Role of the plasmapause in dictating the ground accessibility of ELF/VLF chorus
This study explores the manner in which the plasmapause is responsible for dictating which magnetospheric source regions of ELF/VLF chorus are able to propagate to and be received by midlatitude stations on the ground. First, we explore the effects of plasmapause extent on ground-based observations...
Published in: | Journal of Geophysical Research: Space Physics |
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Online Access: | https://doi.org/10.1029/2010JA015955 http://libdigitalcollections.ku.edu.tr/cdm/ref/collection/IR/id/676 |
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ftunivkocdc:oai:libdigitalcollections.ku.edu.tr:IR/676 2023-05-15T13:47:06+02:00 Role of the plasmapause in dictating the ground accessibility of ELF/VLF chorus İnan, Umran Savaş Golden, D. I.; Spasojevic, M.; Foust, F. R.; Lehtinen, N. G.; Meredith, N. P. College of Engineering Department of Electrical and Electronics Engineering 2010 pdf https://doi.org/10.1029/2010JA015955 http://libdigitalcollections.ku.edu.tr/cdm/ref/collection/IR/id/676 English eng American Geophysical Union (AGU) International Publisher version Koç University Institutional Repository 177880 2169-9380 2169-9402 Golden, D. I., et al. "Role of the Plasmapause in Dictating the Ground Accessibility of Elf/Vlf Chorus." Journal of Geophysical Research-Space Physics 115 (2010): 15. http://dx.doi.org/10.1029/2010JA015955 IR00611 WoS; Scopus 0538627; N00014-09-1-0034, Z882802 NA http://libdigitalcollections.ku.edu.tr/cdm/ref/collection/IR/id/676 Journal of Geophysical Research: Space Physics Astronomy and astrophysics Whistler-mode chorus Radiation belt electrons Magnetospherically reflected whistlers Relativistic energies Substorm activity Magnetic-field Emissions Frequency Density Acceleration Journal article text/academic publication 2010 ftunivkocdc https://doi.org/10.1029/2010JA015955 2023-02-09T18:04:10Z This study explores the manner in which the plasmapause is responsible for dictating which magnetospheric source regions of ELF/VLF chorus are able to propagate to and be received by midlatitude stations on the ground. First, we explore the effects of plasmapause extent on ground-based observations of chorus via a 3 month study of ground-based measurements of chorus at Palmer Station, Antarctica (L = 2.4, 50 degrees S geomagnetic latitude), and data on the plasmapause extent from the IMAGE EUV instrument. It is found that chorus normalized occurrence peaks when the plasmapause is at L similar to 2.6, somewhat higher than Palmer's L shell, and that this occurrence peak persists across a range of observed chorus frequencies. Next, reverse ray tracing is employed to evaluate the portion of the equatorial chorus source region, distributed in radial distance and wave normal, from which chorus is able to reach Palmer Station via propagation in a nonducted mode. The results of ray tracing are similar to those of observations, with a peak of expected occurrence when the plasmapause is at L similar to 3. The exact location of the peak is frequency dependent. This supports the conclusion that the ability of chorus to propagate to low altitudes and the ground is a strong function of instantaneous plasmapause extent and that peak occurrence of chorus at a given ground station may occur when the L shell of the plasmapause is somewhat beyond that of the observing station. These results also suggest that chorus observed on the ground at midlatitude stations propagates predominantly in the nonducted mode. National Science Foundation; Office of Naval Research Article in Journal/Newspaper Antarc* Antarctica Koç University Suna Kıraç Library’ Digital Collections Palmer Station ENVELOPE(-64.050,-64.050,-64.770,-64.770) Palmer-Station ENVELOPE(-64.050,-64.050,-64.770,-64.770) Journal of Geophysical Research: Space Physics 115 A11 n/a n/a |
institution |
Open Polar |
collection |
Koç University Suna Kıraç Library’ Digital Collections |
op_collection_id |
ftunivkocdc |
language |
English |
topic |
Astronomy and astrophysics Whistler-mode chorus Radiation belt electrons Magnetospherically reflected whistlers Relativistic energies Substorm activity Magnetic-field Emissions Frequency Density Acceleration |
spellingShingle |
Astronomy and astrophysics Whistler-mode chorus Radiation belt electrons Magnetospherically reflected whistlers Relativistic energies Substorm activity Magnetic-field Emissions Frequency Density Acceleration Role of the plasmapause in dictating the ground accessibility of ELF/VLF chorus |
topic_facet |
Astronomy and astrophysics Whistler-mode chorus Radiation belt electrons Magnetospherically reflected whistlers Relativistic energies Substorm activity Magnetic-field Emissions Frequency Density Acceleration |
description |
This study explores the manner in which the plasmapause is responsible for dictating which magnetospheric source regions of ELF/VLF chorus are able to propagate to and be received by midlatitude stations on the ground. First, we explore the effects of plasmapause extent on ground-based observations of chorus via a 3 month study of ground-based measurements of chorus at Palmer Station, Antarctica (L = 2.4, 50 degrees S geomagnetic latitude), and data on the plasmapause extent from the IMAGE EUV instrument. It is found that chorus normalized occurrence peaks when the plasmapause is at L similar to 2.6, somewhat higher than Palmer's L shell, and that this occurrence peak persists across a range of observed chorus frequencies. Next, reverse ray tracing is employed to evaluate the portion of the equatorial chorus source region, distributed in radial distance and wave normal, from which chorus is able to reach Palmer Station via propagation in a nonducted mode. The results of ray tracing are similar to those of observations, with a peak of expected occurrence when the plasmapause is at L similar to 3. The exact location of the peak is frequency dependent. This supports the conclusion that the ability of chorus to propagate to low altitudes and the ground is a strong function of instantaneous plasmapause extent and that peak occurrence of chorus at a given ground station may occur when the L shell of the plasmapause is somewhat beyond that of the observing station. These results also suggest that chorus observed on the ground at midlatitude stations propagates predominantly in the nonducted mode. National Science Foundation; Office of Naval Research |
author2 |
İnan, Umran Savaş Golden, D. I.; Spasojevic, M.; Foust, F. R.; Lehtinen, N. G.; Meredith, N. P. College of Engineering Department of Electrical and Electronics Engineering |
format |
Article in Journal/Newspaper |
title |
Role of the plasmapause in dictating the ground accessibility of ELF/VLF chorus |
title_short |
Role of the plasmapause in dictating the ground accessibility of ELF/VLF chorus |
title_full |
Role of the plasmapause in dictating the ground accessibility of ELF/VLF chorus |
title_fullStr |
Role of the plasmapause in dictating the ground accessibility of ELF/VLF chorus |
title_full_unstemmed |
Role of the plasmapause in dictating the ground accessibility of ELF/VLF chorus |
title_sort |
role of the plasmapause in dictating the ground accessibility of elf/vlf chorus |
publisher |
American Geophysical Union (AGU) |
publishDate |
2010 |
url |
https://doi.org/10.1029/2010JA015955 http://libdigitalcollections.ku.edu.tr/cdm/ref/collection/IR/id/676 |
long_lat |
ENVELOPE(-64.050,-64.050,-64.770,-64.770) ENVELOPE(-64.050,-64.050,-64.770,-64.770) |
geographic |
Palmer Station Palmer-Station |
geographic_facet |
Palmer Station Palmer-Station |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Journal of Geophysical Research: Space Physics |
op_relation |
Publisher version Koç University Institutional Repository 177880 2169-9380 2169-9402 Golden, D. I., et al. "Role of the Plasmapause in Dictating the Ground Accessibility of Elf/Vlf Chorus." Journal of Geophysical Research-Space Physics 115 (2010): 15. http://dx.doi.org/10.1029/2010JA015955 IR00611 WoS; Scopus 0538627; N00014-09-1-0034, Z882802 NA http://libdigitalcollections.ku.edu.tr/cdm/ref/collection/IR/id/676 |
op_doi |
https://doi.org/10.1029/2010JA015955 |
container_title |
Journal of Geophysical Research: Space Physics |
container_volume |
115 |
container_issue |
A11 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1766246362766114816 |