{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/159959"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/159959","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"Cross-Frontal Exchange at the US Northeast Shelfbreak","abstract":"Exchange across the semipermeable US Northeast shelfbreak front is a potential driver of irreversible change to the continental shelf waters, its productive ecosystem, and economically valuable fisheries. However, cross-frontal exchange is difficult to observe directly because it is highly intermittent, non-linear, and driven by both internal frontal instability and external forcing. In this thesis, I quantify eddy-driven exchange across the US Northeast shelfbreak front and its impact on the coastal ocean, starting on seasonal timescales and moving toward individual synoptic events. For this task, I take advantage of unprecedented multi-year observations from the Ocean Observatories Initiative (OOI) Coastal Pioneer Array (2014-2022). On seasonal timescales, the buoyancy-driven shelfbreak front is persistently trapped at the shelfbreak, which supports theoretical predictions of shelfbreak frontogenesis (Chapter 2). However, exchange across the shelfbreak front leads to a significant increase in salinity on the continental shelf between spring and fall. A volume budget of the subsurface continental shelf 'cold pool', habitat of the valuable benthic ecosystem, quantifies the contribution of eddy-driven advection to the observed salinity increase and explains the seasonal cycle of watermass variability on the shelf (Chapter 3). However, the multi-year averaged cold pool watermass budget does not capture the intermittency of cross-shelfbreak eddy-fluxes on synoptic timescales. Thus, I demonstrate how individual mooring timeseries can be used to capture the statistical distribution of eddy-driven exchange by assessing cross-shelfbreak eddy-covariance fluxes of salt and heat (Chapter 4). Mean eddy-covariance fluxes align well with previous residual estimates of cross-shelfbreak exchange to close coastal watermass budgets, and just 10-20% of statistically anomalous events are responsible for half the multi-year mean flux. To characterize rapid changes in continental shelf watermass properties over short timescales, I investigate the decline of seasonal stratification due to individual weather events and identify signatures of cross-shelfbreak exchange in wind-driven destratification (Chapter 5). Altogether, this thesis extends our understanding of the characteristics, timing, and magnitude of eddy-driven exchange across the US Northeast shelfbreak front on varying timescales. This information can help to inform how large-scale, long-term trends will impact the US East Coast coastal ocean and its marine ecosystem.","abstract_html":"Exchange across the semipermeable US Northeast shelfbreak front is a potential driver of irreversible change to the continental shelf waters, its productive ecosystem, and economically valuable fisheries. However, cross-frontal exchange is difficult to observe directly because it is highly intermittent, non-linear, and driven by both internal frontal instability and external forcing. In this thesis, I quantify eddy-driven exchange across the US Northeast shelfbreak front and its impact on the coastal ocean, starting on seasonal timescales and moving toward individual synoptic events. For this task, I take advantage of unprecedented multi-year observations from the Ocean Observatories Initiative (OOI) Coastal Pioneer Array (2014-2022). On seasonal timescales, the buoyancy-driven shelfbreak front is persistently trapped at the shelfbreak, which supports theoretical predictions of shelfbreak frontogenesis (Chapter 2). However, exchange across the shelfbreak front leads to a significant increase in salinity on the continental shelf between spring and fall. A volume budget of the subsurface continental shelf 'cold pool', habitat of the valuable benthic ecosystem, quantifies the contribution of eddy-driven advection to the observed salinity increase and explains the seasonal cycle of watermass variability on the shelf (Chapter 3). However, the multi-year averaged cold pool watermass budget does not capture the intermittency of cross-shelfbreak eddy-fluxes on synoptic timescales. Thus, I demonstrate how individual mooring timeseries can be used to capture the statistical distribution of eddy-driven exchange by assessing cross-shelfbreak eddy-covariance fluxes of salt and heat (Chapter 4). Mean eddy-covariance fluxes align well with previous residual estimates of cross-shelfbreak exchange to close coastal watermass budgets, and just 10-20% of statistically anomalous events are responsible for half the multi-year mean flux. To characterize rapid changes in continental shelf watermass properties over short timescales, I investigate the decline of seasonal stratification due to individual weather events and identify signatures of cross-shelfbreak exchange in wind-driven destratification (Chapter 5). Altogether, this thesis extends our understanding of the characteristics, timing, and magnitude of eddy-driven exchange across the US Northeast shelfbreak front on varying timescales. This information can help to inform how large-scale, long-term trends will impact the US East Coast coastal ocean and its marine ecosystem.","abstract_has_math":false,"creators":["Taenzer, Lukas L."],"institution":"Massachusetts Institute of Technology","degree_name":"Doctoral","degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences","school":null,"contributors":[],"advisors":["Gawarkiewicz, Glen G.","Plueddemann, Albert J."],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-05","date_published":"2025-05","updated_at":"2026-07-22T22:21:36Z","subjects":[],"languages":[],"rights":["In Copyright - Educational Use Permitted","Copyright retained by author(s)"],"rights_urls":["https://rightsstatements.org/page/InC-EDU/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/1721.1/159959","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Gawarkiewicz, Glen G.","Plueddemann, Albert J."]},{"key":"dc:contributor.department","label":"Department","values":["Massachusetts Institute of Technology. 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However, cross-frontal exchange is difficult to observe directly because it is highly intermittent, non-linear, and driven by both internal frontal instability and external forcing. In this thesis, I quantify eddy-driven exchange across the US Northeast shelfbreak front and its impact on the coastal ocean, starting on seasonal timescales and moving toward individual synoptic events. For this task, I take advantage of unprecedented multi-year observations from the Ocean Observatories Initiative (OOI) Coastal Pioneer Array (2014-2022). On seasonal timescales, the buoyancy-driven shelfbreak front is persistently trapped at the shelfbreak, which supports theoretical predictions of shelfbreak frontogenesis (Chapter 2). However, exchange across the shelfbreak front leads to a significant increase in salinity on the continental shelf between spring and fall. A volume budget of the subsurface continental shelf 'cold pool', habitat of the valuable benthic ecosystem, quantifies the contribution of eddy-driven advection to the observed salinity increase and explains the seasonal cycle of watermass variability on the shelf (Chapter 3). However, the multi-year averaged cold pool watermass budget does not capture the intermittency of cross-shelfbreak eddy-fluxes on synoptic timescales. Thus, I demonstrate how individual mooring timeseries can be used to capture the statistical distribution of eddy-driven exchange by assessing cross-shelfbreak eddy-covariance fluxes of salt and heat (Chapter 4). Mean eddy-covariance fluxes align well with previous residual estimates of cross-shelfbreak exchange to close coastal watermass budgets, and just 10-20% of statistically anomalous events are responsible for half the multi-year mean flux. To characterize rapid changes in continental shelf watermass properties over short timescales, I investigate the decline of seasonal stratification due to individual weather events and identify signatures of cross-shelfbreak exchange in wind-driven destratification (Chapter 5). Altogether, this thesis extends our understanding of the characteristics, timing, and magnitude of eddy-driven exchange across the US Northeast shelfbreak front on varying timescales. This information can help to inform how large-scale, long-term trends will impact the US East Coast coastal ocean and its marine ecosystem."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph.D."]},{"key":"dc:title","label":"Title","values":["Cross-Frontal Exchange at the US Northeast Shelfbreak"]}]}],"canonical_facts":{"dc:contributor.advisor":["Gawarkiewicz, Glen G.","Plueddemann, Albert J."],"dc:contributor.department":["Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences"],"dc:creator":["Taenzer, Lukas L."],"dc:date.accessioned":["2025-07-07T17:40:34Z"],"dc:date.available":["2025-07-07T17:40:34Z"],"dc:date.issued":["2025-05"],"dc:description.abstract":["Exchange across the semipermeable US Northeast shelfbreak front is a potential driver of irreversible change to the continental shelf waters, its productive ecosystem, and economically valuable fisheries. However, cross-frontal exchange is difficult to observe directly because it is highly intermittent, non-linear, and driven by both internal frontal instability and external forcing. In this thesis, I quantify eddy-driven exchange across the US Northeast shelfbreak front and its impact on the coastal ocean, starting on seasonal timescales and moving toward individual synoptic events. For this task, I take advantage of unprecedented multi-year observations from the Ocean Observatories Initiative (OOI) Coastal Pioneer Array (2014-2022). On seasonal timescales, the buoyancy-driven shelfbreak front is persistently trapped at the shelfbreak, which supports theoretical predictions of shelfbreak frontogenesis (Chapter 2). However, exchange across the shelfbreak front leads to a significant increase in salinity on the continental shelf between spring and fall. A volume budget of the subsurface continental shelf 'cold pool', habitat of the valuable benthic ecosystem, quantifies the contribution of eddy-driven advection to the observed salinity increase and explains the seasonal cycle of watermass variability on the shelf (Chapter 3). However, the multi-year averaged cold pool watermass budget does not capture the intermittency of cross-shelfbreak eddy-fluxes on synoptic timescales. Thus, I demonstrate how individual mooring timeseries can be used to capture the statistical distribution of eddy-driven exchange by assessing cross-shelfbreak eddy-covariance fluxes of salt and heat (Chapter 4). Mean eddy-covariance fluxes align well with previous residual estimates of cross-shelfbreak exchange to close coastal watermass budgets, and just 10-20% of statistically anomalous events are responsible for half the multi-year mean flux. To characterize rapid changes in continental shelf watermass properties over short timescales, I investigate the decline of seasonal stratification due to individual weather events and identify signatures of cross-shelfbreak exchange in wind-driven destratification (Chapter 5). Altogether, this thesis extends our understanding of the characteristics, timing, and magnitude of eddy-driven exchange across the US Northeast shelfbreak front on varying timescales. This information can help to inform how large-scale, long-term trends will impact the US East Coast coastal ocean and its marine ecosystem."],"dc:description.degree":["Ph.D."],"dc:identifier.uri":["https://hdl.handle.net/1721.1/159959"],"dc:publisher":["Massachusetts Institute of Technology"],"dc:rights":["In Copyright - Educational Use Permitted","Copyright retained by author(s)"],"dc:rights.uri":["https://rightsstatements.org/page/InC-EDU/1.0/"],"dc:title":["Cross-Frontal Exchange at the US Northeast Shelfbreak"],"dc:type":["Thesis"],"thesis:degree_name":["Doctoral","Doctor of Philosophy"]},"updated_at":"2026-07-22T22:21:36Z"}