Pc 1 pulsations observed at Cambridge Bay in the cusp region and Fort Smith in the auroral region
In order to understand the generation mechanism of daytime Pc 1 magnetic pulsations with 0.3-0.7Hz in the polar cusp and auroral regions, the authors analyzed the dynamic power spectra of the magnetic pulsations observed by the high sensitive induction magnetometer at Cmabridge Bay (Φ=76.8°⩘=299.6°)...
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Faculty of Science, Tohoku University
1986
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ftnipr:oai:nipr.repo.nii.ac.jp:00001991 2023-05-15T15:48:33+02:00 Pc 1 pulsations observed at Cambridge Bay in the cusp region and Fort Smith in the auroral region Yoshio Kato Yutaka Tonegawa 1986-08 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1991 http://id.nii.ac.jp/1291/00001991/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1991&item_no=1&attribute_id=18&file_no=1 en eng Faculty of Science, Tohoku University Department of Aeronautics and Astronautics, Tokai University National Institute of Polar Research https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1991 http://id.nii.ac.jp/1291/00001991/ AA00733561 Memoirs of National Institute of Polar Research. Special issue, 42, 52-57(1986-08) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1991&item_no=1&attribute_id=18&file_no=1 Departmental Bulletin Paper P(論文) 1986 ftnipr 2022-11-19T19:41:20Z In order to understand the generation mechanism of daytime Pc 1 magnetic pulsations with 0.3-0.7Hz in the polar cusp and auroral regions, the authors analyzed the dynamic power spectra of the magnetic pulsations observed by the high sensitive induction magnetometer at Cmabridge Bay (Φ=76.8°⩘=299.6°) and Fort Smith (67.3°, 300.0°) during the period from 14 to 30 August 1974. It is found that Pc 1 pulsations having a patch-like structure were detected at Cambridge Bay in the cusp region near local noon, but were not observed at Fort Smith in the auroral region. On the other hand, during the period from 1300 to 1500 local time (LT) Pc 1 pulsations showing rising frequency with time appeared at Fort Smith in the sub-cleft region, while Pc 1 pulsations having rather stationary frequency were observed simultaneously at Cambridge Bay in the polar cusp region. After 1500LT, the patch-like Pc 1 pulsations disappeared at Cambridge Bay. From the spectrum analysis, a possible model for mechanism of excitation and propagation of daytime Pc 1 is proposed as follows; Pc 1 pulsations observed in the cusp region are the ion cyclotron wave which is excited near the dayside cusp magnetosheath boundary and propagates along the open field lines in the dayside cusp region. On the other hand, Pc 1 pulsations at Fort Smith in the auroral or sub-cleft region are the ion cyclotron wave, generated in the entry layer where the magnetic field is more intense than that in the magnetosheath. Report Cambridge Bay Memoirs of National Institute of Polar Research Polar Research National Institute of Polar Research Repository, Japan Cambridge Bay ENVELOPE(-105.130,-105.130,69.037,69.037) Fort Smith ENVELOPE(-111.889,-111.889,60.004,60.004) |
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Open Polar |
collection |
National Institute of Polar Research Repository, Japan |
op_collection_id |
ftnipr |
language |
English |
description |
In order to understand the generation mechanism of daytime Pc 1 magnetic pulsations with 0.3-0.7Hz in the polar cusp and auroral regions, the authors analyzed the dynamic power spectra of the magnetic pulsations observed by the high sensitive induction magnetometer at Cmabridge Bay (Φ=76.8°⩘=299.6°) and Fort Smith (67.3°, 300.0°) during the period from 14 to 30 August 1974. It is found that Pc 1 pulsations having a patch-like structure were detected at Cambridge Bay in the cusp region near local noon, but were not observed at Fort Smith in the auroral region. On the other hand, during the period from 1300 to 1500 local time (LT) Pc 1 pulsations showing rising frequency with time appeared at Fort Smith in the sub-cleft region, while Pc 1 pulsations having rather stationary frequency were observed simultaneously at Cambridge Bay in the polar cusp region. After 1500LT, the patch-like Pc 1 pulsations disappeared at Cambridge Bay. From the spectrum analysis, a possible model for mechanism of excitation and propagation of daytime Pc 1 is proposed as follows; Pc 1 pulsations observed in the cusp region are the ion cyclotron wave which is excited near the dayside cusp magnetosheath boundary and propagates along the open field lines in the dayside cusp region. On the other hand, Pc 1 pulsations at Fort Smith in the auroral or sub-cleft region are the ion cyclotron wave, generated in the entry layer where the magnetic field is more intense than that in the magnetosheath. |
format |
Report |
author |
Yoshio Kato Yutaka Tonegawa |
spellingShingle |
Yoshio Kato Yutaka Tonegawa Pc 1 pulsations observed at Cambridge Bay in the cusp region and Fort Smith in the auroral region |
author_facet |
Yoshio Kato Yutaka Tonegawa |
author_sort |
Yoshio Kato |
title |
Pc 1 pulsations observed at Cambridge Bay in the cusp region and Fort Smith in the auroral region |
title_short |
Pc 1 pulsations observed at Cambridge Bay in the cusp region and Fort Smith in the auroral region |
title_full |
Pc 1 pulsations observed at Cambridge Bay in the cusp region and Fort Smith in the auroral region |
title_fullStr |
Pc 1 pulsations observed at Cambridge Bay in the cusp region and Fort Smith in the auroral region |
title_full_unstemmed |
Pc 1 pulsations observed at Cambridge Bay in the cusp region and Fort Smith in the auroral region |
title_sort |
pc 1 pulsations observed at cambridge bay in the cusp region and fort smith in the auroral region |
publisher |
Faculty of Science, Tohoku University |
publishDate |
1986 |
url |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1991 http://id.nii.ac.jp/1291/00001991/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1991&item_no=1&attribute_id=18&file_no=1 |
long_lat |
ENVELOPE(-105.130,-105.130,69.037,69.037) ENVELOPE(-111.889,-111.889,60.004,60.004) |
geographic |
Cambridge Bay Fort Smith |
geographic_facet |
Cambridge Bay Fort Smith |
genre |
Cambridge Bay Memoirs of National Institute of Polar Research Polar Research |
genre_facet |
Cambridge Bay Memoirs of National Institute of Polar Research Polar Research |
op_relation |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1991 http://id.nii.ac.jp/1291/00001991/ AA00733561 Memoirs of National Institute of Polar Research. Special issue, 42, 52-57(1986-08) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1991&item_no=1&attribute_id=18&file_no=1 |
_version_ |
1766383534746894336 |