{"created":"2023-07-27T06:50:18.867346+00:00","id":43047,"links":{},"metadata":{"_buckets":{"deposit":"d62abad7-0a16-45ee-a71a-ffa5a08141e9"},"_deposit":{"created_by":18,"id":"43047","owners":[18],"pid":{"revision_id":0,"type":"depid","value":"43047"},"status":"published"},"_oai":{"id":"oai:kanazawa-u.repo.nii.ac.jp:00043047","sets":["2812:2813:2831"]},"author_link":["69253","69254"],"item_9_biblio_info_8":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2003-03","bibliographicIssueDateType":"Issued"},"bibliographicPageStart":"93p.","bibliographicVolumeNumber":"2001-2002","bibliographic_titles":[{"bibliographic_title":"平成14(2002)年度 科学研究費補助金 基盤研究(C) 研究成果報告書"},{"bibliographic_title":"2002 Fiscal Year Final Research Report","bibliographic_titleLang":"en"}]}]},"item_9_creator_33":{"attribute_name":"著者別表示","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{}],"nameIdentifiers":[{},{}]}]},"item_9_description_21":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"大規模な雷雲-地上間の雷放電に伴い観測される下部電離層(高度85〜105km)中の発光現象「elves」は、雷放電電流から放射されるVLF(数kHz〜数十kHz)帯の大振幅電磁波が下部電離層中で窒素分子を励起することにより発生すると考えられている。本研究では、Full wave計算法を用いてVLF電磁波パルスの下部電離層における伝搬を厳密に計算することで、elvesの発生機構を明らかにすることを目的とする。\n本来Full wave計算法は線形計算であるため、大振幅電磁波パルスによる下部電離層の電子加熱と、それによる電子密度及び衝突周波数の時間変化を扱うことができなかった。本研究では、これら電離層パラメータの時間変化の様子を定量的に評価し、結果として生じる電磁波パルス自身の減衰を近似的にFull wave計算に含める手法を開発した。それにより、高度85〜105kmで数百μsのうちに直径数百kmにわたってリング状に広がっていくelvesの時間空間発展を計算することに成功した。\nまた、1回のFull wave計算に際しては数億回以上の平面波の電離層伝搬計算が必要となるが、各計算が独立しているため並列計算が可能である。従来は40台程度のワークステーションを用いて並列計算を行っていたが、本研究では、高速CPU搭載の10台のPCにより構成される並列計算システムを構築して従来よりも高速に計算を実行することに成功した。様々なパラメータで計算を行った結果、雷放電から放射されたVLF電磁波が地球磁場に沿ってホイスラモード波で伝搬することにより、elvesのリング構造に南北及び東西の非対称性が生じることを明らかにした。また、電磁波パルス(雷放電電流)の強度に対するelvesの発光の様子の違い等を検討した。","subitem_description_type":"Abstract"},{"subitem_description":"We have investigated the generation mechanism of \"elves,\" the expanding optical rings created 85-95 km above lightning flashes. Elves are believed to be generated through the excitation of the first positive band of nitrogen molecule, which is stimulated by the electron heating due to the lightning-generated intense electromagnetic pulses (EMPs) illuminating the lower ionosphere. By using a full-wave analysis, we have computed rigorously the propagation in a magnetized ionosphere of the EMPs radiated by lightning current strokes. When incident into the lower ionosphere, an intense EMP heats the electrons and then enhances the collision frequency there, causing the absorption of the EMP energy. Though the full wave analysis cannot treat such a nonlinear temporal change of ionospheric parameters, we have approximately incorporated this effect into the calculation by modifying the up-going EMP in the ionosphere. Making use of a newly developed parallel-computation system with 10 PCs, we have computed the temporal and spatial evolution of elves. Computed results have shown that an optical ring is created at the altitudes of 85-100 km above the lightning, quickly expanding horizontally over 200 km within < 1 ms, which is consistent with the actual observations of elves. It has also been found that because of the EMP propagation in the whistler mode along the Earth's magnetic field line above 90 km, there appears appreciable north-south and east-west asymmetry in the elves ring structures.","subitem_description_type":"Abstract"}]},"item_9_description_22":{"attribute_name":"内容記述","attribute_value_mlt":[{"subitem_description":"研究課題/領域番号:13640447, 研究期間(年度):2001-2002","subitem_description_type":"Other"},{"subitem_description":"出典：「非線形Full wave計算法による雷上空大気発光現象の解析」研究成果報告書　課題番号13640447\n  (KAKEN：科学研究費助成事業データベース（国立情報学研究所）)\n　　　本文データは著者版報告書より作成","subitem_description_type":"Other"}]},"item_9_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.24517/00049394","subitem_identifier_reg_type":"JaLC"}]},"item_9_publisher_17":{"attribute_name":"公開者","attribute_value_mlt":[{"subitem_publisher":"金沢大学自然科学研究科"}]},"item_9_relation_28":{"attribute_name":"関連URI","attribute_value_mlt":[{"subitem_relation_name":[{"subitem_relation_name_text":"https://kaken.nii.ac.jp/search/?qm=50019775"}],"subitem_relation_type_id":{"subitem_relation_type_id_text":"https://kaken.nii.ac.jp/search/?qm=50019775","subitem_relation_type_select":"URI"}},{"subitem_relation_name":[{"subitem_relation_name_text":"https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640447/"}],"subitem_relation_type_id":{"subitem_relation_type_id_text":"https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640447/","subitem_relation_type_select":"URI"}},{"subitem_relation_name":[{"subitem_relation_name_text":"https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-13640447/136404472002kenkyu_seika_hokoku_gaiyo/"}],"subitem_relation_type_id":{"subitem_relation_type_id_text":"https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-13640447/136404472002kenkyu_seika_hokoku_gaiyo/","subitem_relation_type_select":"URI"}}]},"item_9_version_type_25":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_ab4af688f83e57aa","subitem_version_type":"AM"}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2017-12-21"}],"displaytype":"detail","filename":"TE-PR-NAGANO-I-kaken 2003-93ｐ.pdf","filesize":[{"value":"10.0 MB"}],"format":"application/pdf","licensetype":"license_11","mimetype":"application/pdf","url":{"label":"TE-PR-NAGANO-I-kaken 2003-93ｐ.pdf","url":"https://kanazawa-u.repo.nii.ac.jp/record/43047/files/TE-PR-NAGANO-I-kaken 2003-93ｐ.pdf"},"version_id":"45931b4a-07f2-4974-8979-3cbee15966eb"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"research report","resourceuri":"http://purl.org/coar/resource_type/c_18ws"}]},"item_title":"非線形Full wave計算法による雷上空大気発光現象の解析","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"非線形Full wave計算法による雷上空大気発光現象の解析"},{"subitem_title":"Nonlinear full-wave analysis of atmospheric luminous emissions above lightning discharges","subitem_title_language":"en"}]},"item_type_id":"9","owner":"18","path":["2831"],"pubdate":{"attribute_name":"公開日","attribute_value":"2017-12-21"},"publish_date":"2017-12-21","publish_status":"0","recid":"43047","relation_version_is_last":true,"title":["非線形Full wave計算法による雷上空大気発光現象の解析"],"weko_creator_id":"18","weko_shared_id":-1},"updated":"2023-07-27T14:41:14.504053+00:00"}