Improved accuracy and spatial resolution for bio-logging-derived chlorophyll a fluorescence measurements in the Southern Ocean
The ocean’s meso- and submeso-scales (1-100 km, days to weeks) host features like filaments and eddies that have a key structuring effect on phytoplankton distribution, but that due to their ephemeral nature, are challenging to observe. This problem is exacerbated in regions with heavy cloud coverag...
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Online Access: | http://dx.doi.org/10.3389/fmars.2023.1122822 https://www.frontiersin.org/articles/10.3389/fmars.2023.1122822/full |
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crfrontiers:10.3389/fmars.2023.1122822 2024-05-12T08:03:12+00:00 Improved accuracy and spatial resolution for bio-logging-derived chlorophyll a fluorescence measurements in the Southern Ocean Le Ster, Loïc Claustre, Hervé d’Ovidio, Francesco Nerini, David Picard, Baptiste Guinet, Christophe Centre National d’Etudes Spatiales European Research Council 2023 http://dx.doi.org/10.3389/fmars.2023.1122822 https://www.frontiersin.org/articles/10.3389/fmars.2023.1122822/full unknown Frontiers Media SA https://creativecommons.org/licenses/by/4.0/ Frontiers in Marine Science volume 10 ISSN 2296-7745 Ocean Engineering Water Science and Technology Aquatic Science Global and Planetary Change Oceanography journal-article 2023 crfrontiers https://doi.org/10.3389/fmars.2023.1122822 2024-04-18T07:56:28Z The ocean’s meso- and submeso-scales (1-100 km, days to weeks) host features like filaments and eddies that have a key structuring effect on phytoplankton distribution, but that due to their ephemeral nature, are challenging to observe. This problem is exacerbated in regions with heavy cloud coverage and/or difficult access like the Southern Ocean, where observations of phytoplankton distribution by satellite are sparse, manned campaigns costly, and automated devices limited by power consumption. Here, we address this issue by considering high-resolution in-situ data from 18 bio-logging devices deployed on southern elephant seals ( Mirounga leonina) in the Kerguelen Islands between 2018 and 2020. These devices have submesoscale-resolving capabilities of light profiles due to the high spatio-temporal frequency of the animals’ dives (on average 1.1 +-0.6 km between consecutive dives, up to 60 dives per day), but observations of fluorescence are much coarser due to power constraints. Furthermore, the chlorophyll a concentrations derived from the (uncalibrated) bio-logging devices’ fluorescence sensors lack a common benchmark to properly qualify the data and allow comparisons of observations. By proposing a method based on functional data analysis, we show that a reliable predictor of chlorophyll a concentration can be constructed from light profiles (14 686 in our study). The combined use of light profiles and matchups with satellite ocean-color data enable effective (1) homogenization then calibration of the bio-logging devices’ fluorescence data and (2) filling of the spatial gaps in coarse-grained fluorescence sampling. The developed method improves the spatial resolution of the chlorophyll a field description from ~30 km to ~12 km. These results open the way to empirical study of the coupling between physical forcing and biological response at submesoscale in the Southern Ocean, especially useful in the context of upcoming high-resolution ocean-circulation satellite missions. Article in Journal/Newspaper Elephant Seals Kerguelen Islands Mirounga leonina Southern Elephant Seals Southern Ocean Frontiers (Publisher) Southern Ocean Kerguelen Kerguelen Islands Frontiers in Marine Science 10 |
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Open Polar |
collection |
Frontiers (Publisher) |
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crfrontiers |
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topic |
Ocean Engineering Water Science and Technology Aquatic Science Global and Planetary Change Oceanography |
spellingShingle |
Ocean Engineering Water Science and Technology Aquatic Science Global and Planetary Change Oceanography Le Ster, Loïc Claustre, Hervé d’Ovidio, Francesco Nerini, David Picard, Baptiste Guinet, Christophe Improved accuracy and spatial resolution for bio-logging-derived chlorophyll a fluorescence measurements in the Southern Ocean |
topic_facet |
Ocean Engineering Water Science and Technology Aquatic Science Global and Planetary Change Oceanography |
description |
The ocean’s meso- and submeso-scales (1-100 km, days to weeks) host features like filaments and eddies that have a key structuring effect on phytoplankton distribution, but that due to their ephemeral nature, are challenging to observe. This problem is exacerbated in regions with heavy cloud coverage and/or difficult access like the Southern Ocean, where observations of phytoplankton distribution by satellite are sparse, manned campaigns costly, and automated devices limited by power consumption. Here, we address this issue by considering high-resolution in-situ data from 18 bio-logging devices deployed on southern elephant seals ( Mirounga leonina) in the Kerguelen Islands between 2018 and 2020. These devices have submesoscale-resolving capabilities of light profiles due to the high spatio-temporal frequency of the animals’ dives (on average 1.1 +-0.6 km between consecutive dives, up to 60 dives per day), but observations of fluorescence are much coarser due to power constraints. Furthermore, the chlorophyll a concentrations derived from the (uncalibrated) bio-logging devices’ fluorescence sensors lack a common benchmark to properly qualify the data and allow comparisons of observations. By proposing a method based on functional data analysis, we show that a reliable predictor of chlorophyll a concentration can be constructed from light profiles (14 686 in our study). The combined use of light profiles and matchups with satellite ocean-color data enable effective (1) homogenization then calibration of the bio-logging devices’ fluorescence data and (2) filling of the spatial gaps in coarse-grained fluorescence sampling. The developed method improves the spatial resolution of the chlorophyll a field description from ~30 km to ~12 km. These results open the way to empirical study of the coupling between physical forcing and biological response at submesoscale in the Southern Ocean, especially useful in the context of upcoming high-resolution ocean-circulation satellite missions. |
author2 |
Centre National d’Etudes Spatiales European Research Council |
format |
Article in Journal/Newspaper |
author |
Le Ster, Loïc Claustre, Hervé d’Ovidio, Francesco Nerini, David Picard, Baptiste Guinet, Christophe |
author_facet |
Le Ster, Loïc Claustre, Hervé d’Ovidio, Francesco Nerini, David Picard, Baptiste Guinet, Christophe |
author_sort |
Le Ster, Loïc |
title |
Improved accuracy and spatial resolution for bio-logging-derived chlorophyll a fluorescence measurements in the Southern Ocean |
title_short |
Improved accuracy and spatial resolution for bio-logging-derived chlorophyll a fluorescence measurements in the Southern Ocean |
title_full |
Improved accuracy and spatial resolution for bio-logging-derived chlorophyll a fluorescence measurements in the Southern Ocean |
title_fullStr |
Improved accuracy and spatial resolution for bio-logging-derived chlorophyll a fluorescence measurements in the Southern Ocean |
title_full_unstemmed |
Improved accuracy and spatial resolution for bio-logging-derived chlorophyll a fluorescence measurements in the Southern Ocean |
title_sort |
improved accuracy and spatial resolution for bio-logging-derived chlorophyll a fluorescence measurements in the southern ocean |
publisher |
Frontiers Media SA |
publishDate |
2023 |
url |
http://dx.doi.org/10.3389/fmars.2023.1122822 https://www.frontiersin.org/articles/10.3389/fmars.2023.1122822/full |
geographic |
Southern Ocean Kerguelen Kerguelen Islands |
geographic_facet |
Southern Ocean Kerguelen Kerguelen Islands |
genre |
Elephant Seals Kerguelen Islands Mirounga leonina Southern Elephant Seals Southern Ocean |
genre_facet |
Elephant Seals Kerguelen Islands Mirounga leonina Southern Elephant Seals Southern Ocean |
op_source |
Frontiers in Marine Science volume 10 ISSN 2296-7745 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3389/fmars.2023.1122822 |
container_title |
Frontiers in Marine Science |
container_volume |
10 |
_version_ |
1798845311207079936 |