An alternative method for correcting fluorescence quenching
Under high light intensity, phytoplankton protect their photosystems from bleaching through non-photochemical quenching processes. The consequence of this is suppression of fluorescence emission, which must be corrected when measuring in situ yield with fluorometers. We present data from the Souther...
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ftcopernicus:oai:publications.copernicus.org:os25010 2023-05-15T16:05:43+02:00 An alternative method for correcting fluorescence quenching Biermann, L. Guinet, C. Bester, M. Brierley, A. Boehme, L. 2018-01-15 application/pdf https://doi.org/10.5194/os-11-83-2015 https://os.copernicus.org/articles/11/83/2015/ eng eng doi:10.5194/os-11-83-2015 https://os.copernicus.org/articles/11/83/2015/ eISSN: 1812-0792 Text 2018 ftcopernicus https://doi.org/10.5194/os-11-83-2015 2020-07-20T16:24:48Z Under high light intensity, phytoplankton protect their photosystems from bleaching through non-photochemical quenching processes. The consequence of this is suppression of fluorescence emission, which must be corrected when measuring in situ yield with fluorometers. We present data from the Southern Ocean, collected over five austral summers by 19 southern elephant seals tagged with fluorometers. Conventionally, fluorescence data collected during the day (quenched) were corrected using the limit of the mixed layer, assuming that phytoplankton are uniformly mixed from the surface to this depth. However, distinct deep fluorescence maxima were measured in approximately 30% of the night (unquenched) data. To account for the evidence that chlorophyll is not uniformly mixed in the upper layer, we propose correcting from the limit of the euphotic zone, defined as the depth at which photosynthetically available radiation is ~ 1% of the surface value. Mixed layer depth exceeded euphotic depth over 80% of the time. Under these conditions, quenching was corrected from the depth of the remotely derived euphotic zone Z eu , and compared with fluorescence corrected from the depth of the density-derived mixed layer. Deep fluorescence maxima were evident in only 10% of the day data when correcting from mixed layer depth. This was doubled to 21% when correcting from Z eu , more closely matching the unquenched (night) data. Furthermore, correcting from Z eu served to conserve non-uniform chlorophyll features found between the 1% light level and mixed layer depth. Text Elephant Seals Southern Elephant Seals Southern Ocean Copernicus Publications: E-Journals Austral Southern Ocean Ocean Science 11 1 83 91 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
Under high light intensity, phytoplankton protect their photosystems from bleaching through non-photochemical quenching processes. The consequence of this is suppression of fluorescence emission, which must be corrected when measuring in situ yield with fluorometers. We present data from the Southern Ocean, collected over five austral summers by 19 southern elephant seals tagged with fluorometers. Conventionally, fluorescence data collected during the day (quenched) were corrected using the limit of the mixed layer, assuming that phytoplankton are uniformly mixed from the surface to this depth. However, distinct deep fluorescence maxima were measured in approximately 30% of the night (unquenched) data. To account for the evidence that chlorophyll is not uniformly mixed in the upper layer, we propose correcting from the limit of the euphotic zone, defined as the depth at which photosynthetically available radiation is ~ 1% of the surface value. Mixed layer depth exceeded euphotic depth over 80% of the time. Under these conditions, quenching was corrected from the depth of the remotely derived euphotic zone Z eu , and compared with fluorescence corrected from the depth of the density-derived mixed layer. Deep fluorescence maxima were evident in only 10% of the day data when correcting from mixed layer depth. This was doubled to 21% when correcting from Z eu , more closely matching the unquenched (night) data. Furthermore, correcting from Z eu served to conserve non-uniform chlorophyll features found between the 1% light level and mixed layer depth. |
format |
Text |
author |
Biermann, L. Guinet, C. Bester, M. Brierley, A. Boehme, L. |
spellingShingle |
Biermann, L. Guinet, C. Bester, M. Brierley, A. Boehme, L. An alternative method for correcting fluorescence quenching |
author_facet |
Biermann, L. Guinet, C. Bester, M. Brierley, A. Boehme, L. |
author_sort |
Biermann, L. |
title |
An alternative method for correcting fluorescence quenching |
title_short |
An alternative method for correcting fluorescence quenching |
title_full |
An alternative method for correcting fluorescence quenching |
title_fullStr |
An alternative method for correcting fluorescence quenching |
title_full_unstemmed |
An alternative method for correcting fluorescence quenching |
title_sort |
alternative method for correcting fluorescence quenching |
publishDate |
2018 |
url |
https://doi.org/10.5194/os-11-83-2015 https://os.copernicus.org/articles/11/83/2015/ |
geographic |
Austral Southern Ocean |
geographic_facet |
Austral Southern Ocean |
genre |
Elephant Seals Southern Elephant Seals Southern Ocean |
genre_facet |
Elephant Seals Southern Elephant Seals Southern Ocean |
op_source |
eISSN: 1812-0792 |
op_relation |
doi:10.5194/os-11-83-2015 https://os.copernicus.org/articles/11/83/2015/ |
op_doi |
https://doi.org/10.5194/os-11-83-2015 |
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Ocean Science |
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11 |
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1 |
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83 |
op_container_end_page |
91 |
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1766401617364516864 |