Constraining the Particle Size Distribution of Large Marine Particles in the Global Ocean With In Situ Optical Observations and Supervised Learning

Type : ACL
Nature : Production scientifique
Au bénéfice du Laboratoire : Oui
Statut de publication : Publié
Année de publication : 2022
Auteurs (7) : CLEMENTS Daniel,j YANG Shouye WEBER Thomas MCDONNELL A,m,p KIKO Rainer STEMMANN Lars BIANCHI Daniele
Revue scientifique : Global Biogeochemical Cycles
Volume : 36
Fascicule : 5
Pages :
DOI : 10.1029/2021GB007276
URL : https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021GB007276
Abstract : The abundance and size distribution of marine particles control a range of biogeochemical and ecological processes in the ocean, including carbon sequestration. These quantities are the result of complex physical-biological interactions that are difficult to observe, and their spatial and temporal patterns remain uncertain. Here, we present a novel analysis of particle size distributions (PSDs) from a global compilation of in situ Underwater Vision Profiler 5 (UVP5) optical measurements. Using a machine learning algorithm, we extrapolate sparse UVP5 observations to the global ocean from well-sampled oceanographic variables. We reconstruct global maps of PSD parameters (biovolume [BV] and slope) for particles at the base of the euphotic zone. These reconstructions reveal consistent global patterns, with high chlorophyll regions generally characterized by high particle BV and flatter PSD slope, that is, a high relative abundance of large versus small particles. The resulting negative correlations between particle BV and slope further suggests synergistic effects on size-dependent processes such as sinking particle fluxes. Our approach and estimates provide a baseline for an improved understanding of particle cycles in the ocean, and pave the way to global, three-dimensional reconstructions of PSD and sinking particle fluxes from the growing body of UVP5 observations.
Mots-clés : CARBON EXPORT; carbon export; FLUX; global carbon cycle; machine learning; MODEL; particulate organic matter; PHYTOPLANKTON; PLANKTON; REMINERALIZATION; remote sensing; SATELLITE; SPECTRA; SYSTEM; UNDERWATER VISION PROFILER
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Citation :
Clements DJ, Yang S, Weber T, McDonnell AMP, Kiko R, Stemmann L, Bianchi D (2022) Constraining the Particle Size Distribution of Large Marine Particles in the Global Ocean With In Situ Optical Observations and Supervised Learning. Global Biogeochem Cy 36 | doi: 10.1029/2021GB007276