Microbial Interactions in Coupled Climate-Biogeochemical Systems
This thesis addresses time-series analyses of microbial (i.e. marine heterotrophic bacteria and phytoplankton) and microbially relevant ecosystem variables at two ocean time series stations - Palmer Station in the coastal Western Antarctic Peninsula (WAP) and the Bermuda Atlantic Time-series Study (...
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ftdatacite:10.7916/d800085k 2023-05-15T14:05:23+02:00 Microbial Interactions in Coupled Climate-Biogeochemical Systems Kim, Hyewon 2017 https://dx.doi.org/10.7916/d800085k https://academiccommons.columbia.edu/doi/10.7916/D800085K unknown Columbia University Biogeochemistry Marine biology Marine ecology Ecology FOS Biological sciences Marine bacteria Marine phytoplankton Theses Text article-journal ScholarlyArticle 2017 ftdatacite https://doi.org/10.7916/d800085k 2021-11-05T12:55:41Z This thesis addresses time-series analyses of microbial (i.e. marine heterotrophic bacteria and phytoplankton) and microbially relevant ecosystem variables at two ocean time series stations - Palmer Station in the coastal Western Antarctic Peninsula (WAP) and the Bermuda Atlantic Time-series Study (BATS) site in the Sargasso Sea. Using a diverse spectrum of statistical analyses and models, the aim of this thesis is to gain the better insight into 1) variability of microbial and ecosystem processes across varying time scales, from seasonal to interdecadal, and 2) how each process is influenced by variability of surrounding local physical forcing factors as well as regional and global-scale climate variability along the study region. Chapter 1 provides an introduction to the two study sites as well as a brief history of the ocean time-series programs there. Chapter 2 deals with phytoplankton and nutrient drawdown variability over an interdecadal (1993-2013) period using seasonal time-series variables collected at Palmer Station during full 6-months of Austral growing seasons (October-March). Specifically, the linkage between large-scale climate modes relevant to the WAP area and phytoplankton and nutrient patterns is explored to establish the underlying mechanisms of the observed ecosystem variability, which is ultimately triggered by climate conditions via mediatory physical forcing factors. Chapter 3 addresses a decadal (2002-2014) variability of heterotrophic bacterial variables collected at Palmer Station in Antarctica. This Chapter 3 provides an insight into why bacterial activity was shown to be restricted in this very productive ecosystem from diverse aspects gained using different statistical approaches. Furthermore, the linkage between bacterial properties and surrounding environmental conditions is explored. Finally, Chapter 4 concerns an event-scale phenomenon - the frequency of winter storms - and its impact on bacterial dynamics and ecological processes at the BATS site. Using a previously developed storm tracking algorithm, this study benefits from establishing a mechanistic connection between storm forcing and bacterial processes via storm-induced variability of physical environments - the extent of wind-mixing and entrainment of cold water into the upper mixed-layer. The finding of Chapter 4 is novel in the aspect that prevalent negative North Atlantic Oscillation (NAO) conditions, which lead to frequent arrivals of winter storms over the BATS region, in part, explain a significant decreasing bacterial trend over the past 24-year period. Overall, my thesis, in conjunction with work performed by fellow microbial oceanographers, aims to provide evidence of microbial responses to physical forcings across varying time scales in the strongly coupled climate-biogeochemical systems at two contrasting ocean sites based on a variety of statistical approaches. Thesis Antarc* Antarctic Antarctic Peninsula Antarctica North Atlantic North Atlantic oscillation DataCite Metadata Store (German National Library of Science and Technology) Antarctic Antarctic Peninsula Austral Palmer Station ENVELOPE(-64.050,-64.050,-64.770,-64.770) Palmer-Station ENVELOPE(-64.050,-64.050,-64.770,-64.770) |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
unknown |
topic |
Biogeochemistry Marine biology Marine ecology Ecology FOS Biological sciences Marine bacteria Marine phytoplankton |
spellingShingle |
Biogeochemistry Marine biology Marine ecology Ecology FOS Biological sciences Marine bacteria Marine phytoplankton Kim, Hyewon Microbial Interactions in Coupled Climate-Biogeochemical Systems |
topic_facet |
Biogeochemistry Marine biology Marine ecology Ecology FOS Biological sciences Marine bacteria Marine phytoplankton |
description |
This thesis addresses time-series analyses of microbial (i.e. marine heterotrophic bacteria and phytoplankton) and microbially relevant ecosystem variables at two ocean time series stations - Palmer Station in the coastal Western Antarctic Peninsula (WAP) and the Bermuda Atlantic Time-series Study (BATS) site in the Sargasso Sea. Using a diverse spectrum of statistical analyses and models, the aim of this thesis is to gain the better insight into 1) variability of microbial and ecosystem processes across varying time scales, from seasonal to interdecadal, and 2) how each process is influenced by variability of surrounding local physical forcing factors as well as regional and global-scale climate variability along the study region. Chapter 1 provides an introduction to the two study sites as well as a brief history of the ocean time-series programs there. Chapter 2 deals with phytoplankton and nutrient drawdown variability over an interdecadal (1993-2013) period using seasonal time-series variables collected at Palmer Station during full 6-months of Austral growing seasons (October-March). Specifically, the linkage between large-scale climate modes relevant to the WAP area and phytoplankton and nutrient patterns is explored to establish the underlying mechanisms of the observed ecosystem variability, which is ultimately triggered by climate conditions via mediatory physical forcing factors. Chapter 3 addresses a decadal (2002-2014) variability of heterotrophic bacterial variables collected at Palmer Station in Antarctica. This Chapter 3 provides an insight into why bacterial activity was shown to be restricted in this very productive ecosystem from diverse aspects gained using different statistical approaches. Furthermore, the linkage between bacterial properties and surrounding environmental conditions is explored. Finally, Chapter 4 concerns an event-scale phenomenon - the frequency of winter storms - and its impact on bacterial dynamics and ecological processes at the BATS site. Using a previously developed storm tracking algorithm, this study benefits from establishing a mechanistic connection between storm forcing and bacterial processes via storm-induced variability of physical environments - the extent of wind-mixing and entrainment of cold water into the upper mixed-layer. The finding of Chapter 4 is novel in the aspect that prevalent negative North Atlantic Oscillation (NAO) conditions, which lead to frequent arrivals of winter storms over the BATS region, in part, explain a significant decreasing bacterial trend over the past 24-year period. Overall, my thesis, in conjunction with work performed by fellow microbial oceanographers, aims to provide evidence of microbial responses to physical forcings across varying time scales in the strongly coupled climate-biogeochemical systems at two contrasting ocean sites based on a variety of statistical approaches. |
format |
Thesis |
author |
Kim, Hyewon |
author_facet |
Kim, Hyewon |
author_sort |
Kim, Hyewon |
title |
Microbial Interactions in Coupled Climate-Biogeochemical Systems |
title_short |
Microbial Interactions in Coupled Climate-Biogeochemical Systems |
title_full |
Microbial Interactions in Coupled Climate-Biogeochemical Systems |
title_fullStr |
Microbial Interactions in Coupled Climate-Biogeochemical Systems |
title_full_unstemmed |
Microbial Interactions in Coupled Climate-Biogeochemical Systems |
title_sort |
microbial interactions in coupled climate-biogeochemical systems |
publisher |
Columbia University |
publishDate |
2017 |
url |
https://dx.doi.org/10.7916/d800085k https://academiccommons.columbia.edu/doi/10.7916/D800085K |
long_lat |
ENVELOPE(-64.050,-64.050,-64.770,-64.770) ENVELOPE(-64.050,-64.050,-64.770,-64.770) |
geographic |
Antarctic Antarctic Peninsula Austral Palmer Station Palmer-Station |
geographic_facet |
Antarctic Antarctic Peninsula Austral Palmer Station Palmer-Station |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica North Atlantic North Atlantic oscillation |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica North Atlantic North Atlantic oscillation |
op_doi |
https://doi.org/10.7916/d800085k |
_version_ |
1766277241209094144 |