Observations of Polar Mesospheric Summer Echoes Resembling Kilometer-Scale Varicose-Mode Flows
The mesosphere and lower thermosphere (MLT) region represents a captivating yet challenging field of research. Remote sensing techniques, such as radar, have proven invaluable for investigating this domain. The Middle Atmosphere Alomar Radar System (MAARSY), located in Northern Norway (69° N, 16° E)...
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Copernicus Publications
2023
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00068796 2023-10-29T02:38:56+01:00 Observations of Polar Mesospheric Summer Echoes Resembling Kilometer-Scale Varicose-Mode Flows Hartisch, Jennifer Chau, Jorge L. Latteck, Ralph Renkwitz, Toralf Zecha, Marius 2023-09 electronic https://doi.org/10.5194/egusphere-2023-1856 https://noa.gwlb.de/receive/cop_mods_00068796 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00067212/egusphere-2023-1856.pdf https://egusphere.copernicus.org/preprints/2023/egusphere-2023-1856/egusphere-2023-1856.pdf eng eng Copernicus Publications https://doi.org/10.5194/egusphere-2023-1856 https://noa.gwlb.de/receive/cop_mods_00068796 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00067212/egusphere-2023-1856.pdf https://egusphere.copernicus.org/preprints/2023/egusphere-2023-1856/egusphere-2023-1856.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2023 ftnonlinearchiv https://doi.org/10.5194/egusphere-2023-1856 2023-10-01T23:21:41Z The mesosphere and lower thermosphere (MLT) region represents a captivating yet challenging field of research. Remote sensing techniques, such as radar, have proven invaluable for investigating this domain. The Middle Atmosphere Alomar Radar System (MAARSY), located in Northern Norway (69° N, 16° E), uses Polar Mesospheric Summer Echoes (PMSE) as tracers to study MLT dynamics across multiple scales. We recently discovered a spatiotemporally highly localized event showing a varicose mode, which is characterized by extreme vertical velocities (|w| ≥ 3σ) of up to 60 m/s in the vertical drafts. Motivated by this finding, our objective is to identify and quantify similar extreme events or comparable varicose structures, i.e. defined by quasi-simultaneous up- and downdrafts that may have been previously overlooked or filtered. To achieve this, we conducted a thorough manual search through a MAARSY dataset, considering the PMSE months (i.e. May, June, July, August) spanning from 2015 to 2021. This search has revealed that these structures do indeed occur relatively frequently with an occurrence rate of up to 2.5 % per month. Over the seven-year period, we observed and recorded more than 700 varicose-mode events and documented their vertical extent, vertical velocity characteristics, duration as well as their occurrence. Remarkably, these events manifest throughout the entire PMSE season with pronounced occurrence rates in June and July, while the probability of their occurrence decreases towards the beginning and end of the PMSE seasons. Furthermore, their diurnal variability aligns with that of PMSE. On average, the observed events persisted for 20 minutes, while the varicose mode caused an average expansion of the PMSE layer by a factor of 1.5, with a vertical expansion averaging around 8 km. Notably, a careful examination of the vertical velocities associated with these events confirmed that approximately 17 % surpassed the 3σ threshold, highlighting their extreme nature. Article in Journal/Newspaper Northern Norway Niedersächsisches Online-Archiv NOA |
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Niedersächsisches Online-Archiv NOA |
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English |
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article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Hartisch, Jennifer Chau, Jorge L. Latteck, Ralph Renkwitz, Toralf Zecha, Marius Observations of Polar Mesospheric Summer Echoes Resembling Kilometer-Scale Varicose-Mode Flows |
topic_facet |
article Verlagsveröffentlichung |
description |
The mesosphere and lower thermosphere (MLT) region represents a captivating yet challenging field of research. Remote sensing techniques, such as radar, have proven invaluable for investigating this domain. The Middle Atmosphere Alomar Radar System (MAARSY), located in Northern Norway (69° N, 16° E), uses Polar Mesospheric Summer Echoes (PMSE) as tracers to study MLT dynamics across multiple scales. We recently discovered a spatiotemporally highly localized event showing a varicose mode, which is characterized by extreme vertical velocities (|w| ≥ 3σ) of up to 60 m/s in the vertical drafts. Motivated by this finding, our objective is to identify and quantify similar extreme events or comparable varicose structures, i.e. defined by quasi-simultaneous up- and downdrafts that may have been previously overlooked or filtered. To achieve this, we conducted a thorough manual search through a MAARSY dataset, considering the PMSE months (i.e. May, June, July, August) spanning from 2015 to 2021. This search has revealed that these structures do indeed occur relatively frequently with an occurrence rate of up to 2.5 % per month. Over the seven-year period, we observed and recorded more than 700 varicose-mode events and documented their vertical extent, vertical velocity characteristics, duration as well as their occurrence. Remarkably, these events manifest throughout the entire PMSE season with pronounced occurrence rates in June and July, while the probability of their occurrence decreases towards the beginning and end of the PMSE seasons. Furthermore, their diurnal variability aligns with that of PMSE. On average, the observed events persisted for 20 minutes, while the varicose mode caused an average expansion of the PMSE layer by a factor of 1.5, with a vertical expansion averaging around 8 km. Notably, a careful examination of the vertical velocities associated with these events confirmed that approximately 17 % surpassed the 3σ threshold, highlighting their extreme nature. |
format |
Article in Journal/Newspaper |
author |
Hartisch, Jennifer Chau, Jorge L. Latteck, Ralph Renkwitz, Toralf Zecha, Marius |
author_facet |
Hartisch, Jennifer Chau, Jorge L. Latteck, Ralph Renkwitz, Toralf Zecha, Marius |
author_sort |
Hartisch, Jennifer |
title |
Observations of Polar Mesospheric Summer Echoes Resembling Kilometer-Scale Varicose-Mode Flows |
title_short |
Observations of Polar Mesospheric Summer Echoes Resembling Kilometer-Scale Varicose-Mode Flows |
title_full |
Observations of Polar Mesospheric Summer Echoes Resembling Kilometer-Scale Varicose-Mode Flows |
title_fullStr |
Observations of Polar Mesospheric Summer Echoes Resembling Kilometer-Scale Varicose-Mode Flows |
title_full_unstemmed |
Observations of Polar Mesospheric Summer Echoes Resembling Kilometer-Scale Varicose-Mode Flows |
title_sort |
observations of polar mesospheric summer echoes resembling kilometer-scale varicose-mode flows |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/egusphere-2023-1856 https://noa.gwlb.de/receive/cop_mods_00068796 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00067212/egusphere-2023-1856.pdf https://egusphere.copernicus.org/preprints/2023/egusphere-2023-1856/egusphere-2023-1856.pdf |
genre |
Northern Norway |
genre_facet |
Northern Norway |
op_relation |
https://doi.org/10.5194/egusphere-2023-1856 https://noa.gwlb.de/receive/cop_mods_00068796 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00067212/egusphere-2023-1856.pdf https://egusphere.copernicus.org/preprints/2023/egusphere-2023-1856/egusphere-2023-1856.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/egusphere-2023-1856 |
_version_ |
1781065420367724544 |