Response of major modes of eastern Arctic Ocean variability to climate change
Dissertation (Ph.D.) University of Alaska Fairbanks, 2019 The Arctic Ocean plays a central role in ongoing climate change, with sea ice loss being the most prominent indicator. Recent observations showed that Atlantic inflows play an increasingly important role in the demise of sea ice. This encroach...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/10886 2023-05-15T14:41:23+02:00 Response of major modes of eastern Arctic Ocean variability to climate change Baumann, Till M. Polyakov, Igor V. Bhatt, Uma S. Walsh, John E. Weingartner, Thomas J. 2019-12 http://hdl.handle.net/11122/10886 en_US eng http://hdl.handle.net/11122/10886 Department of Atmospheric Sciences ocean currents Arctic Ocean climatic changes hydrography oceanography Dissertation phd 2019 ftunivalaska 2023-02-23T21:37:35Z Dissertation (Ph.D.) University of Alaska Fairbanks, 2019 The Arctic Ocean plays a central role in ongoing climate change, with sea ice loss being the most prominent indicator. Recent observations showed that Atlantic inflows play an increasingly important role in the demise of sea ice. This encroaching atlantification of the eastern Arctic Ocean impacts the mean state and the variability of hydrography and current dynamics throughout the basin. Among the most energetic modes of variability are the seasonal cycle and high frequency semidiurnal (∼12-hourly) dynamics in the tidal and inertial frequency band. Limited observations indicated a substantial increase of both, hydrographic seasonal cycles as well as semidiurnal current dynamics in the eastern Arctic over the last decade. Using a uniquely comprehensive data set from an array of six moorings deployed across the eastern Eurasian Basin (EB) continental slope along the 125°E meridian between 2013 and 2015 within the NABOS project, we assess the state of hydrographic seasonal cycles in the eastern EB. Results show a complex pattern of seasonality with a remarkably strong (∆T=1.4°C), deep reaching (∼600 m) temperature signal over the continental slope and large-scale seasonal displacements of isopycnal interfaces. Seasonally changing background conditions are also the main source of variability of semidiurnal frequency band currents: During winter, vigorous baroclinic tidal currents whose amplitudes by far exceed predictions follow the vertical evolution of the pycnocline. During summer, extensive open-water periods additionally lead to strong wind-driven inertial currents in the upper ocean, routinely exceeding 30 cm/s far offshore in the deep basin. In order to obtain an Arctic-wide perspective on the impact of baroclinic tidal currents, a pan-Arctic tidal current atlas has been developed that synthesizes all available observations from the last 20 years. This atlas allows for in-depth studies of regional baroclinic tidal current variability as well as for ... Doctoral or Postdoctoral Thesis Arctic Arctic Ocean Climate change Sea ice Alaska University of Alaska: ScholarWorks@UA Arctic Arctic Ocean Fairbanks |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
topic |
ocean currents Arctic Ocean climatic changes hydrography oceanography |
spellingShingle |
ocean currents Arctic Ocean climatic changes hydrography oceanography Baumann, Till M. Response of major modes of eastern Arctic Ocean variability to climate change |
topic_facet |
ocean currents Arctic Ocean climatic changes hydrography oceanography |
description |
Dissertation (Ph.D.) University of Alaska Fairbanks, 2019 The Arctic Ocean plays a central role in ongoing climate change, with sea ice loss being the most prominent indicator. Recent observations showed that Atlantic inflows play an increasingly important role in the demise of sea ice. This encroaching atlantification of the eastern Arctic Ocean impacts the mean state and the variability of hydrography and current dynamics throughout the basin. Among the most energetic modes of variability are the seasonal cycle and high frequency semidiurnal (∼12-hourly) dynamics in the tidal and inertial frequency band. Limited observations indicated a substantial increase of both, hydrographic seasonal cycles as well as semidiurnal current dynamics in the eastern Arctic over the last decade. Using a uniquely comprehensive data set from an array of six moorings deployed across the eastern Eurasian Basin (EB) continental slope along the 125°E meridian between 2013 and 2015 within the NABOS project, we assess the state of hydrographic seasonal cycles in the eastern EB. Results show a complex pattern of seasonality with a remarkably strong (∆T=1.4°C), deep reaching (∼600 m) temperature signal over the continental slope and large-scale seasonal displacements of isopycnal interfaces. Seasonally changing background conditions are also the main source of variability of semidiurnal frequency band currents: During winter, vigorous baroclinic tidal currents whose amplitudes by far exceed predictions follow the vertical evolution of the pycnocline. During summer, extensive open-water periods additionally lead to strong wind-driven inertial currents in the upper ocean, routinely exceeding 30 cm/s far offshore in the deep basin. In order to obtain an Arctic-wide perspective on the impact of baroclinic tidal currents, a pan-Arctic tidal current atlas has been developed that synthesizes all available observations from the last 20 years. This atlas allows for in-depth studies of regional baroclinic tidal current variability as well as for ... |
author2 |
Polyakov, Igor V. Bhatt, Uma S. Walsh, John E. Weingartner, Thomas J. |
format |
Doctoral or Postdoctoral Thesis |
author |
Baumann, Till M. |
author_facet |
Baumann, Till M. |
author_sort |
Baumann, Till M. |
title |
Response of major modes of eastern Arctic Ocean variability to climate change |
title_short |
Response of major modes of eastern Arctic Ocean variability to climate change |
title_full |
Response of major modes of eastern Arctic Ocean variability to climate change |
title_fullStr |
Response of major modes of eastern Arctic Ocean variability to climate change |
title_full_unstemmed |
Response of major modes of eastern Arctic Ocean variability to climate change |
title_sort |
response of major modes of eastern arctic ocean variability to climate change |
publishDate |
2019 |
url |
http://hdl.handle.net/11122/10886 |
geographic |
Arctic Arctic Ocean Fairbanks |
geographic_facet |
Arctic Arctic Ocean Fairbanks |
genre |
Arctic Arctic Ocean Climate change Sea ice Alaska |
genre_facet |
Arctic Arctic Ocean Climate change Sea ice Alaska |
op_relation |
http://hdl.handle.net/11122/10886 Department of Atmospheric Sciences |
_version_ |
1766313165189021696 |