Variability In The Circulation, Temperature, And Salinity Fields Of The Eastern Bering Sea Shelf In Response To Atomospheric Forcing
Dissertation (Ph.D.) University of Alaska Fairbanks, 2012 Although the Bering Sea shelf plays a critical role in mediating the global climate and supports one of the world's largest fisheries, fundamental questions remain about the role of advection on its salt, fresh water, heat and nutrient b...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/9121 2023-05-15T13:15:08+02:00 Variability In The Circulation, Temperature, And Salinity Fields Of The Eastern Bering Sea Shelf In Response To Atomospheric Forcing Danielson, Seth Lombard Weingartner, Thomas Aagaard, Knut Coyle, Kenneth Hedstrom, Katherine Kowalik, Zygmunt 2012 http://hdl.handle.net/11122/9121 unknown http://hdl.handle.net/11122/9121 Program in Marine Science and Limnology Physical oceanography Dissertation phd 2012 ftunivalaska 2023-02-23T21:37:12Z Dissertation (Ph.D.) University of Alaska Fairbanks, 2012 Although the Bering Sea shelf plays a critical role in mediating the global climate and supports one of the world's largest fisheries, fundamental questions remain about the role of advection on its salt, fresh water, heat and nutrient budgets. I quantify seasonal and inter-annual variability in the temperature, salinity and circulation fields. Shipboard survey temperature and salinity data from summer's end reveal that advection affects the inter-annual variability of fresh water and heat content: heat content anomalies are set by along-shelf summer Ekman transport anomalies whereas fresh water content anomalies are determined by wind direction anomalies averaged over the previous fall, winter and early spring. The latter is consistent with an inverse relationship between coastal and mid-shelf salinity anomalies and late summer -- winter cross-shelf motion of satellite-tracked drifters. These advection anomalies result from the position and strength of the Aleutian Low pressure system. Mooring data applied to the vertically integrated equations of motion show that the momentum balance is primarily geostrophic within at least one external deformation radius of the coast. Local accelerations, wind stress and bottom friction account for < 20% (up to 40%) of the along- (cross-) isobath momentum balance, depending on location and season. Wind-forced surface Ekman divergence is primarily responsible for flow variations. The shelf changes abruptly from strong coastal convergence conditions to strong coastal divergence conditions for winds directed to the south and for winds directed to the west, respectively, and substantial portions of the shelf's currents reorganize between these two modes of wind forcing. Based on the above observations and supporting numerical model integrations, I propose a simple framework for considering the shelf-wide circulation response to variations in wind forcing. Under southeasterly winds, northward transport increases and ... Doctoral or Postdoctoral Thesis aleutian low Bering Sea Alaska University of Alaska: ScholarWorks@UA Bering Sea Fairbanks |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
unknown |
topic |
Physical oceanography |
spellingShingle |
Physical oceanography Danielson, Seth Lombard Variability In The Circulation, Temperature, And Salinity Fields Of The Eastern Bering Sea Shelf In Response To Atomospheric Forcing |
topic_facet |
Physical oceanography |
description |
Dissertation (Ph.D.) University of Alaska Fairbanks, 2012 Although the Bering Sea shelf plays a critical role in mediating the global climate and supports one of the world's largest fisheries, fundamental questions remain about the role of advection on its salt, fresh water, heat and nutrient budgets. I quantify seasonal and inter-annual variability in the temperature, salinity and circulation fields. Shipboard survey temperature and salinity data from summer's end reveal that advection affects the inter-annual variability of fresh water and heat content: heat content anomalies are set by along-shelf summer Ekman transport anomalies whereas fresh water content anomalies are determined by wind direction anomalies averaged over the previous fall, winter and early spring. The latter is consistent with an inverse relationship between coastal and mid-shelf salinity anomalies and late summer -- winter cross-shelf motion of satellite-tracked drifters. These advection anomalies result from the position and strength of the Aleutian Low pressure system. Mooring data applied to the vertically integrated equations of motion show that the momentum balance is primarily geostrophic within at least one external deformation radius of the coast. Local accelerations, wind stress and bottom friction account for < 20% (up to 40%) of the along- (cross-) isobath momentum balance, depending on location and season. Wind-forced surface Ekman divergence is primarily responsible for flow variations. The shelf changes abruptly from strong coastal convergence conditions to strong coastal divergence conditions for winds directed to the south and for winds directed to the west, respectively, and substantial portions of the shelf's currents reorganize between these two modes of wind forcing. Based on the above observations and supporting numerical model integrations, I propose a simple framework for considering the shelf-wide circulation response to variations in wind forcing. Under southeasterly winds, northward transport increases and ... |
author2 |
Weingartner, Thomas Aagaard, Knut Coyle, Kenneth Hedstrom, Katherine Kowalik, Zygmunt |
format |
Doctoral or Postdoctoral Thesis |
author |
Danielson, Seth Lombard |
author_facet |
Danielson, Seth Lombard |
author_sort |
Danielson, Seth Lombard |
title |
Variability In The Circulation, Temperature, And Salinity Fields Of The Eastern Bering Sea Shelf In Response To Atomospheric Forcing |
title_short |
Variability In The Circulation, Temperature, And Salinity Fields Of The Eastern Bering Sea Shelf In Response To Atomospheric Forcing |
title_full |
Variability In The Circulation, Temperature, And Salinity Fields Of The Eastern Bering Sea Shelf In Response To Atomospheric Forcing |
title_fullStr |
Variability In The Circulation, Temperature, And Salinity Fields Of The Eastern Bering Sea Shelf In Response To Atomospheric Forcing |
title_full_unstemmed |
Variability In The Circulation, Temperature, And Salinity Fields Of The Eastern Bering Sea Shelf In Response To Atomospheric Forcing |
title_sort |
variability in the circulation, temperature, and salinity fields of the eastern bering sea shelf in response to atomospheric forcing |
publishDate |
2012 |
url |
http://hdl.handle.net/11122/9121 |
geographic |
Bering Sea Fairbanks |
geographic_facet |
Bering Sea Fairbanks |
genre |
aleutian low Bering Sea Alaska |
genre_facet |
aleutian low Bering Sea Alaska |
op_relation |
http://hdl.handle.net/11122/9121 Program in Marine Science and Limnology |
_version_ |
1766267088967565312 |