Correction and Accuracy of High- and Low-Resolution CTD Data from Animal-Borne Instruments
Most available CTD Satellite Relay Data Logger (CTD-SRDL) profiles are heavily compressed before satellite transmission. High-resolution profiles recorded at the sampling frequency of 0.5 Hz are, however, available upon physical retrieval of the logger. Between 2014 and 2018, several loggers deploye...
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ftarchimer:oai:archimer.ifremer.fr:60567 2023-05-15T16:05:43+02:00 Correction and Accuracy of High- and Low-Resolution CTD Data from Animal-Borne Instruments Siegelman, Lia Roquet, Fabien Mensah, Vigan Riviere, Pascal Pauthenet, Etienne Picard, Baptiste Guinet, Christophe 2019-05 application/pdf https://archimer.ifremer.fr/doc/00494/60567/64043.pdf https://archimer.ifremer.fr/doc/00494/60567/64044.pdf https://doi.org/10.1175/JTECH-D-18-0170.1 https://archimer.ifremer.fr/doc/00494/60567/ eng eng Amer Meteorological Soc https://archimer.ifremer.fr/doc/00494/60567/64043.pdf https://archimer.ifremer.fr/doc/00494/60567/64044.pdf doi:10.1175/JTECH-D-18-0170.1 https://archimer.ifremer.fr/doc/00494/60567/ info:eu-repo/semantics/openAccess restricted use Journal Of Atmospheric And Oceanic Technology (0739-0572) (Amer Meteorological Soc), 2019-05 , Vol. 36 , N. 5 , P. 745-760 Algorithms Data processing In situ oceanic observations text Publication info:eu-repo/semantics/article 2019 ftarchimer https://doi.org/10.1175/JTECH-D-18-0170.1 2021-09-23T20:32:41Z Most available CTD Satellite Relay Data Logger (CTD-SRDL) profiles are heavily compressed before satellite transmission. High-resolution profiles recorded at the sampling frequency of 0.5 Hz are, however, available upon physical retrieval of the logger. Between 2014 and 2018, several loggers deployed on elephant seals in the Southern Ocean have been set in continuous recording mode, capturing both the ascent and descent for over 60 profiles per day during several months, opening new horizons for the physical oceanography community. Taking advantage of a new dataset made of seven such loggers, a postprocessing procedure is proposed and validated to improve the quality of all CTD-SRDL data: that is, both high-resolution profiles and compressed low-resolution ones. First, temperature and conductivity are corrected for a thermal mass effect. Then salinity spiking and density inversion are removed by adjusting salinity while leaving temperature unchanged. This method, applied here to more than 50 000 profiles, yields significant and systematic improvements in both temperature and salinity, particularly in regions of rapid temperature variation. The continuous high-resolution dataset is then used to provide updated accuracy estimates of CTD-SRDL data. For high-resolution data, accuracies are estimated to be of +/- 0.02 degrees C for temperature and +/- 0.03 g kg(-1) for salinity. For low-resolution data, transmitted data points have similar accuracies; however, reconstructed temperature profiles have a reduced accuracy associated with the vertical interpolation of +/- 0.04 degrees C and a nearly unchanged salinity accuracy of +/- 0.03 g kg(-1). Article in Journal/Newspaper Elephant Seals Southern Ocean Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Southern Ocean Journal of Atmospheric and Oceanic Technology 36 5 745 760 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
topic |
Algorithms Data processing In situ oceanic observations |
spellingShingle |
Algorithms Data processing In situ oceanic observations Siegelman, Lia Roquet, Fabien Mensah, Vigan Riviere, Pascal Pauthenet, Etienne Picard, Baptiste Guinet, Christophe Correction and Accuracy of High- and Low-Resolution CTD Data from Animal-Borne Instruments |
topic_facet |
Algorithms Data processing In situ oceanic observations |
description |
Most available CTD Satellite Relay Data Logger (CTD-SRDL) profiles are heavily compressed before satellite transmission. High-resolution profiles recorded at the sampling frequency of 0.5 Hz are, however, available upon physical retrieval of the logger. Between 2014 and 2018, several loggers deployed on elephant seals in the Southern Ocean have been set in continuous recording mode, capturing both the ascent and descent for over 60 profiles per day during several months, opening new horizons for the physical oceanography community. Taking advantage of a new dataset made of seven such loggers, a postprocessing procedure is proposed and validated to improve the quality of all CTD-SRDL data: that is, both high-resolution profiles and compressed low-resolution ones. First, temperature and conductivity are corrected for a thermal mass effect. Then salinity spiking and density inversion are removed by adjusting salinity while leaving temperature unchanged. This method, applied here to more than 50 000 profiles, yields significant and systematic improvements in both temperature and salinity, particularly in regions of rapid temperature variation. The continuous high-resolution dataset is then used to provide updated accuracy estimates of CTD-SRDL data. For high-resolution data, accuracies are estimated to be of +/- 0.02 degrees C for temperature and +/- 0.03 g kg(-1) for salinity. For low-resolution data, transmitted data points have similar accuracies; however, reconstructed temperature profiles have a reduced accuracy associated with the vertical interpolation of +/- 0.04 degrees C and a nearly unchanged salinity accuracy of +/- 0.03 g kg(-1). |
format |
Article in Journal/Newspaper |
author |
Siegelman, Lia Roquet, Fabien Mensah, Vigan Riviere, Pascal Pauthenet, Etienne Picard, Baptiste Guinet, Christophe |
author_facet |
Siegelman, Lia Roquet, Fabien Mensah, Vigan Riviere, Pascal Pauthenet, Etienne Picard, Baptiste Guinet, Christophe |
author_sort |
Siegelman, Lia |
title |
Correction and Accuracy of High- and Low-Resolution CTD Data from Animal-Borne Instruments |
title_short |
Correction and Accuracy of High- and Low-Resolution CTD Data from Animal-Borne Instruments |
title_full |
Correction and Accuracy of High- and Low-Resolution CTD Data from Animal-Borne Instruments |
title_fullStr |
Correction and Accuracy of High- and Low-Resolution CTD Data from Animal-Borne Instruments |
title_full_unstemmed |
Correction and Accuracy of High- and Low-Resolution CTD Data from Animal-Borne Instruments |
title_sort |
correction and accuracy of high- and low-resolution ctd data from animal-borne instruments |
publisher |
Amer Meteorological Soc |
publishDate |
2019 |
url |
https://archimer.ifremer.fr/doc/00494/60567/64043.pdf https://archimer.ifremer.fr/doc/00494/60567/64044.pdf https://doi.org/10.1175/JTECH-D-18-0170.1 https://archimer.ifremer.fr/doc/00494/60567/ |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Elephant Seals Southern Ocean |
genre_facet |
Elephant Seals Southern Ocean |
op_source |
Journal Of Atmospheric And Oceanic Technology (0739-0572) (Amer Meteorological Soc), 2019-05 , Vol. 36 , N. 5 , P. 745-760 |
op_relation |
https://archimer.ifremer.fr/doc/00494/60567/64043.pdf https://archimer.ifremer.fr/doc/00494/60567/64044.pdf doi:10.1175/JTECH-D-18-0170.1 https://archimer.ifremer.fr/doc/00494/60567/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1175/JTECH-D-18-0170.1 |
container_title |
Journal of Atmospheric and Oceanic Technology |
container_volume |
36 |
container_issue |
5 |
container_start_page |
745 |
op_container_end_page |
760 |
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1766401624963547136 |