The NAO troposphere–stratosphere connection
Using monthly mean data, daily data, and theoretical arguments, relationships between surface pressure variations associated with the North Atlantic Oscillation (NAO), tropopause height, and the strength of the stratospheric vortex are established. An increase in the NAO index leads to a stronger st...
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American Meteorological Society
2002
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ftunivreading:oai:centaur.reading.ac.uk:7701 2024-09-09T19:21:33+00:00 The NAO troposphere–stratosphere connection Ambaum, Maarten H. P. Hoskins, Brian J. 2002-07 https://centaur.reading.ac.uk/7701/ unknown American Meteorological Society Ambaum, M. H. P. <https://centaur.reading.ac.uk/view/creators/90000224.html> orcid:0000-0002-6824-8083 and Hoskins, B. J. <https://centaur.reading.ac.uk/view/creators/90000043.html> (2002) The NAO troposphere–stratosphere connection. Journal of Climate, 15 (14). pp. 1969-1978. ISSN 1520-0442 doi: https://doi.org/10.1175/1520-0442(2002)015<1969:TNTSC>2.0.CO;2 <https://doi.org/10.1175/1520-0442(2002)015<1969:TNTSC>2.0.CO;2> Article PeerReviewed 2002 ftunivreading https://doi.org/10.1175/1520-0442(2002)015<1969:TNTSC>2.0.CO;2 2024-06-18T14:20:05Z Using monthly mean data, daily data, and theoretical arguments, relationships between surface pressure variations associated with the North Atlantic Oscillation (NAO), tropopause height, and the strength of the stratospheric vortex are established. An increase in the NAO index leads to a stronger stratospheric vortex, about 4 days later, as a result of increased equatorward refraction of upward-propagating Rossby waves. At tropopause level the effects of the enhanced NAO index and stratospheric polar vortex are opposite, resulting in a lower tropopause over Iceland and a higher tropopause over the Arctic. The raising of the Arctic tropopause leads to a stretching and spinup of the tropospheric column and is therefore associated with a lowering of the surface pressure near the North Pole. For monthly mean data it is found that a standard deviation increase in the NAO index is associated with a 10% increase in the strength of the stratospheric vortex, as measured by potential vorticity at 500 K. A simple theoretical model predicts that this is associated with about 300-m elevation of the Arctic tropopause, as is observed, and a 5-hPa lowering of the surface pressure at the North Pole. The effects of the spinup of the tropospheric column may project on the NAO pattern so that the stratosphere acts as an integrator of the NAO index. Article in Journal/Newspaper Arctic Iceland North Atlantic North Atlantic oscillation North Pole CentAUR: Central Archive at the University of Reading Arctic North Pole Biology Letters 12 11 20160277 |
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Open Polar |
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CentAUR: Central Archive at the University of Reading |
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ftunivreading |
language |
unknown |
description |
Using monthly mean data, daily data, and theoretical arguments, relationships between surface pressure variations associated with the North Atlantic Oscillation (NAO), tropopause height, and the strength of the stratospheric vortex are established. An increase in the NAO index leads to a stronger stratospheric vortex, about 4 days later, as a result of increased equatorward refraction of upward-propagating Rossby waves. At tropopause level the effects of the enhanced NAO index and stratospheric polar vortex are opposite, resulting in a lower tropopause over Iceland and a higher tropopause over the Arctic. The raising of the Arctic tropopause leads to a stretching and spinup of the tropospheric column and is therefore associated with a lowering of the surface pressure near the North Pole. For monthly mean data it is found that a standard deviation increase in the NAO index is associated with a 10% increase in the strength of the stratospheric vortex, as measured by potential vorticity at 500 K. A simple theoretical model predicts that this is associated with about 300-m elevation of the Arctic tropopause, as is observed, and a 5-hPa lowering of the surface pressure at the North Pole. The effects of the spinup of the tropospheric column may project on the NAO pattern so that the stratosphere acts as an integrator of the NAO index. |
format |
Article in Journal/Newspaper |
author |
Ambaum, Maarten H. P. Hoskins, Brian J. |
spellingShingle |
Ambaum, Maarten H. P. Hoskins, Brian J. The NAO troposphere–stratosphere connection |
author_facet |
Ambaum, Maarten H. P. Hoskins, Brian J. |
author_sort |
Ambaum, Maarten H. P. |
title |
The NAO troposphere–stratosphere connection |
title_short |
The NAO troposphere–stratosphere connection |
title_full |
The NAO troposphere–stratosphere connection |
title_fullStr |
The NAO troposphere–stratosphere connection |
title_full_unstemmed |
The NAO troposphere–stratosphere connection |
title_sort |
nao troposphere–stratosphere connection |
publisher |
American Meteorological Society |
publishDate |
2002 |
url |
https://centaur.reading.ac.uk/7701/ |
geographic |
Arctic North Pole |
geographic_facet |
Arctic North Pole |
genre |
Arctic Iceland North Atlantic North Atlantic oscillation North Pole |
genre_facet |
Arctic Iceland North Atlantic North Atlantic oscillation North Pole |
op_relation |
Ambaum, M. H. P. <https://centaur.reading.ac.uk/view/creators/90000224.html> orcid:0000-0002-6824-8083 and Hoskins, B. J. <https://centaur.reading.ac.uk/view/creators/90000043.html> (2002) The NAO troposphere–stratosphere connection. Journal of Climate, 15 (14). pp. 1969-1978. ISSN 1520-0442 doi: https://doi.org/10.1175/1520-0442(2002)015<1969:TNTSC>2.0.CO;2 <https://doi.org/10.1175/1520-0442(2002)015<1969:TNTSC>2.0.CO;2> |
op_doi |
https://doi.org/10.1175/1520-0442(2002)015<1969:TNTSC>2.0.CO;2 |
container_title |
Biology Letters |
container_volume |
12 |
container_issue |
11 |
container_start_page |
20160277 |
_version_ |
1809761754742259712 |