High latitude Southern Ocean phytoplankton have distinctive bio-optical properties
Abstract: Studying the biogeochemistry of the Southern Ocean using remote sensing relies on accurate interpretation of ocean colour through bio-optical and biogeochemical relationships between quantities and properties of interest. During the Antarctic Circumnavigation Expedition of the 2016/2017Aus...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
| Language: | English |
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Optical Society of America (OSA)
2021
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| Online Access: | http://purl.org/au-research/grants/arc/DP160103387 http://hdl.handle.net/20.500.11937/89993 |
| _version_ | 1848765304760434688 |
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| author | Robinson, Charlotte Huot, Yannick Schuback, Nina Ryan-Keogh, Thomas J Thomalla, Sandy J Antoine, David |
| author_facet | Robinson, Charlotte Huot, Yannick Schuback, Nina Ryan-Keogh, Thomas J Thomalla, Sandy J Antoine, David |
| author_sort | Robinson, Charlotte |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Abstract: Studying the biogeochemistry of the Southern Ocean using remote sensing relies on accurate interpretation of ocean colour through bio-optical and biogeochemical relationships between quantities and properties of interest. During the Antarctic Circumnavigation Expedition of the 2016/2017Austral Summer,we collected a spatially comprehensive dataset of phytoplankton pigment concentrations, particulate absorption and particle size distribution and compared simple bio-optical and particle property relationships as a function of chlorophyll a. Similar to previous studies we find that the chlorophyll-specific phytoplankton absorption coefficient is significantly lower than in other oceans at comparable chlorophyll concentrations. This appears to be driven in part by lower concentrations of accessory pigments per unit chlorophyll a as well as increased pigment packaging due to relatively larger sized phytoplankton at low chlorophyll a than is typically observed in other oceans. We find that the contribution of microphytoplankton (>20 μm size) to chlorophyll a estimates of phytoplankton biomass is significantly higher than expected for the given chlorophyll a concentration, especially in higher latitudes south of the Southern Antarctic Circumpolar Current Front. Phytoplankton pigments are more packaged in larger cells, which resulted in a flattening of phytoplankton spectra as measured in these samples when compared to other ocean regions with similar chlorophyll a concentration. Additionally, we find that at high latitude locations in the Southern Ocean, pheopigment concentrations can exceed mono-vinyl chlorophyll a concentrations. Finally, we observed very different relationships between particle volume and chlorophyll a concentrations in high and low latitude Southern Ocean waters, driven by differences in phytoplankton community composition and acclimation to environmental conditions and varying contribution of non-algal particles to the particulate matter. Our data confirm that, as previously suggested, the relationships between bio-optical properties and chlorophyll a in the Southern Ocean are different to other oceans. In addition, distinct bio-optical properties were evident between high and low latitude regions of the Southern Ocean basin. Here we provide a region-specific set of power law functions describing the phytoplankton absorption spectrum as a function of chlorophyll a. |
| first_indexed | 2025-11-14T11:33:08Z |
| format | Journal Article |
| id | curtin-20.500.11937-89993 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:33:08Z |
| publishDate | 2021 |
| publisher | Optical Society of America (OSA) |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-899932023-02-06T01:35:28Z High latitude Southern Ocean phytoplankton have distinctive bio-optical properties Robinson, Charlotte Huot, Yannick Schuback, Nina Ryan-Keogh, Thomas J Thomalla, Sandy J Antoine, David Science & Technology Physical Sciences Optics NATURAL IRON-FERTILIZATION SPECTRAL ABSORPTION-COEFFICIENTS NONLINEAR MINIMIZATION SUBJECT CHLOROPHYLL-A CONCENTRATION LIGHT-ABSORPTION IN-SITU OPTICAL-PROPERTIES ANTARCTIC PHYTOPLANKTON PHAEOCYSTIS-ANTARCTICA KERGUELEN PLATEAU Abstract: Studying the biogeochemistry of the Southern Ocean using remote sensing relies on accurate interpretation of ocean colour through bio-optical and biogeochemical relationships between quantities and properties of interest. During the Antarctic Circumnavigation Expedition of the 2016/2017Austral Summer,we collected a spatially comprehensive dataset of phytoplankton pigment concentrations, particulate absorption and particle size distribution and compared simple bio-optical and particle property relationships as a function of chlorophyll a. Similar to previous studies we find that the chlorophyll-specific phytoplankton absorption coefficient is significantly lower than in other oceans at comparable chlorophyll concentrations. This appears to be driven in part by lower concentrations of accessory pigments per unit chlorophyll a as well as increased pigment packaging due to relatively larger sized phytoplankton at low chlorophyll a than is typically observed in other oceans. We find that the contribution of microphytoplankton (>20 μm size) to chlorophyll a estimates of phytoplankton biomass is significantly higher than expected for the given chlorophyll a concentration, especially in higher latitudes south of the Southern Antarctic Circumpolar Current Front. Phytoplankton pigments are more packaged in larger cells, which resulted in a flattening of phytoplankton spectra as measured in these samples when compared to other ocean regions with similar chlorophyll a concentration. Additionally, we find that at high latitude locations in the Southern Ocean, pheopigment concentrations can exceed mono-vinyl chlorophyll a concentrations. Finally, we observed very different relationships between particle volume and chlorophyll a concentrations in high and low latitude Southern Ocean waters, driven by differences in phytoplankton community composition and acclimation to environmental conditions and varying contribution of non-algal particles to the particulate matter. Our data confirm that, as previously suggested, the relationships between bio-optical properties and chlorophyll a in the Southern Ocean are different to other oceans. In addition, distinct bio-optical properties were evident between high and low latitude regions of the Southern Ocean basin. Here we provide a region-specific set of power law functions describing the phytoplankton absorption spectrum as a function of chlorophyll a. 2021 Journal Article http://hdl.handle.net/20.500.11937/89993 10.1364/OE.426737 English http://purl.org/au-research/grants/arc/DP160103387 http://creativecommons.org/licenses/by/4.0/ Optical Society of America (OSA) fulltext |
| spellingShingle | Science & Technology Physical Sciences Optics NATURAL IRON-FERTILIZATION SPECTRAL ABSORPTION-COEFFICIENTS NONLINEAR MINIMIZATION SUBJECT CHLOROPHYLL-A CONCENTRATION LIGHT-ABSORPTION IN-SITU OPTICAL-PROPERTIES ANTARCTIC PHYTOPLANKTON PHAEOCYSTIS-ANTARCTICA KERGUELEN PLATEAU Robinson, Charlotte Huot, Yannick Schuback, Nina Ryan-Keogh, Thomas J Thomalla, Sandy J Antoine, David High latitude Southern Ocean phytoplankton have distinctive bio-optical properties |
| title | High latitude Southern Ocean phytoplankton have distinctive bio-optical properties |
| title_full | High latitude Southern Ocean phytoplankton have distinctive bio-optical properties |
| title_fullStr | High latitude Southern Ocean phytoplankton have distinctive bio-optical properties |
| title_full_unstemmed | High latitude Southern Ocean phytoplankton have distinctive bio-optical properties |
| title_short | High latitude Southern Ocean phytoplankton have distinctive bio-optical properties |
| title_sort | high latitude southern ocean phytoplankton have distinctive bio-optical properties |
| topic | Science & Technology Physical Sciences Optics NATURAL IRON-FERTILIZATION SPECTRAL ABSORPTION-COEFFICIENTS NONLINEAR MINIMIZATION SUBJECT CHLOROPHYLL-A CONCENTRATION LIGHT-ABSORPTION IN-SITU OPTICAL-PROPERTIES ANTARCTIC PHYTOPLANKTON PHAEOCYSTIS-ANTARCTICA KERGUELEN PLATEAU |
| url | http://purl.org/au-research/grants/arc/DP160103387 http://hdl.handle.net/20.500.11937/89993 |