Spring‐Fall Asymmetry in VLF Amplitudes Recorded in the North Atlantic Region: The Fall‐Effect
A spring-fall asymmetry is observed in daytime amplitude values of very low frequency (VLF) radio wave signals propagating over the North Atlantic during 2011–2019. We explore the processes behind this asymmetry by comparing against mesospheric mean temperatures and the semidiurnal solar tide (S2) i...
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ftleibnizopen:oai:oai.leibnizopen.de:nlu88IgBdbrxVwz6V67_ 2023-07-16T03:59:44+02:00 Spring‐Fall Asymmetry in VLF Amplitudes Recorded in the North Atlantic Region: The Fall‐Effect Macotela, E.L. Clilverd, M. Renkwitz, T. Chau, J. Manninen, J. Banyś, D. 2021 application/pdf https://oa.tib.eu/renate/handle/123456789/8054 https://doi.org/10.34657/7095 eng eng Hoboken, NJ : Wiley CC BY-NC-ND 4.0 Unported https://creativecommons.org/licenses/by-nc-nd/4.0/ Geophysical research letters : GRL 48 (2021), Nr. 16 D-region mesospheric temperature semidiurnal solar tide VLF propagation VLF signal absorption 550 article Text 2021 ftleibnizopen https://doi.org/10.34657/7095 2023-06-25T23:39:02Z A spring-fall asymmetry is observed in daytime amplitude values of very low frequency (VLF) radio wave signals propagating over the North Atlantic during 2011–2019. We explore the processes behind this asymmetry by comparing against mesospheric mean temperatures and the semidiurnal solar tide (S2) in mesospheric winds. The solar radiation influence on VLF subionospheric propagation was removed from the daytime VLF amplitude values, isolating the fall-effect. Similarly, the symmetric background level was removed from mesospheric mean temperatures undertaking comparable analysis. During fall, all three analyzed parameters experience significant deviation from their background levels. The VLF amplitude variation during spring is explained by the seasonal variation in solar illumination conditions, while the fall-effect can be interpreted as a mean zonal wind reversal associated with both a S2 enhancement, and temperature reductions. Decreases in temperature can produce decreases in collision frequency, reducing VLF signal absorption, driving the observed VLF asymmetry. publishedVersion Article in Journal/Newspaper North Atlantic LeibnizOpen (The Leibniz Association) |
institution |
Open Polar |
collection |
LeibnizOpen (The Leibniz Association) |
op_collection_id |
ftleibnizopen |
language |
English |
topic |
D-region mesospheric temperature semidiurnal solar tide VLF propagation VLF signal absorption 550 |
spellingShingle |
D-region mesospheric temperature semidiurnal solar tide VLF propagation VLF signal absorption 550 Macotela, E.L. Clilverd, M. Renkwitz, T. Chau, J. Manninen, J. Banyś, D. Spring‐Fall Asymmetry in VLF Amplitudes Recorded in the North Atlantic Region: The Fall‐Effect |
topic_facet |
D-region mesospheric temperature semidiurnal solar tide VLF propagation VLF signal absorption 550 |
description |
A spring-fall asymmetry is observed in daytime amplitude values of very low frequency (VLF) radio wave signals propagating over the North Atlantic during 2011–2019. We explore the processes behind this asymmetry by comparing against mesospheric mean temperatures and the semidiurnal solar tide (S2) in mesospheric winds. The solar radiation influence on VLF subionospheric propagation was removed from the daytime VLF amplitude values, isolating the fall-effect. Similarly, the symmetric background level was removed from mesospheric mean temperatures undertaking comparable analysis. During fall, all three analyzed parameters experience significant deviation from their background levels. The VLF amplitude variation during spring is explained by the seasonal variation in solar illumination conditions, while the fall-effect can be interpreted as a mean zonal wind reversal associated with both a S2 enhancement, and temperature reductions. Decreases in temperature can produce decreases in collision frequency, reducing VLF signal absorption, driving the observed VLF asymmetry. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Macotela, E.L. Clilverd, M. Renkwitz, T. Chau, J. Manninen, J. Banyś, D. |
author_facet |
Macotela, E.L. Clilverd, M. Renkwitz, T. Chau, J. Manninen, J. Banyś, D. |
author_sort |
Macotela, E.L. |
title |
Spring‐Fall Asymmetry in VLF Amplitudes Recorded in the North Atlantic Region: The Fall‐Effect |
title_short |
Spring‐Fall Asymmetry in VLF Amplitudes Recorded in the North Atlantic Region: The Fall‐Effect |
title_full |
Spring‐Fall Asymmetry in VLF Amplitudes Recorded in the North Atlantic Region: The Fall‐Effect |
title_fullStr |
Spring‐Fall Asymmetry in VLF Amplitudes Recorded in the North Atlantic Region: The Fall‐Effect |
title_full_unstemmed |
Spring‐Fall Asymmetry in VLF Amplitudes Recorded in the North Atlantic Region: The Fall‐Effect |
title_sort |
spring‐fall asymmetry in vlf amplitudes recorded in the north atlantic region: the fall‐effect |
publisher |
Hoboken, NJ : Wiley |
publishDate |
2021 |
url |
https://oa.tib.eu/renate/handle/123456789/8054 https://doi.org/10.34657/7095 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Geophysical research letters : GRL 48 (2021), Nr. 16 |
op_rights |
CC BY-NC-ND 4.0 Unported https://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_doi |
https://doi.org/10.34657/7095 |
_version_ |
1771547957232926720 |