Numerical study and remote sensing of the convection, restratification and mesoscale processes in the Labrador Sea and their implications on the subpolar North Atlantic warming

This dissertation focuses on quantifying the physical processes in the Labrador Sea, such as wintertime deep convections, subsequent restratification, and the mesoscale eddy activities. The Labrador Sea is one of the areas where deep ocean is warming since 1998, so it has an implication on the recen...

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Main Author: Zhang, Weiwei
Format: Thesis
Language:unknown
Published: University of Delaware 2015
Subjects:
Online Access:http://udspace.udel.edu/handle/19716/17518
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record_format openpolar
spelling ftunivdelaware:oai:udspace.udel.edu:19716/17518 2023-06-11T04:12:23+02:00 Numerical study and remote sensing of the convection, restratification and mesoscale processes in the Labrador Sea and their implications on the subpolar North Atlantic warming Zhang, Weiwei 2015 application/pdf http://udspace.udel.edu/handle/19716/17518 unknown University of Delaware http://search.proquest.com/docview/1767224377?accountid=10457 945072744 http://udspace.udel.edu/handle/19716/17518 Labrador Sea Convection (Oceanography) -- Labrador Sea Global warming -- Labrador Sea Global warming -- North Atlantic Ocean Thesis 2015 ftunivdelaware 2023-05-01T12:56:09Z This dissertation focuses on quantifying the physical processes in the Labrador Sea, such as wintertime deep convections, subsequent restratification, and the mesoscale eddy activities. The Labrador Sea is one of the areas where deep ocean is warming since 1998, so it has an implication on the recent global surface warming slow-down, which is also termed the global warming “hiatus”. The restratification after the 2008 deep convection is studied using regional ocean model. The modeled mixed layer depth during wintertime resembles the ARGO observed mixed layer very well, and the lateral heat flux during the subsequent restratification is in line with observations. The Irminger Rings (IRs) are reproduced with fresher caps, and they are identified and tracked automatically. The model underestimates both the number of IRs into the convection area and the heat they carry. The underestimation is most likely caused by the errors in the direction of the West Greenland currents (WGC) in the model, which causes more IRs propagating westward. Yet, the model still observed three eddies propagating into the convection area during restratification phase in 2008, and they contribute from 1 to 4% of the total heat regain during central Labrador Sea restratification. Then a merged along track altimeter dataset is used to study the variability of eddy kinetic energy (EKE) in the Labrador Sea from 1993 to 2012. The WGC EKE propagates far into the central Labrador Sea during occasional years, and its annual cycle magnitude declines. The decreasing annual cycle is related to the central basin convections, while the WGC EKE strengths is controlled by a low frequency variation of the wind stress curl, which is related to the subpolar gyre (SPG) circulation. Finally, the subpolar North Atlantic (SPNA) warming during the recent global warming slow-down is studied by separately investigating the subsurface warming of the eastern and western SPNA. Temperature decompositions indicate buoyancy domination in the west, and wind stress forcing ... Thesis Greenland Labrador Sea North Atlantic The University of Delaware Library Institutional Repository Central Basin ENVELOPE(43.000,43.000,73.500,73.500) Curl ENVELOPE(-63.071,-63.071,-70.797,-70.797) Greenland
institution Open Polar
collection The University of Delaware Library Institutional Repository
op_collection_id ftunivdelaware
language unknown
topic Labrador Sea
Convection (Oceanography) -- Labrador Sea
Global warming -- Labrador Sea
Global warming -- North Atlantic Ocean
spellingShingle Labrador Sea
Convection (Oceanography) -- Labrador Sea
Global warming -- Labrador Sea
Global warming -- North Atlantic Ocean
Zhang, Weiwei
Numerical study and remote sensing of the convection, restratification and mesoscale processes in the Labrador Sea and their implications on the subpolar North Atlantic warming
topic_facet Labrador Sea
Convection (Oceanography) -- Labrador Sea
Global warming -- Labrador Sea
Global warming -- North Atlantic Ocean
description This dissertation focuses on quantifying the physical processes in the Labrador Sea, such as wintertime deep convections, subsequent restratification, and the mesoscale eddy activities. The Labrador Sea is one of the areas where deep ocean is warming since 1998, so it has an implication on the recent global surface warming slow-down, which is also termed the global warming “hiatus”. The restratification after the 2008 deep convection is studied using regional ocean model. The modeled mixed layer depth during wintertime resembles the ARGO observed mixed layer very well, and the lateral heat flux during the subsequent restratification is in line with observations. The Irminger Rings (IRs) are reproduced with fresher caps, and they are identified and tracked automatically. The model underestimates both the number of IRs into the convection area and the heat they carry. The underestimation is most likely caused by the errors in the direction of the West Greenland currents (WGC) in the model, which causes more IRs propagating westward. Yet, the model still observed three eddies propagating into the convection area during restratification phase in 2008, and they contribute from 1 to 4% of the total heat regain during central Labrador Sea restratification. Then a merged along track altimeter dataset is used to study the variability of eddy kinetic energy (EKE) in the Labrador Sea from 1993 to 2012. The WGC EKE propagates far into the central Labrador Sea during occasional years, and its annual cycle magnitude declines. The decreasing annual cycle is related to the central basin convections, while the WGC EKE strengths is controlled by a low frequency variation of the wind stress curl, which is related to the subpolar gyre (SPG) circulation. Finally, the subpolar North Atlantic (SPNA) warming during the recent global warming slow-down is studied by separately investigating the subsurface warming of the eastern and western SPNA. Temperature decompositions indicate buoyancy domination in the west, and wind stress forcing ...
format Thesis
author Zhang, Weiwei
author_facet Zhang, Weiwei
author_sort Zhang, Weiwei
title Numerical study and remote sensing of the convection, restratification and mesoscale processes in the Labrador Sea and their implications on the subpolar North Atlantic warming
title_short Numerical study and remote sensing of the convection, restratification and mesoscale processes in the Labrador Sea and their implications on the subpolar North Atlantic warming
title_full Numerical study and remote sensing of the convection, restratification and mesoscale processes in the Labrador Sea and their implications on the subpolar North Atlantic warming
title_fullStr Numerical study and remote sensing of the convection, restratification and mesoscale processes in the Labrador Sea and their implications on the subpolar North Atlantic warming
title_full_unstemmed Numerical study and remote sensing of the convection, restratification and mesoscale processes in the Labrador Sea and their implications on the subpolar North Atlantic warming
title_sort numerical study and remote sensing of the convection, restratification and mesoscale processes in the labrador sea and their implications on the subpolar north atlantic warming
publisher University of Delaware
publishDate 2015
url http://udspace.udel.edu/handle/19716/17518
long_lat ENVELOPE(43.000,43.000,73.500,73.500)
ENVELOPE(-63.071,-63.071,-70.797,-70.797)
geographic Central Basin
Curl
Greenland
geographic_facet Central Basin
Curl
Greenland
genre Greenland
Labrador Sea
North Atlantic
genre_facet Greenland
Labrador Sea
North Atlantic
op_relation http://search.proquest.com/docview/1767224377?accountid=10457
945072744
http://udspace.udel.edu/handle/19716/17518
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