D‐region high‐latitude forcing factors
Abstract The subionospheric very low frequency (VLF) radio wave technique provides the possibility of investigating the response of the ionospheric D‐region to a diversity of transient and long‐term physical phenomena originating from above (e.g., energetic particle precipitation) and from below (e....
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ftunivoulu:oai:oulu.fi:nbnfi-fe2019042613376 2023-07-30T04:06:49+02:00 D‐region high‐latitude forcing factors Macotela, E. L. (Edith L.) Clilverd, M. (Mark) Manninen, J. (Jyrki) Moffat‐Griffin, T. (Tracy) Newnham, D. A. (David A.) Raita, T. (Tero) Rodger, C. J. (Craig J.) 2019 application/pdf http://urn.fi/urn:nbn:fi-fe2019042613376 eng eng American Geophysical Union info:eu-repo/semantics/openAccess © 2019 American Geophysical Union. All Rights Reserved. This is the peer reviewed version of the following article: Macotela, E. L., Clilverd, M., Manninen, J., Moffat‐Griffin, T., Newnham, D. A., Raita, T., & Rodger, C. J. ( 2019). D‐region high‐latitude forcing factors. Journal of Geophysical Research: Space Physics, 124, 765– 781, which has been published in final form at https://doi.org/10.1029/2018JA026049. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2019 ftunivoulu 2023-07-08T19:59:50Z Abstract The subionospheric very low frequency (VLF) radio wave technique provides the possibility of investigating the response of the ionospheric D‐region to a diversity of transient and long‐term physical phenomena originating from above (e.g., energetic particle precipitation) and from below (e.g., atmospheric waves). In this study, we identify the periodicities that appear in VLF measurements and investigate how they may be related to changes in space weather and atmospheric activity. The powerful VLF signal transmitted from NAA (24 kHz) on the east coast of the United States, and received at Sodankylä, Finland, was analyzed. Wavelet transform, wavelet power spectrum, wavelet coherence, and cross‐wavelet spectrum were computed for daily averages of selected ionospheric, space weather, and atmospheric parameters from November 2008 until June 2018. Our results show that the significant VLF periods that appear during solar cycle 24 are the annual oscillation, semiannual oscillation, 121‐day, 86‐day, 61‐day, and solar rotation oscillations. We found that the annual oscillation corresponds to variability in mesospheric temperature and solar Lyman‐α (Ly‐α) flux and the semiannual oscillation to variability in space weather‐related parameters. The solar rotation oscillation observed in the VLF variability is mainly related to the Ly‐α flux variation at solar maximum and to geomagnetic activity variation during the declining phase of the solar cycle. Our results are important since they strengthen our understanding of the Earth’s D‐region response to solar and atmospheric forcing. Article in Journal/Newspaper Sodankylä Jultika - University of Oulu repository Sodankylä ENVELOPE(26.600,26.600,67.417,67.417) |
institution |
Open Polar |
collection |
Jultika - University of Oulu repository |
op_collection_id |
ftunivoulu |
language |
English |
description |
Abstract The subionospheric very low frequency (VLF) radio wave technique provides the possibility of investigating the response of the ionospheric D‐region to a diversity of transient and long‐term physical phenomena originating from above (e.g., energetic particle precipitation) and from below (e.g., atmospheric waves). In this study, we identify the periodicities that appear in VLF measurements and investigate how they may be related to changes in space weather and atmospheric activity. The powerful VLF signal transmitted from NAA (24 kHz) on the east coast of the United States, and received at Sodankylä, Finland, was analyzed. Wavelet transform, wavelet power spectrum, wavelet coherence, and cross‐wavelet spectrum were computed for daily averages of selected ionospheric, space weather, and atmospheric parameters from November 2008 until June 2018. Our results show that the significant VLF periods that appear during solar cycle 24 are the annual oscillation, semiannual oscillation, 121‐day, 86‐day, 61‐day, and solar rotation oscillations. We found that the annual oscillation corresponds to variability in mesospheric temperature and solar Lyman‐α (Ly‐α) flux and the semiannual oscillation to variability in space weather‐related parameters. The solar rotation oscillation observed in the VLF variability is mainly related to the Ly‐α flux variation at solar maximum and to geomagnetic activity variation during the declining phase of the solar cycle. Our results are important since they strengthen our understanding of the Earth’s D‐region response to solar and atmospheric forcing. |
format |
Article in Journal/Newspaper |
author |
Macotela, E. L. (Edith L.) Clilverd, M. (Mark) Manninen, J. (Jyrki) Moffat‐Griffin, T. (Tracy) Newnham, D. A. (David A.) Raita, T. (Tero) Rodger, C. J. (Craig J.) |
spellingShingle |
Macotela, E. L. (Edith L.) Clilverd, M. (Mark) Manninen, J. (Jyrki) Moffat‐Griffin, T. (Tracy) Newnham, D. A. (David A.) Raita, T. (Tero) Rodger, C. J. (Craig J.) D‐region high‐latitude forcing factors |
author_facet |
Macotela, E. L. (Edith L.) Clilverd, M. (Mark) Manninen, J. (Jyrki) Moffat‐Griffin, T. (Tracy) Newnham, D. A. (David A.) Raita, T. (Tero) Rodger, C. J. (Craig J.) |
author_sort |
Macotela, E. L. (Edith L.) |
title |
D‐region high‐latitude forcing factors |
title_short |
D‐region high‐latitude forcing factors |
title_full |
D‐region high‐latitude forcing factors |
title_fullStr |
D‐region high‐latitude forcing factors |
title_full_unstemmed |
D‐region high‐latitude forcing factors |
title_sort |
d‐region high‐latitude forcing factors |
publisher |
American Geophysical Union |
publishDate |
2019 |
url |
http://urn.fi/urn:nbn:fi-fe2019042613376 |
long_lat |
ENVELOPE(26.600,26.600,67.417,67.417) |
geographic |
Sodankylä |
geographic_facet |
Sodankylä |
genre |
Sodankylä |
genre_facet |
Sodankylä |
op_rights |
info:eu-repo/semantics/openAccess © 2019 American Geophysical Union. All Rights Reserved. This is the peer reviewed version of the following article: Macotela, E. L., Clilverd, M., Manninen, J., Moffat‐Griffin, T., Newnham, D. A., Raita, T., & Rodger, C. J. ( 2019). D‐region high‐latitude forcing factors. Journal of Geophysical Research: Space Physics, 124, 765– 781, which has been published in final form at https://doi.org/10.1029/2018JA026049. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. |
_version_ |
1772819744990167040 |