Observation of ionospheric Alfven resonance at a middle latitude station
This paper intends to report on the statistical results on the spectral resonance structures of the ionospheric Alfven resonances (IAR) in the ULF frequency range 0.1-5.0 Hz on the basis of the analysis of long-term data obtained from July 2000 to December 2002 (2.5 years) at the Karimshino station...
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University of Electro-Communications
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ftnipr:oai:nipr.repo.nii.ac.jp:00006381 2023-05-15T16:59:27+02:00 Observation of ionospheric Alfven resonance at a middle latitude station Masashi Hayakawa Oleg A. Molchanov Alexander Yu. Schekotov Evgeny Fedorov 2004-08 https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=6381 http://id.nii.ac.jp/1291/00006381/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=6381&item_no=1&attribute_id=18&file_no=1 en eng University of Electro-Communications Institute of Physics of the Earth, Russian Academy of Science https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=6381 http://id.nii.ac.jp/1291/00006381/ AA11397422 Advances in polar upper atmosphere research, 18, 65-76(2004-08) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=6381&item_no=1&attribute_id=18&file_no=1 ionospheric Alfven resonator (IAR) ionosphere magnetosphere polarization Departmental Bulletin Paper P(論文) 2004 ftnipr 2022-11-12T19:46:50Z This paper intends to report on the statistical results on the spectral resonance structures of the ionospheric Alfven resonances (IAR) in the ULF frequency range 0.1-5.0 Hz on the basis of the analysis of long-term data obtained from July 2000 to December 2002 (2.5 years) at the Karimshino station (Kamchatka, Russia) (L=2.1) by the conventional 3-component search-coil magnetometer. We analyze both the dynamic spectra of three components and polarization spectra in order to distinguish IAR from other possible noises. The average frequency difference _F between the adjacent maxima, intensity and occurrence rate of the IAR spectra have been estimated from the averaged spectra. Early papers at middle latitudes have been based on a small data base. Based on our first long-term observation at middle latitude, new findings, especially related to the seasonal variation, have emerged from this analysis. (1) There is an evident seasonal variation in the occurrence rate with a maximum in the September-January period and an almost complete absence of IAR structures in the spring-early summer time. (2) Occurrence maximum in the diurnal variation is found at 21-23 LT in the autumn and winter. Almost all the IAR structures are observed at local nighttime. (3) The averaged _F is found to be about 0.2-0.5 Hz in the autumn period but it seems to increase up to 0.5-0.7 Hz in winter. (4) The IAR occurrence rate is inversely correlated with the Kp index of global magnetic activity. (5) The intensity of D component exceeds essentially that of H component of the IAR structures in a majority of cases. Diurnal variations of resonance frequencies in the H and D components are not always identical. Finally the mechanisms to explain the observed characteristics of the IAR have been discussed. Report Kamchatka Advances in polar upper atmosphere research National Institute of Polar Research Repository, Japan |
institution |
Open Polar |
collection |
National Institute of Polar Research Repository, Japan |
op_collection_id |
ftnipr |
language |
English |
topic |
ionospheric Alfven resonator (IAR) ionosphere magnetosphere polarization |
spellingShingle |
ionospheric Alfven resonator (IAR) ionosphere magnetosphere polarization Masashi Hayakawa Oleg A. Molchanov Alexander Yu. Schekotov Evgeny Fedorov Observation of ionospheric Alfven resonance at a middle latitude station |
topic_facet |
ionospheric Alfven resonator (IAR) ionosphere magnetosphere polarization |
description |
This paper intends to report on the statistical results on the spectral resonance structures of the ionospheric Alfven resonances (IAR) in the ULF frequency range 0.1-5.0 Hz on the basis of the analysis of long-term data obtained from July 2000 to December 2002 (2.5 years) at the Karimshino station (Kamchatka, Russia) (L=2.1) by the conventional 3-component search-coil magnetometer. We analyze both the dynamic spectra of three components and polarization spectra in order to distinguish IAR from other possible noises. The average frequency difference _F between the adjacent maxima, intensity and occurrence rate of the IAR spectra have been estimated from the averaged spectra. Early papers at middle latitudes have been based on a small data base. Based on our first long-term observation at middle latitude, new findings, especially related to the seasonal variation, have emerged from this analysis. (1) There is an evident seasonal variation in the occurrence rate with a maximum in the September-January period and an almost complete absence of IAR structures in the spring-early summer time. (2) Occurrence maximum in the diurnal variation is found at 21-23 LT in the autumn and winter. Almost all the IAR structures are observed at local nighttime. (3) The averaged _F is found to be about 0.2-0.5 Hz in the autumn period but it seems to increase up to 0.5-0.7 Hz in winter. (4) The IAR occurrence rate is inversely correlated with the Kp index of global magnetic activity. (5) The intensity of D component exceeds essentially that of H component of the IAR structures in a majority of cases. Diurnal variations of resonance frequencies in the H and D components are not always identical. Finally the mechanisms to explain the observed characteristics of the IAR have been discussed. |
format |
Report |
author |
Masashi Hayakawa Oleg A. Molchanov Alexander Yu. Schekotov Evgeny Fedorov |
author_facet |
Masashi Hayakawa Oleg A. Molchanov Alexander Yu. Schekotov Evgeny Fedorov |
author_sort |
Masashi Hayakawa |
title |
Observation of ionospheric Alfven resonance at a middle latitude station |
title_short |
Observation of ionospheric Alfven resonance at a middle latitude station |
title_full |
Observation of ionospheric Alfven resonance at a middle latitude station |
title_fullStr |
Observation of ionospheric Alfven resonance at a middle latitude station |
title_full_unstemmed |
Observation of ionospheric Alfven resonance at a middle latitude station |
title_sort |
observation of ionospheric alfven resonance at a middle latitude station |
publisher |
University of Electro-Communications |
publishDate |
2004 |
url |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=6381 http://id.nii.ac.jp/1291/00006381/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=6381&item_no=1&attribute_id=18&file_no=1 |
genre |
Kamchatka Advances in polar upper atmosphere research |
genre_facet |
Kamchatka Advances in polar upper atmosphere research |
op_relation |
https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=6381 http://id.nii.ac.jp/1291/00006381/ AA11397422 Advances in polar upper atmosphere research, 18, 65-76(2004-08) https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=6381&item_no=1&attribute_id=18&file_no=1 |
_version_ |
1766051711935315968 |