Surface chlorophyll variability in the Drake Passage region of the Southern Ocean
The Southern Ocean, the ocean surrounding the Antarctic continent, supports a diverse array of biological species and unique food webs. Given the important role of phytoplankton in Southern Ocean food webs and their influence on the global carbon reservoir, it is of interest to know whether their ab...
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ftunicolboulder:oai:scholar.colorado.edu:honr_theses-2238 2023-05-15T13:36:09+02:00 Surface chlorophyll variability in the Drake Passage region of the Southern Ocean Gradone, Joseph C 2016-01-01T08:00:00Z application/pdf https://scholar.colorado.edu/honr_theses/1134 https://scholar.colorado.edu/cgi/viewcontent.cgi?article=2238&context=honr_theses unknown CU Scholar https://scholar.colorado.edu/honr_theses/1134 https://scholar.colorado.edu/cgi/viewcontent.cgi?article=2238&context=honr_theses Undergraduate Honors Theses Southern Ocean Phytoplankton Biogeochemistry Fall Bloom Chlorophyll Oceanography Oceanography and Atmospheric Sciences and Meteorology text 2016 ftunicolboulder 2018-10-07T08:46:34Z The Southern Ocean, the ocean surrounding the Antarctic continent, supports a diverse array of biological species and unique food webs. Given the important role of phytoplankton in Southern Ocean food webs and their influence on the global carbon reservoir, it is of interest to know whether their abundance has changed over time. Chlorophyll is a pigment present in all photosynthesizing phytoplankton that can be used to estimate the biomass and productivity of phytoplankton at a given time and location. This study analyzes surface chlorophyll variability in the Drake Passage region of the Southern Ocean using underway fluorometer derived chlorophyll from the ARSV Laurence M. Gould (2002-2015), along with satellite derived chlorophyll-a estimates from the MODIS sensor. We observe an austral fall bloom in the underway fluorometer record, ranging from 40%-100% of the maximum bloom concentration in a given year. This bloom is significant due to its timing and magnitude, and due to its absence from the recent relevant literature. We propose that recent studies failed to observe a fall bloom in this region due to reliance on satellite-derived estimates of chlorophyll for which there exist very few valid estimates in the Drake Passage during the austral fall. Analysis of MODIS estimates of chlorophyll also revealed that this sensor systematically underestimates chlorophyll concentration in the Drake Passage region. Lastly, a weak statistical relationship between surface ocean pCO2 and fluorometer-based chlorophyll was observed in the Drake Passage. We suspect that this weak relationship is due to the opposing effects of the thermally driven component of pCO2 and the component of pCO2 due to changes in total dissolved inorganic carbon. Text Antarc* Antarctic Drake Passage Southern Ocean University of Colorado, Boulder: CU Scholar Antarctic Southern Ocean The Antarctic Austral Drake Passage |
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University of Colorado, Boulder: CU Scholar |
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ftunicolboulder |
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topic |
Southern Ocean Phytoplankton Biogeochemistry Fall Bloom Chlorophyll Oceanography Oceanography and Atmospheric Sciences and Meteorology |
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Southern Ocean Phytoplankton Biogeochemistry Fall Bloom Chlorophyll Oceanography Oceanography and Atmospheric Sciences and Meteorology Gradone, Joseph C Surface chlorophyll variability in the Drake Passage region of the Southern Ocean |
topic_facet |
Southern Ocean Phytoplankton Biogeochemistry Fall Bloom Chlorophyll Oceanography Oceanography and Atmospheric Sciences and Meteorology |
description |
The Southern Ocean, the ocean surrounding the Antarctic continent, supports a diverse array of biological species and unique food webs. Given the important role of phytoplankton in Southern Ocean food webs and their influence on the global carbon reservoir, it is of interest to know whether their abundance has changed over time. Chlorophyll is a pigment present in all photosynthesizing phytoplankton that can be used to estimate the biomass and productivity of phytoplankton at a given time and location. This study analyzes surface chlorophyll variability in the Drake Passage region of the Southern Ocean using underway fluorometer derived chlorophyll from the ARSV Laurence M. Gould (2002-2015), along with satellite derived chlorophyll-a estimates from the MODIS sensor. We observe an austral fall bloom in the underway fluorometer record, ranging from 40%-100% of the maximum bloom concentration in a given year. This bloom is significant due to its timing and magnitude, and due to its absence from the recent relevant literature. We propose that recent studies failed to observe a fall bloom in this region due to reliance on satellite-derived estimates of chlorophyll for which there exist very few valid estimates in the Drake Passage during the austral fall. Analysis of MODIS estimates of chlorophyll also revealed that this sensor systematically underestimates chlorophyll concentration in the Drake Passage region. Lastly, a weak statistical relationship between surface ocean pCO2 and fluorometer-based chlorophyll was observed in the Drake Passage. We suspect that this weak relationship is due to the opposing effects of the thermally driven component of pCO2 and the component of pCO2 due to changes in total dissolved inorganic carbon. |
format |
Text |
author |
Gradone, Joseph C |
author_facet |
Gradone, Joseph C |
author_sort |
Gradone, Joseph C |
title |
Surface chlorophyll variability in the Drake Passage region of the Southern Ocean |
title_short |
Surface chlorophyll variability in the Drake Passage region of the Southern Ocean |
title_full |
Surface chlorophyll variability in the Drake Passage region of the Southern Ocean |
title_fullStr |
Surface chlorophyll variability in the Drake Passage region of the Southern Ocean |
title_full_unstemmed |
Surface chlorophyll variability in the Drake Passage region of the Southern Ocean |
title_sort |
surface chlorophyll variability in the drake passage region of the southern ocean |
publisher |
CU Scholar |
publishDate |
2016 |
url |
https://scholar.colorado.edu/honr_theses/1134 https://scholar.colorado.edu/cgi/viewcontent.cgi?article=2238&context=honr_theses |
geographic |
Antarctic Southern Ocean The Antarctic Austral Drake Passage |
geographic_facet |
Antarctic Southern Ocean The Antarctic Austral Drake Passage |
genre |
Antarc* Antarctic Drake Passage Southern Ocean |
genre_facet |
Antarc* Antarctic Drake Passage Southern Ocean |
op_source |
Undergraduate Honors Theses |
op_relation |
https://scholar.colorado.edu/honr_theses/1134 https://scholar.colorado.edu/cgi/viewcontent.cgi?article=2238&context=honr_theses |
_version_ |
1766074900045365248 |