A slow mode wave as a possible source of Pi 2 and associated particle precipitation: a case study
An intensification of auroral luminosity referred to as an auroral break-up often accompanies the onset of geomagnetic pulsation (Pi 2) at the dip-equator. One such auroral break-up occurred at 2239 UT on 16 June, 1986, being accompanied by weak substorm activity (AE~50 nT) which was recorded in all...
Published in: | Annales Geophysicae |
---|---|
Main Authors: | , , , |
Format: | Text |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://doi.org/10.1007/s00585-999-0674-4 https://angeo.copernicus.org/articles/17/674/1999/ |
id |
ftcopernicus:oai:publications.copernicus.org:angeo34381 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:angeo34381 2023-05-15T13:36:36+02:00 A slow mode wave as a possible source of Pi 2 and associated particle precipitation: a case study Saka, O. Watanabe, O. Okada, K. Baker, D. N. 2018-09-27 application/pdf https://doi.org/10.1007/s00585-999-0674-4 https://angeo.copernicus.org/articles/17/674/1999/ eng eng doi:10.1007/s00585-999-0674-4 https://angeo.copernicus.org/articles/17/674/1999/ eISSN: 1432-0576 Text 2018 ftcopernicus https://doi.org/10.1007/s00585-999-0674-4 2020-07-20T16:28:03Z An intensification of auroral luminosity referred to as an auroral break-up often accompanies the onset of geomagnetic pulsation (Pi 2) at the dip-equator. One such auroral break-up occurred at 2239 UT on 16 June, 1986, being accompanied by weak substorm activity (AE~50 nT) which was recorded in all-sky image of Syowa Station, Antarctica (66.2°S, 71.8°E in geomagnetic coordinates). The associated Pi 2 magnetic pulsation was detected by a fluxgate magnetometer in the afternoon sector at the dip-equator (Huancayo, Peru; 1.44°N, 355.9° in geomagnetic coordinates; 12.1°S, 75.2°W in geographic coordinates; L =1.00). In spite of the large separation of the two stations in longitude and latitude, the auroral break-up and subsequent luminosity modulation were seen to be correlated with the wave form of the ground Pi 2 pulsation. This occurred in such a way that the luminosity maximum was seen to occur at the phase of maximum amplitudes of Pi 2 wave form. We argue that the observed correlation could be interpreted as indicating a Pi 2-modulation of a field-aligned acceleration of the low energy electrons that may occur near the equator of the midnight magnetosphere. Key words. Magnetospheric physics (auroral phenomena; energetic particles · precipitating; MHD waves and instabilities) Text Antarc* Antarctica Copernicus Publications: E-Journals Syowa Station Annales Geophysicae 17 5 674 681 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
An intensification of auroral luminosity referred to as an auroral break-up often accompanies the onset of geomagnetic pulsation (Pi 2) at the dip-equator. One such auroral break-up occurred at 2239 UT on 16 June, 1986, being accompanied by weak substorm activity (AE~50 nT) which was recorded in all-sky image of Syowa Station, Antarctica (66.2°S, 71.8°E in geomagnetic coordinates). The associated Pi 2 magnetic pulsation was detected by a fluxgate magnetometer in the afternoon sector at the dip-equator (Huancayo, Peru; 1.44°N, 355.9° in geomagnetic coordinates; 12.1°S, 75.2°W in geographic coordinates; L =1.00). In spite of the large separation of the two stations in longitude and latitude, the auroral break-up and subsequent luminosity modulation were seen to be correlated with the wave form of the ground Pi 2 pulsation. This occurred in such a way that the luminosity maximum was seen to occur at the phase of maximum amplitudes of Pi 2 wave form. We argue that the observed correlation could be interpreted as indicating a Pi 2-modulation of a field-aligned acceleration of the low energy electrons that may occur near the equator of the midnight magnetosphere. Key words. Magnetospheric physics (auroral phenomena; energetic particles · precipitating; MHD waves and instabilities) |
format |
Text |
author |
Saka, O. Watanabe, O. Okada, K. Baker, D. N. |
spellingShingle |
Saka, O. Watanabe, O. Okada, K. Baker, D. N. A slow mode wave as a possible source of Pi 2 and associated particle precipitation: a case study |
author_facet |
Saka, O. Watanabe, O. Okada, K. Baker, D. N. |
author_sort |
Saka, O. |
title |
A slow mode wave as a possible source of Pi 2 and associated particle precipitation: a case study |
title_short |
A slow mode wave as a possible source of Pi 2 and associated particle precipitation: a case study |
title_full |
A slow mode wave as a possible source of Pi 2 and associated particle precipitation: a case study |
title_fullStr |
A slow mode wave as a possible source of Pi 2 and associated particle precipitation: a case study |
title_full_unstemmed |
A slow mode wave as a possible source of Pi 2 and associated particle precipitation: a case study |
title_sort |
slow mode wave as a possible source of pi 2 and associated particle precipitation: a case study |
publishDate |
2018 |
url |
https://doi.org/10.1007/s00585-999-0674-4 https://angeo.copernicus.org/articles/17/674/1999/ |
geographic |
Syowa Station |
geographic_facet |
Syowa Station |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
eISSN: 1432-0576 |
op_relation |
doi:10.1007/s00585-999-0674-4 https://angeo.copernicus.org/articles/17/674/1999/ |
op_doi |
https://doi.org/10.1007/s00585-999-0674-4 |
container_title |
Annales Geophysicae |
container_volume |
17 |
container_issue |
5 |
container_start_page |
674 |
op_container_end_page |
681 |
_version_ |
1766081643009802240 |