Long-term determination of energetic electron precipitation into the atmosphere from AARDDVARK subionospheric VLF observations
We analyze observations of subionospherically propagating very low frequency (VLF) radio waves to determine outer radiation belt energetic electron precipitation (EEP) flux magnitudes. The radio wave receiver in Sodankylä, Finland (Sodankylä Geophysical Observatory) observes signals from the transmi...
Published in: | Journal of Geophysical Research: Space Physics |
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ftnerc:oai:nora.nerc.ac.uk:510826 2023-05-15T13:49:32+02:00 Long-term determination of energetic electron precipitation into the atmosphere from AARDDVARK subionospheric VLF observations Neal, Jason J. Rodger, Craig J. Clilverd, Mark A. Thomson, Neil R. Raita, Tero Ulich, Thomas 2015-04-17 text http://nora.nerc.ac.uk/id/eprint/510826/ https://nora.nerc.ac.uk/id/eprint/510826/1/Neal_et_al-2015-Journal_of_Geophysical_Research__Space_Physics.pdf https://doi.org/10.1002/2014JA020689 en eng Wiley https://nora.nerc.ac.uk/id/eprint/510826/1/Neal_et_al-2015-Journal_of_Geophysical_Research__Space_Physics.pdf Neal, Jason J.; Rodger, Craig J.; Clilverd, Mark A. orcid:0000-0002-7388-1529 Thomson, Neil R.; Raita, Tero; Ulich, Thomas. 2015 Long-term determination of energetic electron precipitation into the atmosphere from AARDDVARK subionospheric VLF observations. Journal of Geophysical Research: Space Physics, 120 (3). 2194-2211. https://doi.org/10.1002/2014JA020689 <https://doi.org/10.1002/2014JA020689> Publication - Article PeerReviewed 2015 ftnerc https://doi.org/10.1002/2014JA020689 2023-02-04T19:41:34Z We analyze observations of subionospherically propagating very low frequency (VLF) radio waves to determine outer radiation belt energetic electron precipitation (EEP) flux magnitudes. The radio wave receiver in Sodankylä, Finland (Sodankylä Geophysical Observatory) observes signals from the transmitter with call sign NAA (Cutler, Maine). The receiver is part of the Antarctic-Arctic Radiation-belt Dynamic Deposition VLF Atmospheric Research Konsortia (AARDDVARK). We use a near-continuous data set spanning November 2004 until December 2013 to determine the long time period EEP variations. We determine quiet day curves over the entire period and use these to identify propagation disturbances caused by EEP. Long Wave Propagation Code radio wave propagation modeling is used to estimate the precipitating electron flux magnitudes from the observed amplitude disturbances, allowing for solar cycle changes in the ambient D region and dynamic variations in the EEP energy spectra. Our method performs well during the summer months when the daylit ionosphere is most stable but fails during the winter. From the summer observations, we have obtained 693 days worth of hourly EEP flux magnitudes over the 2004–2013 period. These AARDDVARK-based fluxes agree well with independent satellite precipitation measurements during high-intensity events. However, our method of EEP detection is 10–50 times more sensitive to low flux levels than the satellite measurements. Our EEP variations also show good agreement with the variation in lower band chorus wave powers, providing some confidence that chorus is the primary driver for the outer belt precipitation we are monitoring. Article in Journal/Newspaper Antarc* Antarctic Arctic Sodankylä Natural Environment Research Council: NERC Open Research Archive Arctic Antarctic The Antarctic Sodankylä ENVELOPE(26.600,26.600,67.417,67.417) Cutler ENVELOPE(-60.981,-60.981,-62.612,-62.612) Journal of Geophysical Research: Space Physics 120 3 2194 2211 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
We analyze observations of subionospherically propagating very low frequency (VLF) radio waves to determine outer radiation belt energetic electron precipitation (EEP) flux magnitudes. The radio wave receiver in Sodankylä, Finland (Sodankylä Geophysical Observatory) observes signals from the transmitter with call sign NAA (Cutler, Maine). The receiver is part of the Antarctic-Arctic Radiation-belt Dynamic Deposition VLF Atmospheric Research Konsortia (AARDDVARK). We use a near-continuous data set spanning November 2004 until December 2013 to determine the long time period EEP variations. We determine quiet day curves over the entire period and use these to identify propagation disturbances caused by EEP. Long Wave Propagation Code radio wave propagation modeling is used to estimate the precipitating electron flux magnitudes from the observed amplitude disturbances, allowing for solar cycle changes in the ambient D region and dynamic variations in the EEP energy spectra. Our method performs well during the summer months when the daylit ionosphere is most stable but fails during the winter. From the summer observations, we have obtained 693 days worth of hourly EEP flux magnitudes over the 2004–2013 period. These AARDDVARK-based fluxes agree well with independent satellite precipitation measurements during high-intensity events. However, our method of EEP detection is 10–50 times more sensitive to low flux levels than the satellite measurements. Our EEP variations also show good agreement with the variation in lower band chorus wave powers, providing some confidence that chorus is the primary driver for the outer belt precipitation we are monitoring. |
format |
Article in Journal/Newspaper |
author |
Neal, Jason J. Rodger, Craig J. Clilverd, Mark A. Thomson, Neil R. Raita, Tero Ulich, Thomas |
spellingShingle |
Neal, Jason J. Rodger, Craig J. Clilverd, Mark A. Thomson, Neil R. Raita, Tero Ulich, Thomas Long-term determination of energetic electron precipitation into the atmosphere from AARDDVARK subionospheric VLF observations |
author_facet |
Neal, Jason J. Rodger, Craig J. Clilverd, Mark A. Thomson, Neil R. Raita, Tero Ulich, Thomas |
author_sort |
Neal, Jason J. |
title |
Long-term determination of energetic electron precipitation into the atmosphere from AARDDVARK subionospheric VLF observations |
title_short |
Long-term determination of energetic electron precipitation into the atmosphere from AARDDVARK subionospheric VLF observations |
title_full |
Long-term determination of energetic electron precipitation into the atmosphere from AARDDVARK subionospheric VLF observations |
title_fullStr |
Long-term determination of energetic electron precipitation into the atmosphere from AARDDVARK subionospheric VLF observations |
title_full_unstemmed |
Long-term determination of energetic electron precipitation into the atmosphere from AARDDVARK subionospheric VLF observations |
title_sort |
long-term determination of energetic electron precipitation into the atmosphere from aarddvark subionospheric vlf observations |
publisher |
Wiley |
publishDate |
2015 |
url |
http://nora.nerc.ac.uk/id/eprint/510826/ https://nora.nerc.ac.uk/id/eprint/510826/1/Neal_et_al-2015-Journal_of_Geophysical_Research__Space_Physics.pdf https://doi.org/10.1002/2014JA020689 |
long_lat |
ENVELOPE(26.600,26.600,67.417,67.417) ENVELOPE(-60.981,-60.981,-62.612,-62.612) |
geographic |
Arctic Antarctic The Antarctic Sodankylä Cutler |
geographic_facet |
Arctic Antarctic The Antarctic Sodankylä Cutler |
genre |
Antarc* Antarctic Arctic Sodankylä |
genre_facet |
Antarc* Antarctic Arctic Sodankylä |
op_relation |
https://nora.nerc.ac.uk/id/eprint/510826/1/Neal_et_al-2015-Journal_of_Geophysical_Research__Space_Physics.pdf Neal, Jason J.; Rodger, Craig J.; Clilverd, Mark A. orcid:0000-0002-7388-1529 Thomson, Neil R.; Raita, Tero; Ulich, Thomas. 2015 Long-term determination of energetic electron precipitation into the atmosphere from AARDDVARK subionospheric VLF observations. Journal of Geophysical Research: Space Physics, 120 (3). 2194-2211. https://doi.org/10.1002/2014JA020689 <https://doi.org/10.1002/2014JA020689> |
op_doi |
https://doi.org/10.1002/2014JA020689 |
container_title |
Journal of Geophysical Research: Space Physics |
container_volume |
120 |
container_issue |
3 |
container_start_page |
2194 |
op_container_end_page |
2211 |
_version_ |
1766251491714138112 |