Two-component modeling of the optical properties of a diatom bloom in the Southern ocean
Diatom cells have distinctive optical characteristics, originating from their relatively large cell size, fucoxanthin content and silica cell wall. It has been proposed that diatom-dominated phytoplankton blooms can be identified by optical remote sensing and that specifically tuned chlorophyll and...
Published in: | Remote Sensing of Environment |
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ftnerc:oai:nora.nerc.ac.uk:14494 2023-05-15T18:25:52+02:00 Two-component modeling of the optical properties of a diatom bloom in the Southern ocean Cunningham, Alex Carrie, Iain D. Korb, Rebecca E. 2011 http://nora.nerc.ac.uk/id/eprint/14494/ unknown Elsevier Cunningham, Alex; Carrie, Iain D.; Korb, Rebecca E. 2011 Two-component modeling of the optical properties of a diatom bloom in the Southern ocean. Remote Sensing of Environment, 115 (6). 1434-1442. https://doi.org/10.1016/j.rse.2011.01.023 <https://doi.org/10.1016/j.rse.2011.01.023> Marine Sciences Biology and Microbiology Electronics Engineering and Technology Publication - Article PeerReviewed 2011 ftnerc https://doi.org/10.1016/j.rse.2011.01.023 2023-02-04T19:29:14Z Diatom cells have distinctive optical characteristics, originating from their relatively large cell size, fucoxanthin content and silica cell wall. It has been proposed that diatom-dominated phytoplankton blooms can be identified by optical remote sensing and that specifically tuned chlorophyll and primary production algorithms should be applied in regions where these blooms are present. However there have been few studies on how the optical properties of diatom blooms change as they progress from active growth to senescence, and it is unlikely that measurements on laboratory cultures encompass the full range of physiological states found in natural waters. We have therefore examined the inherent optical properties (IOPs) of the waters around the island of South Georgia at the end of the spring diatom bloom. Considerable variability was found in the relationships between the inherent optical properties and analytically determined chlorophyll a concentrations even in the surface layer, which meant that the usual bio-optical assumptions for Case 1 waters did not apply. To account for this variability, phytoplankton absorption and scattering were modeled as a two-component mixture, with the components representing actively growing and senescent material. The specific inherent optical properties of the two components were derived by linear regression of total IOPs against chlorophyll concentration and a fraction of the suspended mineral concentration. These specific IOPs were used to develop radiative transfer models of diatom blooms in varying stages of growth and senescence. Remote sensing reflectances calculated using this technique confirmed the tendency of the standard algorithms employed in SeaWiFS, MODIS and MERIS data processing to under-estimate near-surface chlorophyll concentrations in diatom blooms. However the inclusion of increasing proportions of senescent material had a significant effect on algorithm performance only at chlorophyll concentrations below 10 mg m(-3). Optical depths predicted by the ... Article in Journal/Newspaper Southern Ocean Natural Environment Research Council: NERC Open Research Archive Southern Ocean Remote Sensing of Environment 115 6 1434 1442 |
institution |
Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
topic |
Marine Sciences Biology and Microbiology Electronics Engineering and Technology |
spellingShingle |
Marine Sciences Biology and Microbiology Electronics Engineering and Technology Cunningham, Alex Carrie, Iain D. Korb, Rebecca E. Two-component modeling of the optical properties of a diatom bloom in the Southern ocean |
topic_facet |
Marine Sciences Biology and Microbiology Electronics Engineering and Technology |
description |
Diatom cells have distinctive optical characteristics, originating from their relatively large cell size, fucoxanthin content and silica cell wall. It has been proposed that diatom-dominated phytoplankton blooms can be identified by optical remote sensing and that specifically tuned chlorophyll and primary production algorithms should be applied in regions where these blooms are present. However there have been few studies on how the optical properties of diatom blooms change as they progress from active growth to senescence, and it is unlikely that measurements on laboratory cultures encompass the full range of physiological states found in natural waters. We have therefore examined the inherent optical properties (IOPs) of the waters around the island of South Georgia at the end of the spring diatom bloom. Considerable variability was found in the relationships between the inherent optical properties and analytically determined chlorophyll a concentrations even in the surface layer, which meant that the usual bio-optical assumptions for Case 1 waters did not apply. To account for this variability, phytoplankton absorption and scattering were modeled as a two-component mixture, with the components representing actively growing and senescent material. The specific inherent optical properties of the two components were derived by linear regression of total IOPs against chlorophyll concentration and a fraction of the suspended mineral concentration. These specific IOPs were used to develop radiative transfer models of diatom blooms in varying stages of growth and senescence. Remote sensing reflectances calculated using this technique confirmed the tendency of the standard algorithms employed in SeaWiFS, MODIS and MERIS data processing to under-estimate near-surface chlorophyll concentrations in diatom blooms. However the inclusion of increasing proportions of senescent material had a significant effect on algorithm performance only at chlorophyll concentrations below 10 mg m(-3). Optical depths predicted by the ... |
format |
Article in Journal/Newspaper |
author |
Cunningham, Alex Carrie, Iain D. Korb, Rebecca E. |
author_facet |
Cunningham, Alex Carrie, Iain D. Korb, Rebecca E. |
author_sort |
Cunningham, Alex |
title |
Two-component modeling of the optical properties of a diatom bloom in the Southern ocean |
title_short |
Two-component modeling of the optical properties of a diatom bloom in the Southern ocean |
title_full |
Two-component modeling of the optical properties of a diatom bloom in the Southern ocean |
title_fullStr |
Two-component modeling of the optical properties of a diatom bloom in the Southern ocean |
title_full_unstemmed |
Two-component modeling of the optical properties of a diatom bloom in the Southern ocean |
title_sort |
two-component modeling of the optical properties of a diatom bloom in the southern ocean |
publisher |
Elsevier |
publishDate |
2011 |
url |
http://nora.nerc.ac.uk/id/eprint/14494/ |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
Cunningham, Alex; Carrie, Iain D.; Korb, Rebecca E. 2011 Two-component modeling of the optical properties of a diatom bloom in the Southern ocean. Remote Sensing of Environment, 115 (6). 1434-1442. https://doi.org/10.1016/j.rse.2011.01.023 <https://doi.org/10.1016/j.rse.2011.01.023> |
op_doi |
https://doi.org/10.1016/j.rse.2011.01.023 |
container_title |
Remote Sensing of Environment |
container_volume |
115 |
container_issue |
6 |
container_start_page |
1434 |
op_container_end_page |
1442 |
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1766207561021784064 |