Ionospheric disturbances during November 30 - December 1, 1988

Abstract

The following ten papers on the observation and the analysis of the large scale ionospheric disturbance phenomena which appeared over the Japanese sky from November 30 to December 1, 1988 were published. (1) Solar weather related to the disturbance on the earth during the phenomena lasted: In order to examine the source of the geomagnetic storm on November 30, the results of having analyzed solar weather were shown. (2) Features of the ionospheric disturbance observed with the digisonde 256 system and an ordinary ionosonde: The structure of the ionosphere arose in the sky over Kokubunji during the above described period was investigated. (3) The ionospheric disturbance observed with the Japanese oblique ionospheric sounding network: The oblique ionogram observed every 15 min by using the oblique sounding network of the Communication Research laboratory was mentioned. (4) Ionospheric oscillation clarified by HF Doppler measuring technique: The results of having observed the medium scale geomagnetic storm during the above described period by HF Doppler measuring technique were shown. (5) Relation of the disturbance in magnatosphere with the disturbance in ionosphere: It was analytically elucidated that the cause of ionospheric disturbance was due to the electric field intruded from magnetosphere. (6) Important role of eastward electric field for the occurrence of irregularity in medium altitude ionosphere: The scintillation at the time of ionospheric disturbance was investigated in detail, and the role of electric field for the formation of EXB drift instability at medium latitude was elucidated. (7) Observation of ionospheric scintillation with the satellite beacon in VHF 20 GHz region: The characteristics of 12 GHz scintillation in ionosphere were discussed. (8) Behavior of medium latitude F region deduced from 136 MHz scintillation, total electron content and the results of observation with an ionosonde: The state of ionospheric disturbance was investigated from the above results of observation. (9) Temporary and spatial change of 150 and 400 MHz ionospheric scintillation resion based on the results of observation with the NNSS satellite. (10) Abnormal propagation of HF and VHF radio waves.

標記期間に日本上空に出現した極めて大規模な電離層擾乱現象に関して観測および解析した以下の論文10件を掲載した。(1)現象持続中の地球擾乱に関連した太陽気象:11月30日の磁気嵐の源を調べるため、太陽気象を解析した結果を示した。(2)ディジゾンデ256システムおよび通常のイオノゾンデにより観測した電離層擾乱の特徴:標記期間中に国分寺上空に発生した電離層の構造を調べた。(3)日本の斜め電離層音響ネットワークにより観測した電離層の擾乱:通信綜合研究所(CRL)の斜め音響ネットワークを用いて15分毎に観測した斜めイオノグラムについて述べた。(4)HFドップラ測定法により明らかにした電離層の振動:標記期間中の中規模磁気嵐をHFドップラ測定法で観測した結果を示した。(5)磁気圏の擾乱と電離層の擾乱の関係:電離層擾乱の原因が磁気圏から侵入した電界のためであることを解析的に明らかにした。(6)中高度における電離層の不規測性の発生に対する東向きの電界の重要な役割:電離層の擾乱時のシンチレーションを詳細に調べ、中緯度におけるE×Bドリフト不安定性の形成に対する電界の役割を解明した。(7)VHF20GHz領域における衛星ビーコンによる電離層シンチレーションの観測:電離層の12GHzシンチレーションの特性について論じた。(8)136MHzシンチレーション、全電子密度およびイオノゾンデの観測結果から演繹した中緯度F領域の挙動:上記観測結果から電離層の擾乱の様子を調べた。(9)NNSS衛星観測結果に基づく150および400MHz電離層シンチレーション領域の一時的および空間的変化について述べた。(10)HFおよびVHFラジオ波の異常伝搬について述べた。