A study of quasi-periodic ELF-VLF emissions at three Antarctic stations: evidence for off-equatorial generation?
The spatial extent and temporal behaviour of quasi-periodic (QP) intensity modulations of 0.5-2 kHz ELF-VLF signals were investigated in a comparative study of data collected at the Antarctic stations of South Pole ( L =14), Halley ( L =4), and Siple ( L =4). Frequently, the waveforms of ELF-VLF sig...
Published in: | Annales Geophysicae |
---|---|
Main Authors: | , , , , , , , |
Format: | Text |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://doi.org/10.1007/s00585-994-0139-8 https://angeo.copernicus.org/articles/12/139/1994/ |
id |
ftcopernicus:oai:publications.copernicus.org:angeo33600 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:angeo33600 2023-05-15T13:31:38+02:00 A study of quasi-periodic ELF-VLF emissions at three Antarctic stations: evidence for off-equatorial generation? Morrison, K. Engebretson, M. J. Beck, J. R. Johnson, J. E. Arnoldy, R. L. Cahill, L. J. Carpenter, D. L. Gallani, M. 2018-09-27 application/pdf https://doi.org/10.1007/s00585-994-0139-8 https://angeo.copernicus.org/articles/12/139/1994/ eng eng doi:10.1007/s00585-994-0139-8 https://angeo.copernicus.org/articles/12/139/1994/ eISSN: 1432-0576 Text 2018 ftcopernicus https://doi.org/10.1007/s00585-994-0139-8 2020-07-20T16:28:18Z The spatial extent and temporal behaviour of quasi-periodic (QP) intensity modulations of 0.5-2 kHz ELF-VLF signals were investigated in a comparative study of data collected at the Antarctic stations of South Pole ( L =14), Halley ( L =4), and Siple ( L =4). Frequently, the waveforms of ELF-VLF signals simultaneously received at each site were identical. Although of similar frequency structure, the waveforms of the accompanying Pc3 magnetic pulsations did not show a one-to-one association. Whereas both are dayside phenomena, QP emissions occur over a smaller range of local times, and have a maximum of occurrence later in the day closer to local noon. QP emissions are identified with the periodic modulation of the electron pitch-angle distribution by the propagation of ULF compressional fast-mode waves through a region. However, contrary to previous ideas, rising-tone emissions do not represent the frequency-time signatures of such waves. In addition to generation close to the equatorial plane, we propose an additional high-latitude source of QP emissions. These emissions are associated with regions of minimum B produced by the dayside compression of the magnetosphere close to the magnetopause. Model magnetic field calculations of these minimum- B regions as a function of magnetic local time and invariant latitude are presented. Text Antarc* Antarctic South pole South pole Copernicus Publications: E-Journals Antarctic Siple ENVELOPE(-83.917,-83.917,-75.917,-75.917) South Pole The Antarctic Annales Geophysicae 12 2/3 139 146 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
The spatial extent and temporal behaviour of quasi-periodic (QP) intensity modulations of 0.5-2 kHz ELF-VLF signals were investigated in a comparative study of data collected at the Antarctic stations of South Pole ( L =14), Halley ( L =4), and Siple ( L =4). Frequently, the waveforms of ELF-VLF signals simultaneously received at each site were identical. Although of similar frequency structure, the waveforms of the accompanying Pc3 magnetic pulsations did not show a one-to-one association. Whereas both are dayside phenomena, QP emissions occur over a smaller range of local times, and have a maximum of occurrence later in the day closer to local noon. QP emissions are identified with the periodic modulation of the electron pitch-angle distribution by the propagation of ULF compressional fast-mode waves through a region. However, contrary to previous ideas, rising-tone emissions do not represent the frequency-time signatures of such waves. In addition to generation close to the equatorial plane, we propose an additional high-latitude source of QP emissions. These emissions are associated with regions of minimum B produced by the dayside compression of the magnetosphere close to the magnetopause. Model magnetic field calculations of these minimum- B regions as a function of magnetic local time and invariant latitude are presented. |
format |
Text |
author |
Morrison, K. Engebretson, M. J. Beck, J. R. Johnson, J. E. Arnoldy, R. L. Cahill, L. J. Carpenter, D. L. Gallani, M. |
spellingShingle |
Morrison, K. Engebretson, M. J. Beck, J. R. Johnson, J. E. Arnoldy, R. L. Cahill, L. J. Carpenter, D. L. Gallani, M. A study of quasi-periodic ELF-VLF emissions at three Antarctic stations: evidence for off-equatorial generation? |
author_facet |
Morrison, K. Engebretson, M. J. Beck, J. R. Johnson, J. E. Arnoldy, R. L. Cahill, L. J. Carpenter, D. L. Gallani, M. |
author_sort |
Morrison, K. |
title |
A study of quasi-periodic ELF-VLF emissions at three Antarctic stations: evidence for off-equatorial generation? |
title_short |
A study of quasi-periodic ELF-VLF emissions at three Antarctic stations: evidence for off-equatorial generation? |
title_full |
A study of quasi-periodic ELF-VLF emissions at three Antarctic stations: evidence for off-equatorial generation? |
title_fullStr |
A study of quasi-periodic ELF-VLF emissions at three Antarctic stations: evidence for off-equatorial generation? |
title_full_unstemmed |
A study of quasi-periodic ELF-VLF emissions at three Antarctic stations: evidence for off-equatorial generation? |
title_sort |
study of quasi-periodic elf-vlf emissions at three antarctic stations: evidence for off-equatorial generation? |
publishDate |
2018 |
url |
https://doi.org/10.1007/s00585-994-0139-8 https://angeo.copernicus.org/articles/12/139/1994/ |
long_lat |
ENVELOPE(-83.917,-83.917,-75.917,-75.917) |
geographic |
Antarctic Siple South Pole The Antarctic |
geographic_facet |
Antarctic Siple South Pole The Antarctic |
genre |
Antarc* Antarctic South pole South pole |
genre_facet |
Antarc* Antarctic South pole South pole |
op_source |
eISSN: 1432-0576 |
op_relation |
doi:10.1007/s00585-994-0139-8 https://angeo.copernicus.org/articles/12/139/1994/ |
op_doi |
https://doi.org/10.1007/s00585-994-0139-8 |
container_title |
Annales Geophysicae |
container_volume |
12 |
container_issue |
2/3 |
container_start_page |
139 |
op_container_end_page |
146 |
_version_ |
1766019611130593280 |