Automatic Detection of Optical Signatures within and around Floating Tonga-Fiji Pumice Rafts Using MODIS, VIIRS, and OLCI Satellite Sensors
| Autor: | Christophe E. Menkès, Robert Frouin, Andra Whiteside, Awnesh M. Singh, Cécile Dupouy, Jérôme Lefèvre |
|---|---|
| Přispěvatelé: | Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Ecologie marine tropicale des océans Pacifique et Indien (ENTROPIE [Nouvelle-Calédonie]), Ifremer - Nouvelle-Calédonie, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Université de la Nouvelle-Calédonie (UNC), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie]), Institut de Recherche pour le Développement (IRD [Nouvelle-Calédonie])-Ifremer - Nouvelle-Calédonie, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de la Nouvelle-Calédonie (UNC) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Visible Infrared Imaging Radiometer Suite
010504 meteorology & atmospheric sciences PIERRE PONCE 010502 geochemistry & geophysics 01 natural sciences ocean color remote sensing Tonga-Fiji pumice rafts chlorophyll-a Pumice TONGA Satellite imagery 14. Life underwater CAPTEUR lcsh:Science FIDJI ERUPTION 0105 earth and related environmental sciences TEMPERATURE DE SURFACE geography geography.geographical_feature_category DONNEES SATELLITE Pumice raft Shoal TELEDETECTION SPATIALE COULEUR DE L'OCEAN CHLOROPHYLLE CHLOROPHYLLE A Sea surface temperature Oceanography VOLCAN 13. Climate action Ocean color [SDU]Sciences of the Universe [physics] General Earth and Planetary Sciences lcsh:Q Moderate-resolution imaging spectroradiometer [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing Geology |
| Zdroj: | Remote Sensing Remote Sensing, MDPI, 2021, 13 (3), 507 [15 p. en ligne]. ⟨10.3390/rs13030501⟩ Remote Sensing, Vol 13, Iss 501, p 501 (2021) Remote Sensing, 2021, 13 (3), 507 [15 p. en ligne]. ⟨10.3390/rs13030501⟩ Remote Sensing (2072-4292) (Mdpi), 2021-02, Vol. 13, N. 3, P. 501 (15p.) Remote Sensing; Volume 13; Issue 3; Pages: 501 |
| ISSN: | 2072-4292 |
| DOI: | 10.3390/rs13030501⟩ |
| Popis: | International audience; An underwater volcanic eruption off the Vava'u island group in Tonga on 7 August 2019 resulted in the creation of floating pumice on the ocean's surface extending over an area of 150 km2. The pumice's far-reaching effects from its origin in the Tonga region to Fiji and the methods of automatic detection using satellite imagery are described, making it possible to track the westward drift of the pumice raft over 43 days. Level 2 Moderate Resolution Imaging Spectroradiometer (MODIS), Visible Infrared Imaging Radiometer Suite (VIIRS), Sentinel-3 Ocean and Land Color Instrument (OLCI), and Sentinel-3 Sea and Land Surface Temperature Radiometer (SLSTR) imagery of sea surface temperature, chlorophyll-a concentration, quasi-surface (i.e., Rayleigh-corrected) reflectance,and remote sensing reflectance were used to distinguish consolidated and fragmented rafts as well as discolored and mesotrophic waters. The rafts were detected by a 1 to 3.5°C enhancement in the MODIS-derived "sea surface temperature" due to the emissivity difference of the raft material. Large plumes of discolored waters, characterized by higher satellite reflectance/backscattering of particles in the blue than surrounding waters (and corresponding to either submersed pumice or associated white minerals), were associated with the rafts. The discolored waters had relatively lower chlorophyll-a concentration, but this was artificial, resulting from the higher blue/red reflectance ratio caused by the reflective pumice particles. Mesotrophic waters were scarce in the region of the pumice rafts, presumably due to the absence of phytoplanktonic response to a silicium-rich pumice environment in these tropical oligotrophic environments. As beach accumulations around Pacific islands surrounded by coral shoals are a recurrent phenomenon that finds its origin far east in the ocean along the Tongan trench, monitoring the events from space, as demonstrated for the 7 August 2019 eruption, might help mitigate their potential economic impacts. |
| Databáze: | OpenAIRE |
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