On the relationship of energetic particle precipitation and mesopause temperature
Abstract. Energetic particle precipitation (EPP) has the potential to change the neutral atmospheric temperature in the mesopause region. However, recent results are inconsistent, leaving the mechanism and the actual effect still unresolved. In this study we have searched for electron precipitation...
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Copernicus Publications under license by EGU – European Geosciences Union GmbH
2021
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Online Access: | http://hdl.handle.net/10852/92392 http://urn.nb.no/URN:NBN:no-94978 https://doi.org/10.5194/angeo-39-795-2021 |
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ftoslouniv:oai:www.duo.uio.no:10852/92392 2023-05-15T16:04:50+02:00 On the relationship of energetic particle precipitation and mesopause temperature Enengl, Florine Partamies, Noora Ivchenko, Nickolay Baddeley, Lisa 2021-09-27T12:49:07Z http://hdl.handle.net/10852/92392 http://urn.nb.no/URN:NBN:no-94978 https://doi.org/10.5194/angeo-39-795-2021 EN eng Copernicus Publications under license by EGU – European Geosciences Union GmbH NFR/287427 http://urn.nb.no/URN:NBN:no-94978 Enengl, Florine Partamies, Noora Ivchenko, Nickolay Baddeley, Lisa . On the relationship of energetic particle precipitation and mesopause temperature. Annales Geophysicae. 2021, 39(5), 795-809 http://hdl.handle.net/10852/92392 1939035 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Annales Geophysicae&rft.volume=39&rft.spage=795&rft.date=2021 Annales Geophysicae 39 5 795 809 https://doi.org/10.5194/angeo-39-795-2021 URN:NBN:no-94978 Fulltext https://www.duo.uio.no/bitstream/handle/10852/92392/1/angeo-39-795-2021.pdf Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ CC-BY 0992-7689 Journal article Tidsskriftartikkel Peer reviewed PublishedVersion 2021 ftoslouniv https://doi.org/10.5194/angeo-39-795-2021 2022-03-16T23:33:54Z Abstract. Energetic particle precipitation (EPP) has the potential to change the neutral atmospheric temperature in the mesopause region. However, recent results are inconsistent, leaving the mechanism and the actual effect still unresolved. In this study we have searched for electron precipitation events and investigated a possible correlation between D-region electron density enhancements and simultaneous neutral temperature changes. The rotational temperature of the excited hydroxyl (OH) molecules is retrieved from the infrared spectrum of the OH airglow. The electron density is monitored by the European Incoherent Scatter Scientific Association (EISCAT) Svalbard Radar. We use all available experiments from the International Polar Year (IPY) in 2007–2008 until February 2019. Particle precipitation events are characterized by rapid increases in electron density by a factor of 4 at an altitude range of 80–95 km, which overlaps with the nominal altitude of the infrared OH airglow layer. The OH airglow measurements and the electron density measurements are co-located. Six of the 10 analysed electron precipitation events are associated with a temperature decrease of 10–20 K. Four events were related to a temperature change of less than 10 K. We interpret the results in terms of the change in the chemical composition in the mesosphere. Due to EPP ionization the population of excited OH at the top of the airglow layer may decrease. As a consequence, the airglow peak height changes and the temperatures are probed at lower altitudes. The observed change in temperature thus depends on the behaviour of the vertical temperature profile within the airglow layer. This is in agreement with conclusions of earlier studies but is, for the first time, constructed from electron precipitation measurements as opposed to proxies. The EPP-related temperature change recovers very fast, typically within less than 60 min. We therefore further conclude that this type of EPP event reaching the mesopause region would only have a significant impact on the longer-term heat balance in the mesosphere if the lifetime of the precipitation was much longer than that of an EPP event (30–60 min) found in this study. Article in Journal/Newspaper EISCAT International Polar Year IPY Svalbard Universitet i Oslo: Digitale utgivelser ved UiO (DUO) Svalbard Annales Geophysicae 39 5 795 809 |
institution |
Open Polar |
collection |
Universitet i Oslo: Digitale utgivelser ved UiO (DUO) |
op_collection_id |
ftoslouniv |
language |
English |
description |
Abstract. Energetic particle precipitation (EPP) has the potential to change the neutral atmospheric temperature in the mesopause region. However, recent results are inconsistent, leaving the mechanism and the actual effect still unresolved. In this study we have searched for electron precipitation events and investigated a possible correlation between D-region electron density enhancements and simultaneous neutral temperature changes. The rotational temperature of the excited hydroxyl (OH) molecules is retrieved from the infrared spectrum of the OH airglow. The electron density is monitored by the European Incoherent Scatter Scientific Association (EISCAT) Svalbard Radar. We use all available experiments from the International Polar Year (IPY) in 2007–2008 until February 2019. Particle precipitation events are characterized by rapid increases in electron density by a factor of 4 at an altitude range of 80–95 km, which overlaps with the nominal altitude of the infrared OH airglow layer. The OH airglow measurements and the electron density measurements are co-located. Six of the 10 analysed electron precipitation events are associated with a temperature decrease of 10–20 K. Four events were related to a temperature change of less than 10 K. We interpret the results in terms of the change in the chemical composition in the mesosphere. Due to EPP ionization the population of excited OH at the top of the airglow layer may decrease. As a consequence, the airglow peak height changes and the temperatures are probed at lower altitudes. The observed change in temperature thus depends on the behaviour of the vertical temperature profile within the airglow layer. This is in agreement with conclusions of earlier studies but is, for the first time, constructed from electron precipitation measurements as opposed to proxies. The EPP-related temperature change recovers very fast, typically within less than 60 min. We therefore further conclude that this type of EPP event reaching the mesopause region would only have a significant impact on the longer-term heat balance in the mesosphere if the lifetime of the precipitation was much longer than that of an EPP event (30–60 min) found in this study. |
format |
Article in Journal/Newspaper |
author |
Enengl, Florine Partamies, Noora Ivchenko, Nickolay Baddeley, Lisa |
spellingShingle |
Enengl, Florine Partamies, Noora Ivchenko, Nickolay Baddeley, Lisa On the relationship of energetic particle precipitation and mesopause temperature |
author_facet |
Enengl, Florine Partamies, Noora Ivchenko, Nickolay Baddeley, Lisa |
author_sort |
Enengl, Florine |
title |
On the relationship of energetic particle precipitation and mesopause temperature |
title_short |
On the relationship of energetic particle precipitation and mesopause temperature |
title_full |
On the relationship of energetic particle precipitation and mesopause temperature |
title_fullStr |
On the relationship of energetic particle precipitation and mesopause temperature |
title_full_unstemmed |
On the relationship of energetic particle precipitation and mesopause temperature |
title_sort |
on the relationship of energetic particle precipitation and mesopause temperature |
publisher |
Copernicus Publications under license by EGU – European Geosciences Union GmbH |
publishDate |
2021 |
url |
http://hdl.handle.net/10852/92392 http://urn.nb.no/URN:NBN:no-94978 https://doi.org/10.5194/angeo-39-795-2021 |
geographic |
Svalbard |
geographic_facet |
Svalbard |
genre |
EISCAT International Polar Year IPY Svalbard |
genre_facet |
EISCAT International Polar Year IPY Svalbard |
op_source |
0992-7689 |
op_relation |
NFR/287427 http://urn.nb.no/URN:NBN:no-94978 Enengl, Florine Partamies, Noora Ivchenko, Nickolay Baddeley, Lisa . On the relationship of energetic particle precipitation and mesopause temperature. Annales Geophysicae. 2021, 39(5), 795-809 http://hdl.handle.net/10852/92392 1939035 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Annales Geophysicae&rft.volume=39&rft.spage=795&rft.date=2021 Annales Geophysicae 39 5 795 809 https://doi.org/10.5194/angeo-39-795-2021 URN:NBN:no-94978 Fulltext https://www.duo.uio.no/bitstream/handle/10852/92392/1/angeo-39-795-2021.pdf |
op_rights |
Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/angeo-39-795-2021 |
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Annales Geophysicae |
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39 |
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5 |
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795 |
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809 |
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1766400468751220736 |