Takahiro Obara
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Takahiro Obara has a total of 5 co-authors. Here are the top co-authors by number of shared publications:
- Daikou Shiota
National Institute of Information and Communications Technology
1 shared publication - Kiyoshi Ichimoto
Kwasan and Hida Observatory, Kyoto Univ., Takayama, Japan
1 shared publication - Mitsuo Oka
Space Sciences Laboratory, University of California Berkeley, 7 Gauss Way, Berkeley, CA 94720, USA
1 shared publication - Nariaki V. Nitta
Lockheed Martin Advanced Technology Center
1 shared publication - Seiji Yashiro
The Catholic University of America, Washington, USA
1 shared publication
Latest Publications
- Open Access
- 29 January 2021
- Published by Springer Nature in Earth, Planets and Space
- Vol. 73 (1) , 1-10
Unusual enhancement of ~ 30 MeV proton flux in an ICME sheath region
In gradual Solar Energetic Particle (SEP) events, shock waves driven by coronal mass ejections (CMEs) play a major role in accelerating particles, and the energetic particle flux enhances substantially when the shock front passes by the observer. Such enhancements are historically referred to as Energetic Storm Particle (ESP) events, but it remains unclear why ESP time profiles vary significantly from event to event. In some cases, energetic protons are not even clearly associated with shocks. Here, we report an unusual, short-duration proton event detected on 5 June 2011 in the compressed sheath region bounded by an interplanetary shock and the leading edge of the interplanetary CME (or ICME) that was driving the shock. While < 10 MeV protons were detected already at the shock front, the higher-energy (> 30 MeV) protons were detected about four hours after the shock arrival, apparently correlated with a turbulent magnetic cavity embedded in the ICME sheath region.
- 29 January 2021
- Published by Springer Nature in Earth, Planets and Space
- Vol. 73 (1) , 1-10
Open AccessUnusual enhancement of ~ 30 MeV proton flux in an ICME sheath region
In gradual Solar Energetic Particle (SEP) events, shock waves driven by coronal mass ejections (CMEs) play a major role in accelerating particles, and the energetic particle flux enhances substantially when the shock front passes by the observer. Such enhancements are historically referred to as Energetic Storm Particle (ESP) events, but it remains unclear why ESP time profiles vary significantly from event to event. In some cases, energetic protons are not even clearly associated with shocks. Here, we report an unusual, short-duration proton event detected on 5 June 2011 in the compressed sheath region bounded by an interplanetary shock and the leading edge of the interplanetary CME (or ICME) that was driving the shock. While < 10 MeV protons were detected already at the shock front, the higher-energy (> 30 MeV) protons were detected about four hours after the shock arrival, apparently correlated with a turbulent magnetic cavity embedded in the ICME sheath region.