研究者詳細 - 新堀　淳樹

Response of ionospheric electric fields at mid-low latitudes during sudden commencements 査読有り

Takahashi, N; Kasaba, Y; Shinbori, A; Nishimura, Y; Kikuchi, T; Ebihara, Y; Nagatsuma, T

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 120 巻 ( 6 ) 頁： 4849 - 4862 2015年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Geophysical Research: Space Physics

Using in situ observations from the Republic of China Satellite-1 spacecraft, we investigated the time response and local time dependence of the ionospheric electric field at mid-low latitudes associated with geomagnetic sudden commencements (SCs) that occurred from 1999 to 2004. We found that the ionospheric electric field variation associated with SCs instantaneously responds to the preliminary impulse (PI) signature on the ground regardless of spacecraft local time. Our statistical analysis also supports the global instant transmission of electric field from the polar region. In contrast, the peak time detected in the ionospheric electric field is earlier than that of the equatorial geomagnetic field (~20s before in the PI phase). Based on the ground-ionosphere waveguide model, this time lag can be attributed to the latitudinal difference of ionospheric conductivity. However, the local time distribution of the initial excursion of ionospheric electric field shows that dusk-to-dawn ionospheric electric fields develop during the PI phase. Moreover, the westward electric field in the ionosphere, which produces the preliminary reverse impulse of the geomagnetic field on the dayside feature, appears at 18-22h LT where the ionospheric conductivity beyond the duskside terminator (18h LT) is lower than on the dayside. The result of a magnetohydrodynamic simulation for an ideal SC shows that the electric potential distribution is asymmetric with respect to the noon-midnight meridian. This produces the local time distribution of ionospheric electric fields similar to the observed result, which can be explained by the divergence of the Hall current under nonuniform ionospheric conductivity. Key Points Ionospheric electric fields respond instantaneously and globally Instant transmission of electric field is explained by the waveguide model Nonuniform ionospheric conductivity affects LT dependence of electric field

DOI： 10.1002/2015JA021309

The capacity-building and science-enabling activities of the IUGONET for the solar-terrestrial research community 査読有り

Yatagai, A; Sato, Y; Shinbori, A; Abe, S; UeNo, S

EARTH PLANETS AND SPACE 67 巻 ( 1 ) 2015年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Earth, Planets and Space

Background: This paper presents an overview of the capacity-building activities and science-enabling services of the Inter-university Upper atmosphere Global Observation NETwork (IUGONET) project. This Japanese program, which started in 2009, is building a metadata database (MDDB) of ground-based observations and is developing an analysis software to handle the data linked to the MDDB system for use by the solar-terrestrial physics community. Because the institutional members of the IUGONET are mainly universities in Japan, we explore tools that can contribute to advanced education as well as promote research activities. Findings: In this paper, we describe the utilities of the IUGONET for education, including our capacity-building activities in developing countries. We have regularly facilitated training seminars for Japanese students on the use of our tools (IUGONET MDDB and the software), and we have held capacity-building seminars for young scientists in developing countries. In addition to the MDDB, we have prepared various 'gateway' tools for users who are unfamiliar with 'keywords' to search for data. One of these is a geographical display tool that uses Google Earth (KML file), which is included as supplemental material to this paper. The usefulness of the IUGONET has been proven over its first 5 years of operation by the increasing number of its users, which has led to the production of approximately 500 scientific papers, including 42 thesis papers. Conclusions: The IUGONET community collaborates with the Scientific Committee on Solar-Terrestrial Physics program, not only in its scientific activities, but also in the establishment of E-infrastructure and capacity building.

DOI： 10.1186/s40623-014-0170-2

Thermal and low-energy ion outflows in and through the polar cap: The polar wind and the low-energy component of the cleft ion fountain 査読有り

AGU Geophysical Monograph 2015年

Long-term variation in the upper atmosphere as seen in the geomagnetic solar quiet daily variation 査読有り

Shinbori, A; Koyama, Y; Nose, M; Hori, T; Otsuka, Y; Yatagai, A

EARTH PLANETS AND SPACE 66 巻 ( 1 ) 頁： 1 - 20 2014年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Earth, Planets and Space

Characteristics of long-term variation in the amplitude of solar quiet (Sq) geomagnetic field daily variation have been investigated using 1-h geomagnetic field data obtained from 69 geomagnetic observation stations within the period of 1947 to 2013. The Sq amplitude observed at these geomagnetic stations showed a clear dependence on the 10- to 12-year solar activity cycle and tended to be enhanced during each solar maximum phase. The Sq amplitude was the smallest around the minimum of solar cycle 23/24 in 2008 to 2009. The relationship between the solar F10.7 index and Sq amplitude was approximately linear but about 53% of geomagnetic stations showed a weak nonlinear relation to the solar F10.7 index. In order to remove the effect of solar activity seen in the long-term variation of the Sq amplitude, we calculated a linear or second-order fitting curve between the solar F10.7 index and Sq amplitude during 1947 to 2013 and examined the residual Sq amplitude, which is defined as the deviation from the fitting curve. As a result, the majority of trends in the residual Sq amplitude that passed through a trend test showed negative values over a wide region. This tendency was relatively strong in Europe, India, the eastern part of Canada, and New Zealand. The relationship between the magnetic field intensity at 100-km altitude and residual Sq amplitude showed an anti-correlation for about 71% of the geomagnetic stations. Furthermore, the residual Sq amplitude at the equatorial station (Addis Ababa) was anti-correlated with the absolute value of the magnetic field inclination. This implies movement of the equatorial electrojet due to the secular variation of the ambient magnetic field.

DOI： 10.1186/s40623-014-0155-1

An Interactive Data Language software package to calculate ionospheric conductivity by using numerical models 査読有り

Koyamaa, Y; Shinbori, A; Tanaka, Y; Hori, T; Nosé, M; Oimatsu, S

COMPUTER PHYSICS COMMUNICATIONS 185 巻 ( 12 ) 頁： 3398 - 3405 2014年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Computer Physics Communications

The Inter-university Upper atmosphere Global Observation NETwork (IUGONET) project focuses on handling ground-based observational data of the upper atmosphere. To this end, the project members have been developing a data analysis software package which is based on Interactive Data Language (IDL). Filling the spatial gaps in observational data requires the use of numerical models. In this paper,wediscuss an IDL software package for global ionospheric conductivity by integration of 3rd party numerical models. The model can be used to create further derived models.

DOI： 10.1016/j.cpc.2014.08.011

Long-term variation in the upper atmosphere as seen in the geomagnetic solar quiet daily variation 査読有り

Shinbori, A, Y. Koyama, M, Nose, T. Hori, Y. Otsuka, A. Yatagai

Earth, Planets and Space 65 巻 ( 155 ) 2014年12月

The capacity-building and science-enabling activities of the IUGONET to the solar-terrestrial research community 査読有り

Yatagai, A, Y. Sato, A. Shinbori, S. Abe, S. UeNo, IUGONET Team

Earth, Planets and Space 2014年12月

Interuniversity Upper Atmosphere Global Observation NETwork (IUGONET) meta-database and analysis software 査読有り

Yatagai A., Tanaka Y., Abe S., Shinbori A., Yagi M., UeNo S., Koyama Y., Umemura N., Nosé M., Hori T., Sato Y., Hashiguchi N.O., Kaneda N.

Data Science Journal 13 巻 ( 0 ) 頁： PDA37 - PDA43 2014年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Data Science Journal

An overview of the Interuniversity Upper atmosphere Global Observation NETwork (IUGONET) project is presented. This Japanese program is building a meta-database for ground-based observations of the upper atmosphere, in which metadata connected with various atmospheric radars and photometers, including those located in both polar regions, are archived. By querying the metadata database, researchers are able to access data file/information held by data facilities. Moreover, by utilizing our analysis software, users can download, visualize, and analyze upper-atmospheric data archived in or linked with the system. As a future development, we are looking to make our database interoperable with others.

DOI： 10.2481/dsj.IFPDA-07

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Progress of the IUGONET system - metadata database for upper atmosphere ground-based observation data 査読有り

Abe, S; Umemura, N; Koyama, Y; Tanaka, Y; Yagi, M; Yatagai, A; Shinbori, A; UeNo, S; Sato, Y; Kaneda, N

EARTH PLANETS AND SPACE 66 巻 ( 133 ) 2014年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Earth, Planets and Space

Background: The Interuniversity Upper atmosphere Global Observation NETwork (IUGONET) project is a 6-year research project which started in 2009. The objective of this project is to establish a metadata database of various ground-based observation data covering a wide region from the Sun to the Earth; this will encourage more studies on the mechanisms of long-term variations in the upper atmosphere. Findings: For archiving purposes, the metadata database system for cross-searching various data distributed across many universities and institute was developed based on the existing repository software called DSpace as the core component and the Space Physics Archive Search and Extract (SPASE) data model as the metadata format. The IUGONET metadata database is still in operation since it was released in March 2012. The system is continuously examined, tested, and updated to improve its quality. The OpenSearch interface in the IUGONET metadata database allows the user to use external applications easily for exchanging metadata and/or for analyzing data. Conclusions: We conducted self-examination of our product, which was added for planning future directions of the IUGONET project.

DOI： 10.1186/1880-5981-66-133

超高層物理学分野のメタデータ・データベースへの連想検索の適用(宇宙科学情報解析論文誌第三号) 査読有り

小山幸伸, 阿部修司, 八木学, 梅村宜生, 堀智昭, 新堀淳樹, 佐藤由佳, 家森俊彦, 田中良昌, 橋口典子, 上野悟, 谷田貝亜紀代

宇宙航空研究開発機構研究開発報告 13 巻頁： 89 - 97 2014年3月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宇宙航空研究開発機構

超高層大気に於ける地球規模の物理現象の機構を解明する為には,様々なデータを用いた分野横断的な研究推進が重要である.インターネット上の様々なデータを直ちに取得する為の基盤が,分野横断的な研究の1つの鍵となる.IUGONETプロジェクトは,複数の研究機関によって分散管理されている,様々なデータの URL等の所在情報等を提供可能なメタデータ・データベースを構築することによって,この課題に対処した.しかしながら,このメタデータ・データベースは広範な研究領域を対象としている為,専門分野外のユーザーにとって単語検索時における適切な検索語句の選択が容易でないことが指摘された.これを補助するべく,検索語句の関連語の取得とそれらを用いた再検索クエリ文字列の自動生成を行う為に,そのメタデータ・データベースと連想検索エンジン GETAssocを連携させた.そして,この連想検索用の辞書を作成する為に, SAO/NASA Astrophysics Data Systemからメタデータを抽出した.再クエリ文字列を生成する為に用意した辞書を用いることで,期待通りの連想検索結果を得ることが出来た.

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Analysis software for upper atmospheric data developed by the IUGONET project and its application to polar science 査読有り

Tanaka, Y.-M, A. Shinbori, T. Hori, Y. Koyama, S. Abe, N. Umemura, Y. Sato, M. Yagi, S. UeNo, A. Yatagai, Y. Ogawa, Y. Miyoshi

Advances in Polar Science, 24, 231-240, doi:10.3724/SP.J.1085.2013.00231 2013年12月

Global distributions of storm-time ionospheric currents as seen in geomagnetic field variations 査読有り

Shinbori, A, T. Hori, Y. Tanaka, Y. Koyama, T. Kikuchi, T. Nagatsuma

Advances in Polar Science, 24, 296-314, doi:10.3724/SP.J.1085.2013.00296 24 巻頁： 296 - 314 2013年12月

Inter-university upper atmosphere global observation network (IUGONET) 査読有り

Hayashi H., Koyama Y., Hori T., Tanaka Y., Abe S., Shinbori A., Kagitani M., Kouno T., Yoshida D., UeNo S., Kaneda N., Yoneda M., Umemura N., Tadokoro H., Motoba T.

Data Science Journal 12 巻 2013年4月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Data Science Journal

An overview of the Inter-university Upper atmosphere Global Observation NETwork (IUGONET) project is presented with a brief description of the products to be developed. This is a Japanese inter-university research program to build the metadata database for ground-based observations of the upper atmosphere. The project also develops the software to analyze the observational data provided by various universities/institutes. These products will be of great help to researchers in efficiently finding, obtaining, and utilizing various data dispersed across the universities/institutes. This is expected to contribute significantly to the promotion of interdisciplinary research, leading to more a comprehensive understanding of the upper atmosphere.

DOI： 10.2481/dsj.WDS-030

Inter-university upper atmosphere global observation network (IUGONET) 査読有り

H. Hayashi, Y. Koyama, T. Hori, Y. Tanaka, S. Abe, A. Shinbori, M. Kagitani, T. Kouno, D. Yoshida, S. UeNo, N. Kaneda, M. Yoneda, N. Umemura, H. Tadokoro, T. Motoba

Data Science Journal 12 巻頁： WDS179 - WDS184 2013年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Ubiquity Press Ltd

DOI： 10.2481/dsj.WDS-030

ＩＵＧＯＮＥＴメタデータ登録・管理システムの処理性能評価査読有り

堀智昭, 梅村宜生, 阿部修司, 小山幸伸, 田中良昌, 林寛生, 林寛生, 上野悟, 新堀淳樹, 佐藤由佳, 八木学

宇宙航空研究開発機構研究開発報告 JAXA-RR- ( 12-006 ) 頁： 71 - 78 2013年3月

IUGONETメタデータ登録・管理システムの処理性能評価(宇宙科学情報解析論文誌第二号) 査読有り

堀智昭, 梅村宜生, 阿部修司, 小山幸伸, 田中良昌, 林寛生, 上野悟, 新堀淳樹, 佐藤由佳, 八木学

宇宙航空研究開発機構研究開発報告 12 巻頁： 71 - 78 2013年3月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宇宙航空研究開発機構

本論文では,大学間連携プロジェクト「超高層大気長期変動の全球地上ネットワーク観測・研究」IUGONET)において、作成されたメタデータの受付やメタデータ・データベースへの登録を行っている「メタデータ登録・管理システム」のメタデータ登録処理に関する性能試験の結果について報告する.メタデータ登録・管理システムは,フリーのバージョン管理ソフトウェアであるGit を利用したメタデータ受付部と,そこからメタデータ・データベースへメタデータを登録するメタデータインポート部の,2つの処理部で構成される.この2つの処理部の性能を評価するために,実際に作成・登録されたメタデータを用いて,物理マシンおよび仮想マシン上に構築した Linux環境のそれぞれについて,メタデータの処理速度を計測した.その結果,Gitによるメタデータ受付部は物理マシンか仮想マシンかに依らず,メタデータ総数が500万件レベルまで増えても数分以内で処理が完了するのに対して,メタデータインポート部は処理時間が数時間から数十時間とかなり長くなり,特に検索エンジンであるLuceneのインデックス更新については,物理マシンにおける実行速度が仮想マシンのそれより約 4倍高速であることがわかった.メタデータインポート部を物理マシン上に実装した場合,メタデータ総数 500万件では,新規登録メタデータ数10万件につき5時間弱プラスLuceneインデックス更新で21時間ほど処理時間がかかると見積もられる.

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IUGONET解析ソフトウェアの現状と今後の発展査読有り

田中良昌, 新堀淳樹, 梅村宜生, 堀智昭, 阿部修司, 小山幸伸, 林寛生, 上野悟, 佐藤由佳, 谷田貝亜紀代, 小川泰信, 三好由純, 関華奈子, 宮下幸長, 瀬川朋紀

宇宙航空研究開発機構研究開発報告 12 巻頁： 63 - 70 2013年3月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宇宙航空研究開発機構

大学間連携プロジェクト「超高層大気長期変動の全球地上ネットワーク観測・研究」(IUGONET)では,IUGONET参加機関である東北大学,名古屋大学,京都大学,九州大学および国立極地研究所の5 機関が所有する多種多様な超高層大気データを可視化・解析できるデータ解析ソフトウェアUDAS(iUgonet Data Analysis Software)を開発している.UDAS は,IDL 言語で書かれたTHEMIS ミッションのデータ解析ソフトウェアTDAS(THEMIS Data Analysis Software suite)のプラグインソフトであり,TDAS が持つ様々な時系列データの可視化・解析ツールやGUI 機能を利用することができる.我々は,2011 年5 月よりIUGONET ウェブベージにおいてUDAS のβ バージョンの公開を開始し,2012 年2月に本公開を開始した.2012 年10 月以降には,UDAS をTDAS に組み込み,THEMIS ソフトウェアウェブサイトから公開することを計画している.UDAS を提供するにあたり,プログラムの動作確認作業を軽減するためのテストツールの開発も行った.さらに,IDL ライセンスを持たない研究者のために,IDL Virtual Machine 環境で走るTDAS の実行ファイルを開発し,テスト公開を開始した.これらの新しい展開により,UDAS 及びIUGONET 所属機関が所有する地上観測データの利用が促進されることが期待される.

IUGONET解析ソフトウェアの現状と今後の発展査読有り

宇宙航空研究開発機構研究開発報告 12 巻 ( 12-006 ) 頁： 63 - 70 2013年3月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：宇宙航空研究開発機構

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