研究者詳細 - 大塚　雄一

論文 - 大塚　雄一

分割表示 496 件中 241 - 260 件目／全件表示 >>

Duskside enhancement of equatorial zonal electric field response to convection electric fields during the St. Patrick's Day storm on 17 March 2015 査読有り Open Access

Ram, ST; Yokoyama, T; Otsuka, Y; Shiokawa, K; Sripathi, S; Veenadhari, B; Heelis, R; Ajith, KK; Gowtam, VS; Gurubaran, S; Supnithi, P; Le Huy, M

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 121 巻 ( 1 ) 頁： 538 - 548 2016年1月

ISS-IMAPによる大気光波状構造の観測 Open Access

齊藤昭則, 穂積裕太, 坂野井健, S. Perwitasari, 吉川一朗, 山崎敦, 大塚雄一, 山本衛

第29回大気圏シンポジウム: 講演集録 2016年

TEC variation during high and low solar activities over South American sector 査読有り

Jonah, OF; de Paula, ER; Muella, MTAH; Dutra, SLG; Kherani, EA; Negreti, PMS; Otsuka, Y

JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS 135 巻頁： 22 - 35 2015年12月

A direct link between chorus emissions and pulsating aurora on timescales from milliseconds to minutes: A case study at subauroral latitudes 査読有り Open Access

Ozaki, M; Yagitani, S; Sawai, K; Shiokawa, K; Miyoshi, Y; Kataoka, R; Ieda, A; Ebihara, Y; Connors, M; Schofield, I; Katoh, Y; Otsuka, Y; Sunagawa, N; Jordanova, VK

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 120 巻 ( 11 ) 頁： 9617 - 9631 2015年11月

Coordinated airglow observations between IMAP/VISI and a ground-based all-sky imager on concentric gravity wave in the mesopause 査読有り Open Access

Perwitasari, S; Sakanoi, T; Yamazaki, A; Otsuka, Y; Hozumi, Y; Akiya, Y; Saito, A; Shiokawa, K; Kawamura, S

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 120 巻 ( 11 ) 頁： 9706 - 9721 2015年11月

Multi-instrument, high-resolution imaging of polar cap patch transportation 査読有り Open Access

Thomas, EG; Hosokawa, K; Sakai, J; Baker, JBH; Ruohoniemi, JM; Taguchi, S; Shiokawa, K; Otsuka, Y; Coster, AJ; St-Maurice, JP; McWilliams, KA

RADIO SCIENCE 50 巻 ( 9 ) 頁： 904 - 915 2015年9月

Plasma bubble monitoring by TEC map and 630 nm airglow image 査読有り Open Access

Takahashi, H; Wrasse, CM; Otsuka, Y; Ivo, A; Gomes, V; Paulino, I; Medeiros, AF; Denardini, CM; Sant'Anna, N; Shiokawa, K

JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS 130 巻頁： 151 - 158 2015年8月

Statistical study of auroral fragmentation into patches 査読有り Open Access

Hashimoto, A; Shiokawa, K; Otsuka, Y; Oyama, S; Nozawa, S; Hori, T; Lester, M; Johnsen, MG

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 120 巻 ( 8 ) 頁： 6207 - 6217 2015年8月

Fresh and evolutionary-type field-aligned irregularities generated near sunrise terminator due to overshielding electric fields 査読有り Open Access

Ram, ST; Ajith, KK; Yamamoto, M; Otsuka, Y; Yokoyama, T; Niranjan, K; Gurubaran, S

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 120 巻 ( 7 ) 頁： 5922 - 5930 2015年7月

Effects of pre-reversal enhancement of E x B drift on the latitudinal extension of plasma bubble in Southeast Asia 査読有り Open Access

Abadi, P; Otsuka, Y; Tsugawa, T

EARTH PLANETS AND SPACE 67 巻 2015年5月

Airglow-imaging observation of plasma bubble disappearance at geomagnetically conjugate points 査読有り Open Access

Shiokawa, K; Otsuka, Y; Lynn, KJW; Wilkinson, P; Tsugawa, T

EARTH PLANETS AND SPACE 67 巻頁： 1 - 12 2015年3月

Geomagnetically conjugate observation of plasma bubbles and thermospheric neutral winds at low latitudes 査読有り

Fukushima, D; Shiokawa, K; Otsuka, Y; Nishioka, M; Kubota, M; Tsugawa, T; Nagatsuma, T; Komonjinda, S; Yatini, CY

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 120 巻 ( 3 ) 頁： 2222 - 2231 2015年3月

Explicit characteristics of evolutionary-type plasma bubbles observed from Equatorial Atmosphere Radar during the low to moderate solar activity years 2010-2012 査読有り

Ajith, KK; Ram, ST; Yamamoto, M; Yokoyama, T; Gowtam, VS; Otsuka, Y; Tsugawa, T; Niranjan, K

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 120 巻 ( 2 ) 頁： 1371 - 1382 2015年2月

CDF data archive and integrated data analysis platform for ERG-related ground data developed by ERG Science Center (ERG-SC) 査読有り

Hori, T, Y. Miyashita, Y. Miyoshi, K. Seki, T. Segawa, Y.-M. Tanaka, K. Keika, M. Shoji, I. Shinohara, K. Shiokawa, Y. Otsuka, S. Abe, A. Yoshikawa, K. Yumoto, Y. Obana, N. Nishitani, A. S. Yukimatu, T. Nagatsuma, M. Kunitake, K. Hosokawa, Y. Ogawa, K. T. Murata, M. Nosé, H. Kawano, T. Sakanoi

宇宙科学情報解析論文誌 JAXA-RR-14-009 巻頁： 75 - 90 2015年

GAST-D flight experiment results with disturbed and quiet ionospheric conditions 査読有り

Susumu Saito, Takayuki Yoshihara, Atsushi Kezuka, Shinji Saitoh, Sonosuke Fukushima, Yuichi Otsuka

PROCEEDINGS OF THE 28TH INTERNATIONAL TECHNICAL MEETING OF THE SATELLITE DIVISION OF THE INSTITUTE OF NAVIGATION (ION GNSS+ 2015) 頁： 1494 - 1499 2015年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：INST NAVIGATION

GAST-D ground prototype and and GAST-D airborne experimental subsystem have been developed. The GAST-D ground prototype was installed at New Ishigaki Airport located in the low magnetic latitude region. With the ground prototype and the airborne experimental system, GAST-D flight experiments in the low magnetic latitude region under ionospheric quiet and disturbed conditions for the first time in the world.
Two flight campaigns were conducted in March and September 2014. In the campaign carried out in September 2014, the vertical error performances were comparable between ionospheric quiet and disturbed condition. However, availability degradation during the severely disturbed condition is an issue. The DSIGMA monitor which is one of the airborne integrity monitors was confirmed by all-sky airglow measurements to react ionospheric disturbance.
The next steps of the study include parameter tuning of the ground prototype and airborne experimental system to enhance service availability during ionospheric disturbed conditions.

Web of Science

Direct observations of blob deformation during a substorm 査読有り

T. Ishida, Y. Ogawa, A. Kadokura, K. Hosokawa, Y. Otsuka

ANNALES GEOPHYSICAE 33 巻 ( 5 ) 頁： 525 - 530 2015年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：COPERNICUS GESELLSCHAFT MBH

Ionospheric blobs are localized plasma density enhancements, which are mainly produced by the transportation process of plasma. To understand the deformation process of a blob, observations of plasma parameters with good spatial-temporal resolution are desirable. Thus, we conducted the European Incoherent Scatter radar observations with high-speed meridional scans (60-80 s) during October and December 2013, and observed the temporal evolution of a blob during a substorm on 4 December 2013. This paper is the first report of direct observations of blob deformation during a substorm. The blob deformation arose from an enhanced plasma flow shear during the substorm expansion phase, and then the blob split into two smaller-scale blobs, whose scale sizes were more than similar to 100 km in latitude. Our analysis indicates that the Kelvin-Helmholtz instability and dissociative recombination could have deformed the blob structure.

DOI： 10.5194/angeocom-33-525-2015

Web of Science

Climatology of Equatorial Plasma Bubble Observed by MyRTKnet over the Years 2008-2013 査読有り

S. M. Buhari, M. Abdullah, T. Yokoyama, A. M. Hasbi, Y. Otsuka, M. Nishioka, S. A. Bahari, T. Tsugawa

2015 INTERNATIONAL CONFERENCE ON SPACE SCIENCE AND COMMUNICATION (ICONSPACE) 頁： 101 - 105 2015年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Malaysia Real-Time Kinematics GNSS Network (MyRTKnet) which consists of 78 GPS receivers was used to investigate the occurrence of equatorial plasma bubble (EPB) along 96 degrees E - 120 degrees E longitude. In this study, we present the monthly occurrence rate of EPB along the geographical longitudes of 96 degrees E - 120 degrees E for a half of solar cycle period (2008 - 2013). A 2D map of rate of TEC change index (ROTI) projected at 300 km altitude was derived from the signal paths between GPS satellites and the receivers. A ROTI keogram for one day period was obtained from the east-west cross section of the 2D ROTI maps at 4 degrees N for every 5 min. The occurrence day of EPB was determined from the keogram by the existence of ROTI larger than 0.1 TECU/min within the 96 degrees E - 120 degrees E longitude. The results show that the occurrence of EPB along the 96 degrees E - 120 degrees E has maximum during equinoctial months and is consistent with previous studies. The occurrence rate of EPB during equinoctial months shows similar characteristics in low and high solar activity due to the broad observational coverage of the MyRTKnet. In contrast, the occurrence rate of EPB during solstice months shows significant relation with solar activity. Solstice months recorded high occurrence rate of EPB in high solar activity that might be attributed to post-midnight irregularities.

DOI： 10.1109/IconSpace.2015.7283752

Web of Science

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

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

EARTH PLANETS AND SPACE 66 巻 2014年12月

CME front and severe space weather 査読有り Open Access

Balan, N; Skoug, R; Ram, ST; Rajesh, PK; Shiokawa, K; Otsuka, Y; Batista, IS; Ebihara, Y; Nakamura, T

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 119 巻 ( 12 ) 2014年12月

Continuous generation and two-dimensional structure of equatorial plasma bubbles observed by high-density GPS receivers in Southeast Asia 査読有り Open Access

Buhari, SM; Abdullah, M; Hasbi, AM; Otsuka, Y; Yokoyama, T; Nishioka, M; Tsugawa, T

JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 119 巻 ( 12 ) 2014年12月

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