chlorophyll-a concentration (Chl, a proxy of phytoplankton biomass) from physical oceanic model outputs and atmospheric reanalysis. However, those early efforts relied on one particular algorithm, putting aside the question of whether different algorithms may have specific behaviors. Here, we show that this approach can also be applied on satellite observations and can even be further improved by testing performances of different machine learning algorithms, the SVR and a neural network with dense layers (a multi-layer perceptron, MLP). The MLP outperforms the SVR to capture satellite Chl (correlation of 0.6 vs. 0.17 on a global scale, respectively) along with its seasonal and interannual variability, despite an underestimated amplitude. Among deep learning algorithms, neural network such as MLP models appear to be promising tools to investigate phytoplankton long-term time-series. PY 2020 PD DEC SO Remote Sensing SN 2072-4292 PU MDPI AG VL 12 IS 24 UT 000603329000001 DI 10.3390/rs12244156 ID 77871 ER EF