skip to content
The upper limb of the North Atlantic overturning circulation : investigation of the subtropical-subpolar gyre exchange and Subpolar Mode Water Preview this item
ClosePreview this item
Checking...

The upper limb of the North Atlantic overturning circulation : investigation of the subtropical-subpolar gyre exchange and Subpolar Mode Water

Author: Elena Brambilla
Publisher: 2006.
Dissertation: Ph. D. University of California, San Diego 2006
Edition/Format:   Thesis/dissertation : Document : Thesis/dissertation : eBook   Computer File : English
Summary:
Two aspects of the upper limb of the North Atlantic overturning circulation are studied: 1) surface drifter exchange between the subtropical and the subpolar gyres; and 2) characterization of the properties and formation of Subpolar Mode Waters (SPMW). With respect to the first, just one out of 273 drifters (drogued at 15 m) in the Gulf Stream region from 1990 to 2002, moved from subtropical to subpolar latitudes.  Read more...
Rating:

(not yet rated) 0 with reviews - Be the first.

Find a copy online

Links to this item

Find a copy in the library

&AllPage.SpinnerRetrieving; Finding libraries that hold this item...

Details

Genre/Form: Dissertations, Academic
Material Type: Document, Thesis/dissertation, Internet resource
Document Type: Internet Resource, Computer File
All Authors / Contributors: Elena Brambilla
OCLC Number: 85373730
Notes: Title from first page of PDF file (viewed December 12, 2006).
Available via ProQuest Digital Dissertations.
Vita.
Description: 1 online resource (xiv, 148 pages) : PDF file
Details: Mode of access: World Wide Web.
Responsibility: by Elena Brambilla.
More information:

Abstract:

Two aspects of the upper limb of the North Atlantic overturning circulation are studied: 1) surface drifter exchange between the subtropical and the subpolar gyres; and 2) characterization of the properties and formation of Subpolar Mode Waters (SPMW). With respect to the first, just one out of 273 drifters (drogued at 15 m) in the Gulf Stream region from 1990 to 2002, moved from subtropical to subpolar latitudes. Most of the drifters recirculated in the subtropical gyre without crossing the inter-gyre edge. This result was surprising because of the known transport of upper ocean water from the subtropical to the subpolar gyre. We suggest that undersampling and inadequate drifter life time lead to an underestimate the northward flow. Moreover, the Ekman flow and the eddy contribution affect the surface trajectories in opposite direction, nearly canceling each other. The description of the properties of the SPMW and the analysis of its formation aim at better describing the warm and salty pathway that supplies water to the regions of dense water formation (Labrador and Nordic Seas). Lagrangian data (surface drifters and isopycnal floats) combined with historical hydrographic data show that each branch of the North Atlantic Current (NAC) in the eastern subpolar gyre is characterized by its own sequence of SPMW that increases in density following the downstream flow. Furthermore, since the branches of the NAC have a dominant northeastward direction, the newly observed distribution of SPMW, combined with the new streamfunctions calculated here, do not support the original hypothesis of (McCartney and Talley, 1982) of a smooth, cyclonic pathway for SPMW around the subpolar gyre. The transformation and the formation of SPMW are then investigated in terms of the diapycnal flux driven by buoyancy flux. We show that SPMW is transformed to increasingly dense SPMW along the major branches of the NAC. The continuous transformation of SPMW is not constant in density space, leading to ``formation'' (destruction) of SPMW. However, since the SPMWs are shown to be confined within the mixed layer, we interpret the SPMW formation as loss by entrainment to the dense overflows through Denmark Strait and Iceland_Scotland Ridge.

Reviews

User-contributed reviews
Retrieving GoodReads reviews...
Retrieving DOGObooks reviews...

Tags

Be the first.
Confirm this request

You may have already requested this item. Please select Ok if you would like to proceed with this request anyway.

Linked Data


Primary Entity

<http://www.worldcat.org/oclc/85373730> # The upper limb of the North Atlantic overturning circulation : investigation of the subtropical-subpolar gyre exchange and Subpolar Mode Water
    a pto:Web_document, bgn:Thesis, schema:Book, schema:MediaObject, schema:CreativeWork ;
   bgn:inSupportOf "" ;
   library:oclcnum "85373730" ;
   schema:creator <http://experiment.worldcat.org/entity/work/data/69346031#Person/brambilla_elena_1976> ; # Elena Brambilla
   schema:datePublished "2006" ;
   schema:description "Two aspects of the upper limb of the North Atlantic overturning circulation are studied: 1) surface drifter exchange between the subtropical and the subpolar gyres; and 2) characterization of the properties and formation of Subpolar Mode Waters (SPMW). With respect to the first, just one out of 273 drifters (drogued at 15 m) in the Gulf Stream region from 1990 to 2002, moved from subtropical to subpolar latitudes. Most of the drifters recirculated in the subtropical gyre without crossing the inter-gyre edge. This result was surprising because of the known transport of upper ocean water from the subtropical to the subpolar gyre. We suggest that undersampling and inadequate drifter life time lead to an underestimate the northward flow. Moreover, the Ekman flow and the eddy contribution affect the surface trajectories in opposite direction, nearly canceling each other. The description of the properties of the SPMW and the analysis of its formation aim at better describing the warm and salty pathway that supplies water to the regions of dense water formation (Labrador and Nordic Seas). Lagrangian data (surface drifters and isopycnal floats) combined with historical hydrographic data show that each branch of the North Atlantic Current (NAC) in the eastern subpolar gyre is characterized by its own sequence of SPMW that increases in density following the downstream flow. Furthermore, since the branches of the NAC have a dominant northeastward direction, the newly observed distribution of SPMW, combined with the new streamfunctions calculated here, do not support the original hypothesis of (McCartney and Talley, 1982) of a smooth, cyclonic pathway for SPMW around the subpolar gyre. The transformation and the formation of SPMW are then investigated in terms of the diapycnal flux driven by buoyancy flux. We show that SPMW is transformed to increasingly dense SPMW along the major branches of the NAC. The continuous transformation of SPMW is not constant in density space, leading to ``formation'' (destruction) of SPMW. However, since the SPMWs are shown to be confined within the mixed layer, we interpret the SPMW formation as loss by entrainment to the dense overflows through Denmark Strait and Iceland_Scotland Ridge."@en ;
   schema:exampleOfWork <http://worldcat.org/entity/work/id/69346031> ;
   schema:genre "Dissertations, Academic"@en ;
   schema:inLanguage "en" ;
   schema:name "The upper limb of the North Atlantic overturning circulation : investigation of the subtropical-subpolar gyre exchange and Subpolar Mode Water"@en ;
   schema:productID "85373730" ;
   schema:publication <http://www.worldcat.org/title/-/oclc/85373730#PublicationEvent/2006> ;
   schema:url <http://escholarship.org/uc/item/59m32073> ;
   schema:url <http://wwwlib.umi.com/cr/fullcit?p3237551> ;
   wdrs:describedby <http://www.worldcat.org/title/-/oclc/85373730> ;
    .


Related Entities

<http://experiment.worldcat.org/entity/work/data/69346031#Person/brambilla_elena_1976> # Elena Brambilla
    a schema:Person ;
   schema:birthDate "1976" ;
   schema:familyName "Brambilla" ;
   schema:givenName "Elena" ;
   schema:name "Elena Brambilla" ;
    .

<http://www.worldcat.org/title/-/oclc/85373730>
    a genont:InformationResource, genont:ContentTypeGenericResource ;
   schema:about <http://www.worldcat.org/oclc/85373730> ; # The upper limb of the North Atlantic overturning circulation : investigation of the subtropical-subpolar gyre exchange and Subpolar Mode Water
   schema:dateModified "2018-11-09" ;
   void:inDataset <http://purl.oclc.org/dataset/WorldCat> ;
    .


Content-negotiable representations

Close Window

Please sign in to WorldCat 

Don't have an account? You can easily create a free account.