Numerical studies of major and minor stratospheric warmings caused by orographic forcing
A primitive equation spectral model using spherical harmonics is formulated to study dynamic interactions between the troposphere and stratosphere in association with sudden stratospheric warmings. Using sigma coordinates for five tropospheric layers and log-pressure coordinates for 26 stratospheric...
Main Authors: | , , |
---|---|
Format: | Other/Unknown Material |
Language: | unknown |
Published: |
1983
|
Subjects: | |
Online Access: | http://ntrs.nasa.gov/search.jsp?R=19830063490 |
id |
ftnasantrs:oai:casi.ntrs.nasa.gov:19830063490 |
---|---|
record_format |
openpolar |
spelling |
ftnasantrs:oai:casi.ntrs.nasa.gov:19830063490 2023-05-15T18:02:14+02:00 Numerical studies of major and minor stratospheric warmings caused by orographic forcing Koermer, J. P. Kasahara, A. Kao, S. K. Unclassified, Unlimited, Publicly available Jun 1, 1983 http://ntrs.nasa.gov/search.jsp?R=19830063490 unknown http://ntrs.nasa.gov/search.jsp?R=19830063490 Accession ID: 83A44708 Copyright Other Sources 47 Journal of the Atmospheric Sciences; 40; June 198 1983 ftnasantrs 2012-02-15T15:32:21Z A primitive equation spectral model using spherical harmonics is formulated to study dynamic interactions between the troposphere and stratosphere in association with sudden stratospheric warmings. Using sigma coordinates for five tropospheric layers and log-pressure coordinates for 26 stratospheric and mesospheric layers, separate model equations for each system are combined to form single matrix governing equations. The gradual introduction of large scale topography to balanced initial states representative of observed mean winter conditions in the Northern Hemisphere is used for the generation of planetary waves during 40-day time integrations. Results of these integrations indicate that stratospheric warmings can be simulated by this orographic forcing and that mean momentum flux divergence due to zonal mean motion appears to be an essential mechanism of these simulated sudden warmings. It was found that the strength of the polar night jet can be a determining factor whether a warming becomes 'major' or 'minor'. Other/Unknown Material polar night NASA Technical Reports Server (NTRS) |
institution |
Open Polar |
collection |
NASA Technical Reports Server (NTRS) |
op_collection_id |
ftnasantrs |
language |
unknown |
topic |
47 |
spellingShingle |
47 Koermer, J. P. Kasahara, A. Kao, S. K. Numerical studies of major and minor stratospheric warmings caused by orographic forcing |
topic_facet |
47 |
description |
A primitive equation spectral model using spherical harmonics is formulated to study dynamic interactions between the troposphere and stratosphere in association with sudden stratospheric warmings. Using sigma coordinates for five tropospheric layers and log-pressure coordinates for 26 stratospheric and mesospheric layers, separate model equations for each system are combined to form single matrix governing equations. The gradual introduction of large scale topography to balanced initial states representative of observed mean winter conditions in the Northern Hemisphere is used for the generation of planetary waves during 40-day time integrations. Results of these integrations indicate that stratospheric warmings can be simulated by this orographic forcing and that mean momentum flux divergence due to zonal mean motion appears to be an essential mechanism of these simulated sudden warmings. It was found that the strength of the polar night jet can be a determining factor whether a warming becomes 'major' or 'minor'. |
format |
Other/Unknown Material |
author |
Koermer, J. P. Kasahara, A. Kao, S. K. |
author_facet |
Koermer, J. P. Kasahara, A. Kao, S. K. |
author_sort |
Koermer, J. P. |
title |
Numerical studies of major and minor stratospheric warmings caused by orographic forcing |
title_short |
Numerical studies of major and minor stratospheric warmings caused by orographic forcing |
title_full |
Numerical studies of major and minor stratospheric warmings caused by orographic forcing |
title_fullStr |
Numerical studies of major and minor stratospheric warmings caused by orographic forcing |
title_full_unstemmed |
Numerical studies of major and minor stratospheric warmings caused by orographic forcing |
title_sort |
numerical studies of major and minor stratospheric warmings caused by orographic forcing |
publishDate |
1983 |
url |
http://ntrs.nasa.gov/search.jsp?R=19830063490 |
op_coverage |
Unclassified, Unlimited, Publicly available |
genre |
polar night |
genre_facet |
polar night |
op_source |
Other Sources |
op_relation |
http://ntrs.nasa.gov/search.jsp?R=19830063490 Accession ID: 83A44708 |
op_rights |
Copyright |
_version_ |
1766172032041484288 |