2002: 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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ftciteseerx:oai:CiteSeerX.psu:10.1.1.160.7133 2023-05-15T14:52:27+02:00 2002: The NAO troposphere–stratosphere connection Maarten H. P. Ambaum Brian J. Hoskins The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.160.7133 http://www.met.rdg.ac.uk/~sws97mha/articles/jclim2002.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.160.7133 http://www.met.rdg.ac.uk/~sws97mha/articles/jclim2002.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.met.rdg.ac.uk/~sws97mha/articles/jclim2002.pdf text ftciteseerx 2016-01-07T15:43:07Z 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. 1. Text Arctic Iceland North Atlantic North Atlantic oscillation North Pole Unknown Arctic North Pole |
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ftciteseerx |
language |
English |
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. 1. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Maarten H. P. Ambaum Brian J. Hoskins |
spellingShingle |
Maarten H. P. Ambaum Brian J. Hoskins 2002: The NAO troposphere–stratosphere connection |
author_facet |
Maarten H. P. Ambaum Brian J. Hoskins |
author_sort |
Maarten H. P. Ambaum |
title |
2002: The NAO troposphere–stratosphere connection |
title_short |
2002: The NAO troposphere–stratosphere connection |
title_full |
2002: The NAO troposphere–stratosphere connection |
title_fullStr |
2002: The NAO troposphere–stratosphere connection |
title_full_unstemmed |
2002: The NAO troposphere–stratosphere connection |
title_sort |
2002: the nao troposphere–stratosphere connection |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.160.7133 http://www.met.rdg.ac.uk/~sws97mha/articles/jclim2002.pdf |
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_source |
http://www.met.rdg.ac.uk/~sws97mha/articles/jclim2002.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.160.7133 http://www.met.rdg.ac.uk/~sws97mha/articles/jclim2002.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766323694027669504 |