Regional to global evolution of impacts of parameterized mountain-wave drag in the lower stratosphere
Mountain ranges are regional features on Earth, as are the regions of mountain-wave drag (MWD) exerted by dissipating atmospheric gravity waves generated by flow over them. However, these regional drags have significant global- or zonal-mean impacts on Earth's atmospheric general circulation (e...
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Online Access: | https://doi.org/10.1175/JCLI-D-19-0076.1 |
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ftncar:oai:drupal-site.org:articles_23254 2024-04-28T08:31:59+00:00 Regional to global evolution of impacts of parameterized mountain-wave drag in the lower stratosphere Kruse, Christopher G. (author) 2020-04 https://doi.org/10.1175/JCLI-D-19-0076.1 en eng Journal of Climate--J. Climate--0894-8755--1520-0442 articles:23254 ark:/85065/d7445qp9 doi:10.1175/JCLI-D-19-0076.1 Copyright 2020 American Meteorological Society (AMS). article Text 2020 ftncar https://doi.org/10.1175/JCLI-D-19-0076.1 2024-04-04T17:35:13Z Mountain ranges are regional features on Earth, as are the regions of mountain-wave drag (MWD) exerted by dissipating atmospheric gravity waves generated by flow over them. However, these regional drags have significant global- or zonal-mean impacts on Earth's atmospheric general circulation (e.g., slowing of the polar night jet). The objective of this work is to understand the regional to global evolution of these impacts. The approach is to track the evolution of MWD-generated potential vorticity (PV) over the winter using the Whole Atmosphere Community Climate Model (WACCM). Within an ensemble of winter-long runs with and without MWD, lower-stratospheric PV is generated over mountains and advected downstream, generating large-scale PV banners. These PV banners are diffused but survive this diffusion and are reinforced over downstream mountain ranges, accumulating into zonal-mean or global features within WACCM. A simple 2D model representing sources, advection, and diffusion of "passive PV" recreates the salient features in the WACCM results, suggesting the winter-long evolution of MWD-generated PV can be crudely understood in terms of horizontal advection and diffusion within a global vortex. In the Northern Hemisphere, cyclonic, equatorward PV banners accumulate zonally into a single zonally symmetric positive PV anomaly. The anticyclonic, poleward PV banners also accumulate into a zonally symmetric feature, but then diffuse over the North Pole into a negative PV polar cap. In the Southern Hemisphere, the same processes are at work, though the different geographic configuration of mountain ranges leads to different patterns of impacts. 1852977 Article in Journal/Newspaper North Pole polar night OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Journal of Climate 33 8 3093 3106 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
Mountain ranges are regional features on Earth, as are the regions of mountain-wave drag (MWD) exerted by dissipating atmospheric gravity waves generated by flow over them. However, these regional drags have significant global- or zonal-mean impacts on Earth's atmospheric general circulation (e.g., slowing of the polar night jet). The objective of this work is to understand the regional to global evolution of these impacts. The approach is to track the evolution of MWD-generated potential vorticity (PV) over the winter using the Whole Atmosphere Community Climate Model (WACCM). Within an ensemble of winter-long runs with and without MWD, lower-stratospheric PV is generated over mountains and advected downstream, generating large-scale PV banners. These PV banners are diffused but survive this diffusion and are reinforced over downstream mountain ranges, accumulating into zonal-mean or global features within WACCM. A simple 2D model representing sources, advection, and diffusion of "passive PV" recreates the salient features in the WACCM results, suggesting the winter-long evolution of MWD-generated PV can be crudely understood in terms of horizontal advection and diffusion within a global vortex. In the Northern Hemisphere, cyclonic, equatorward PV banners accumulate zonally into a single zonally symmetric positive PV anomaly. The anticyclonic, poleward PV banners also accumulate into a zonally symmetric feature, but then diffuse over the North Pole into a negative PV polar cap. In the Southern Hemisphere, the same processes are at work, though the different geographic configuration of mountain ranges leads to different patterns of impacts. 1852977 |
author2 |
Kruse, Christopher G. (author) |
format |
Article in Journal/Newspaper |
title |
Regional to global evolution of impacts of parameterized mountain-wave drag in the lower stratosphere |
spellingShingle |
Regional to global evolution of impacts of parameterized mountain-wave drag in the lower stratosphere |
title_short |
Regional to global evolution of impacts of parameterized mountain-wave drag in the lower stratosphere |
title_full |
Regional to global evolution of impacts of parameterized mountain-wave drag in the lower stratosphere |
title_fullStr |
Regional to global evolution of impacts of parameterized mountain-wave drag in the lower stratosphere |
title_full_unstemmed |
Regional to global evolution of impacts of parameterized mountain-wave drag in the lower stratosphere |
title_sort |
regional to global evolution of impacts of parameterized mountain-wave drag in the lower stratosphere |
publishDate |
2020 |
url |
https://doi.org/10.1175/JCLI-D-19-0076.1 |
genre |
North Pole polar night |
genre_facet |
North Pole polar night |
op_relation |
Journal of Climate--J. Climate--0894-8755--1520-0442 articles:23254 ark:/85065/d7445qp9 doi:10.1175/JCLI-D-19-0076.1 |
op_rights |
Copyright 2020 American Meteorological Society (AMS). |
op_doi |
https://doi.org/10.1175/JCLI-D-19-0076.1 |
container_title |
Journal of Climate |
container_volume |
33 |
container_issue |
8 |
container_start_page |
3093 |
op_container_end_page |
3106 |
_version_ |
1797589314595454976 |