On the influence of zonal gravity wave distributions on the Southern Hemisphere winter circulation
A mechanistic global circulation model is used to simulate the Southern Hemisphere stratospheric, mesospheric, and lower thermospheric circulation during austral winter. The model includes a gravity wave (GW) parameterization that is initiated by prescribed 2-D fields of GW parameters in the troposp...
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ftcopernicus:oai:publications.copernicus.org:angeo56998 2023-05-15T13:54:27+02:00 On the influence of zonal gravity wave distributions on the Southern Hemisphere winter circulation Lilienthal, Friederike Jacobi, Christoph Schmidt, Torsten Torre, Alejandro Alexander, Peter 2018-09-27 application/pdf https://doi.org/10.5194/angeo-35-785-2017 https://angeo.copernicus.org/articles/35/785/2017/ eng eng doi:10.5194/angeo-35-785-2017 https://angeo.copernicus.org/articles/35/785/2017/ eISSN: 1432-0576 Text 2018 ftcopernicus https://doi.org/10.5194/angeo-35-785-2017 2020-07-20T16:23:40Z A mechanistic global circulation model is used to simulate the Southern Hemisphere stratospheric, mesospheric, and lower thermospheric circulation during austral winter. The model includes a gravity wave (GW) parameterization that is initiated by prescribed 2-D fields of GW parameters in the troposphere. These are based on observations of GW potential energy calculated using GPS radio occultations and show enhanced GW activity east of the Andes and around the Antarctic. In order to detect the influence of an observation-based and thus realistic 2-D GW distribution on the middle atmosphere circulation, we perform model experiments with zonal mean and 2-D GW initialization, and additionally with and without forcing of stationary planetary waves (SPWs) at the lower boundary of the model. As a result, we find additional forcing of SPWs in the stratosphere, a weaker zonal wind jet in the mesosphere, cooling of the mesosphere and warming near the mesopause above the jet. SPW wavenumber 1 (SPW1) amplitudes are generally increased by about 10 % when GWs are introduced being longitudinally dependent. However, at the upper part of the zonal wind jet, SPW1 in zonal wind and GW acceleration are out of phase, which reduces the amplitudes there. Text Antarc* Antarctic Copernicus Publications: E-Journals Antarctic Austral The Antarctic Annales Geophysicae 35 4 785 798 |
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Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
A mechanistic global circulation model is used to simulate the Southern Hemisphere stratospheric, mesospheric, and lower thermospheric circulation during austral winter. The model includes a gravity wave (GW) parameterization that is initiated by prescribed 2-D fields of GW parameters in the troposphere. These are based on observations of GW potential energy calculated using GPS radio occultations and show enhanced GW activity east of the Andes and around the Antarctic. In order to detect the influence of an observation-based and thus realistic 2-D GW distribution on the middle atmosphere circulation, we perform model experiments with zonal mean and 2-D GW initialization, and additionally with and without forcing of stationary planetary waves (SPWs) at the lower boundary of the model. As a result, we find additional forcing of SPWs in the stratosphere, a weaker zonal wind jet in the mesosphere, cooling of the mesosphere and warming near the mesopause above the jet. SPW wavenumber 1 (SPW1) amplitudes are generally increased by about 10 % when GWs are introduced being longitudinally dependent. However, at the upper part of the zonal wind jet, SPW1 in zonal wind and GW acceleration are out of phase, which reduces the amplitudes there. |
format |
Text |
author |
Lilienthal, Friederike Jacobi, Christoph Schmidt, Torsten Torre, Alejandro Alexander, Peter |
spellingShingle |
Lilienthal, Friederike Jacobi, Christoph Schmidt, Torsten Torre, Alejandro Alexander, Peter On the influence of zonal gravity wave distributions on the Southern Hemisphere winter circulation |
author_facet |
Lilienthal, Friederike Jacobi, Christoph Schmidt, Torsten Torre, Alejandro Alexander, Peter |
author_sort |
Lilienthal, Friederike |
title |
On the influence of zonal gravity wave distributions on the Southern Hemisphere winter circulation |
title_short |
On the influence of zonal gravity wave distributions on the Southern Hemisphere winter circulation |
title_full |
On the influence of zonal gravity wave distributions on the Southern Hemisphere winter circulation |
title_fullStr |
On the influence of zonal gravity wave distributions on the Southern Hemisphere winter circulation |
title_full_unstemmed |
On the influence of zonal gravity wave distributions on the Southern Hemisphere winter circulation |
title_sort |
on the influence of zonal gravity wave distributions on the southern hemisphere winter circulation |
publishDate |
2018 |
url |
https://doi.org/10.5194/angeo-35-785-2017 https://angeo.copernicus.org/articles/35/785/2017/ |
geographic |
Antarctic Austral The Antarctic |
geographic_facet |
Antarctic Austral The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
eISSN: 1432-0576 |
op_relation |
doi:10.5194/angeo-35-785-2017 https://angeo.copernicus.org/articles/35/785/2017/ |
op_doi |
https://doi.org/10.5194/angeo-35-785-2017 |
container_title |
Annales Geophysicae |
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35 |
container_issue |
4 |
container_start_page |
785 |
op_container_end_page |
798 |
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1766260322306359296 |