Orographically induced spontaneous imbalance within the jet causing a large-scale gravity wave event
To better understand the impact of gravity waves (GWs) on the middle atmosphere in the current and future climate, it is essential to understand their excitation mechanisms and to quantify their basic properties. Here a new process for GW excitation by orography–jet interaction is discussed. In a ca...
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European Geosciences Union
2021
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Online Access: | https://publikationen.bibliothek.kit.edu/1000135990 https://publikationen.bibliothek.kit.edu/1000135990/122145151 https://doi.org/10.5445/IR/1000135990 |
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ftubkarlsruhe:oai:EVASTAR-Karlsruhe.de:1000135990 2023-05-15T16:28:02+02:00 Orographically induced spontaneous imbalance within the jet causing a large-scale gravity wave event Geldenhuys, Markus Preusse, Peter Krisch, Isabell Zülicke, Christoph Ungermann, Jörn Ern, Manfred Friedl-Vallon, Felix Riese, Martin 2021-07-29 application/pdf https://publikationen.bibliothek.kit.edu/1000135990 https://publikationen.bibliothek.kit.edu/1000135990/122145151 https://doi.org/10.5445/IR/1000135990 eng eng European Geosciences Union info:eu-repo/semantics/altIdentifier/wos/000672721000003 info:eu-repo/semantics/altIdentifier/doi/10.5194/acp-21-10393-2021 info:eu-repo/semantics/altIdentifier/issn/1680-7316 info:eu-repo/semantics/altIdentifier/issn/1680-7324 https://publikationen.bibliothek.kit.edu/1000135990 https://publikationen.bibliothek.kit.edu/1000135990/122145151 https://doi.org/10.5445/IR/1000135990 https://creativecommons.org/licenses/by/4.0/deed.de info:eu-repo/semantics/openAccess CC-BY Atmospheric Chemistry and Physics, 21 (13), 10393-10412 ISSN: 1680-7316, 1680-7324 ddc:550 Earth sciences info:eu-repo/classification/ddc/550 doc-type:article Text info:eu-repo/semantics/article article info:eu-repo/semantics/publishedVersion 2021 ftubkarlsruhe https://doi.org/10.5445/IR/1000135990 https://doi.org/10.5194/acp-21-10393-2021 2023-01-22T23:33:51Z To better understand the impact of gravity waves (GWs) on the middle atmosphere in the current and future climate, it is essential to understand their excitation mechanisms and to quantify their basic properties. Here a new process for GW excitation by orography–jet interaction is discussed. In a case study, we identify the source of a GW observed over Greenland on 10 March 2016 during the POLSTRACC (POLar STRAtosphere in a Changing Climate) aircraft campaign. Measurements were taken with the Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) instrument deployed on the High Altitude Long Range (HALO) German research aircraft. The measured infrared limb radiances are converted into a 3D observational temperature field through the use of inverse modelling and limited-angle tomography. We observe GWs along a transect through Greenland where the GW packet covers ≈ 1/3 of the Greenland mainland. GLORIA observations indicate GWs between 10 and 13 km of altitude with a horizontal wavelength of 330 km, a vertical wavelength of 2 km and a large temperature amplitude of 4.5 K. Slanted phase fronts indicate intrinsic propagation against the wind, while the ground-based propagation is with the wind. The GWs are arrested below a critical layer above the tropospheric jet. Compared to its intrinsic horizontal group velocity (25–72 m s$^{-1}$) the GW packet has a slow vertical group velocity of 0.05–0.2 m s$^{-1}$. This causes the GW packet to propagate long distances while spreading over a large area and remaining constrained to a narrow vertical layer. A plausible source is not only orography, but also out-of-balance winds in a jet exit region and wind shear. To identify the GW source, 3D GLORIA observations are combined with a gravity wave ray tracer, ERA5 reanalysis and high-resolution numerical experiments. In a numerical experiment with a smoothed orography, GW activity is quite weak, indicating that the GWs in the realistic orography experiment are due to orography. However, analysis shows that these ... Article in Journal/Newspaper Greenland KITopen (Karlsruhe Institute of Technologie) Greenland |
institution |
Open Polar |
collection |
KITopen (Karlsruhe Institute of Technologie) |
op_collection_id |
ftubkarlsruhe |
language |
English |
topic |
ddc:550 Earth sciences info:eu-repo/classification/ddc/550 |
spellingShingle |
ddc:550 Earth sciences info:eu-repo/classification/ddc/550 Geldenhuys, Markus Preusse, Peter Krisch, Isabell Zülicke, Christoph Ungermann, Jörn Ern, Manfred Friedl-Vallon, Felix Riese, Martin Orographically induced spontaneous imbalance within the jet causing a large-scale gravity wave event |
topic_facet |
ddc:550 Earth sciences info:eu-repo/classification/ddc/550 |
description |
To better understand the impact of gravity waves (GWs) on the middle atmosphere in the current and future climate, it is essential to understand their excitation mechanisms and to quantify their basic properties. Here a new process for GW excitation by orography–jet interaction is discussed. In a case study, we identify the source of a GW observed over Greenland on 10 March 2016 during the POLSTRACC (POLar STRAtosphere in a Changing Climate) aircraft campaign. Measurements were taken with the Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) instrument deployed on the High Altitude Long Range (HALO) German research aircraft. The measured infrared limb radiances are converted into a 3D observational temperature field through the use of inverse modelling and limited-angle tomography. We observe GWs along a transect through Greenland where the GW packet covers ≈ 1/3 of the Greenland mainland. GLORIA observations indicate GWs between 10 and 13 km of altitude with a horizontal wavelength of 330 km, a vertical wavelength of 2 km and a large temperature amplitude of 4.5 K. Slanted phase fronts indicate intrinsic propagation against the wind, while the ground-based propagation is with the wind. The GWs are arrested below a critical layer above the tropospheric jet. Compared to its intrinsic horizontal group velocity (25–72 m s$^{-1}$) the GW packet has a slow vertical group velocity of 0.05–0.2 m s$^{-1}$. This causes the GW packet to propagate long distances while spreading over a large area and remaining constrained to a narrow vertical layer. A plausible source is not only orography, but also out-of-balance winds in a jet exit region and wind shear. To identify the GW source, 3D GLORIA observations are combined with a gravity wave ray tracer, ERA5 reanalysis and high-resolution numerical experiments. In a numerical experiment with a smoothed orography, GW activity is quite weak, indicating that the GWs in the realistic orography experiment are due to orography. However, analysis shows that these ... |
format |
Article in Journal/Newspaper |
author |
Geldenhuys, Markus Preusse, Peter Krisch, Isabell Zülicke, Christoph Ungermann, Jörn Ern, Manfred Friedl-Vallon, Felix Riese, Martin |
author_facet |
Geldenhuys, Markus Preusse, Peter Krisch, Isabell Zülicke, Christoph Ungermann, Jörn Ern, Manfred Friedl-Vallon, Felix Riese, Martin |
author_sort |
Geldenhuys, Markus |
title |
Orographically induced spontaneous imbalance within the jet causing a large-scale gravity wave event |
title_short |
Orographically induced spontaneous imbalance within the jet causing a large-scale gravity wave event |
title_full |
Orographically induced spontaneous imbalance within the jet causing a large-scale gravity wave event |
title_fullStr |
Orographically induced spontaneous imbalance within the jet causing a large-scale gravity wave event |
title_full_unstemmed |
Orographically induced spontaneous imbalance within the jet causing a large-scale gravity wave event |
title_sort |
orographically induced spontaneous imbalance within the jet causing a large-scale gravity wave event |
publisher |
European Geosciences Union |
publishDate |
2021 |
url |
https://publikationen.bibliothek.kit.edu/1000135990 https://publikationen.bibliothek.kit.edu/1000135990/122145151 https://doi.org/10.5445/IR/1000135990 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Atmospheric Chemistry and Physics, 21 (13), 10393-10412 ISSN: 1680-7316, 1680-7324 |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/000672721000003 info:eu-repo/semantics/altIdentifier/doi/10.5194/acp-21-10393-2021 info:eu-repo/semantics/altIdentifier/issn/1680-7316 info:eu-repo/semantics/altIdentifier/issn/1680-7324 https://publikationen.bibliothek.kit.edu/1000135990 https://publikationen.bibliothek.kit.edu/1000135990/122145151 https://doi.org/10.5445/IR/1000135990 |
op_rights |
https://creativecommons.org/licenses/by/4.0/deed.de info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5445/IR/1000135990 https://doi.org/10.5194/acp-21-10393-2021 |
_version_ |
1766017653717073920 |