Determining North Atlantic meridional transport variability from pressure on the western boundary: A model investigation
In this paper, we investigate the possibility of determining North Atlantic meridional transport variability using pressure on the western boundary, focusing on the 42°N latitude of the Halifax WAVE array. We start by reviewing the theoretical foundations of this approach. Next, we present results f...
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2008
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ftunivnewcastle:oai:eprint.ncl.ac.uk:152723 2023-05-15T17:31:02+02:00 Determining North Atlantic meridional transport variability from pressure on the western boundary: A model investigation Bingham RJ Hughes CW 04-09-2008 application/pdf https://eprint.ncl.ac.uk/fulltext.aspx?url=152723/81ACB692-C7C0-4DA4-BFE1-281147245D13.pdf&pub_id=152723 unknown American Geophysical Union Journal of Geophysical Research, 04-09-2008 Article 2008 ftunivnewcastle 2020-06-11T23:02:32Z In this paper, we investigate the possibility of determining North Atlantic meridional transport variability using pressure on the western boundary, focusing on the 42°N latitude of the Halifax WAVE array. We start by reviewing the theoretical foundations of this approach. Next, we present results from a model analysis, both statistical and dynamic, that demonstrate the feasibility of the approach. We consider how well we can quantify the meridional transport variability at 42°N given complete knowledge of bottom pressure across the basin and to what degree this quantification is degraded by first ignoring the effect of intervening topography and then by using only bottom pressure on the western boundary. We find that for periods of greater than 1 year, we can recover more than 90% of the variability of the main overturning cell at 42°N using only the western boundary pressure, provided that we remove the depth-averaged boundary pressure signal. This signal arises from a basin mode of bottom pressure variability, which has power at all time scales, but that does not in truth have a meridional transport signal associated with it, and from the geostrophic depth-independent compensation of the Ekman transport. An additional benefit of the removal of the depth-averaged pressure is that this high-frequency Ekman signal, which is essentially noise as far as monitoring the meridional overturning circulation for climatically important changes is concerned, is clearly separated from other modes. Article in Journal/Newspaper North Atlantic Newcastle University Library ePrints Service |
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Newcastle University Library ePrints Service |
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ftunivnewcastle |
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description |
In this paper, we investigate the possibility of determining North Atlantic meridional transport variability using pressure on the western boundary, focusing on the 42°N latitude of the Halifax WAVE array. We start by reviewing the theoretical foundations of this approach. Next, we present results from a model analysis, both statistical and dynamic, that demonstrate the feasibility of the approach. We consider how well we can quantify the meridional transport variability at 42°N given complete knowledge of bottom pressure across the basin and to what degree this quantification is degraded by first ignoring the effect of intervening topography and then by using only bottom pressure on the western boundary. We find that for periods of greater than 1 year, we can recover more than 90% of the variability of the main overturning cell at 42°N using only the western boundary pressure, provided that we remove the depth-averaged boundary pressure signal. This signal arises from a basin mode of bottom pressure variability, which has power at all time scales, but that does not in truth have a meridional transport signal associated with it, and from the geostrophic depth-independent compensation of the Ekman transport. An additional benefit of the removal of the depth-averaged pressure is that this high-frequency Ekman signal, which is essentially noise as far as monitoring the meridional overturning circulation for climatically important changes is concerned, is clearly separated from other modes. |
format |
Article in Journal/Newspaper |
author |
Bingham RJ Hughes CW |
spellingShingle |
Bingham RJ Hughes CW Determining North Atlantic meridional transport variability from pressure on the western boundary: A model investigation |
author_facet |
Bingham RJ Hughes CW |
author_sort |
Bingham RJ |
title |
Determining North Atlantic meridional transport variability from pressure on the western boundary: A model investigation |
title_short |
Determining North Atlantic meridional transport variability from pressure on the western boundary: A model investigation |
title_full |
Determining North Atlantic meridional transport variability from pressure on the western boundary: A model investigation |
title_fullStr |
Determining North Atlantic meridional transport variability from pressure on the western boundary: A model investigation |
title_full_unstemmed |
Determining North Atlantic meridional transport variability from pressure on the western boundary: A model investigation |
title_sort |
determining north atlantic meridional transport variability from pressure on the western boundary: a model investigation |
publisher |
American Geophysical Union |
publishDate |
2008 |
url |
https://eprint.ncl.ac.uk/fulltext.aspx?url=152723/81ACB692-C7C0-4DA4-BFE1-281147245D13.pdf&pub_id=152723 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Journal of Geophysical Research, 04-09-2008 |
_version_ |
1766128346433847296 |