Publications by authors named "Mitsuo Oka"

Article Synopsis
  • Particles in space can reach very high energy levels during explosive events, and magnetic reconnection is a key process in understanding how this happens in Earth's magnetosphere.
  • Recent spacecraft missions have improved our ability to study particle acceleration at specific structures, revealing important insights into the mechanisms at play.
  • Further research is necessary to fully comprehend particle acceleration, particularly regarding energy distribution and the role of turbulence, and to compare findings with other plasma environments like those in solar and astrophysical contexts.
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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.

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Global-scale energy flow throughout Earth's magnetosphere is catalyzed by processes that occur at Earth's magnetopause (MP). Magnetic reconnection is one process responsible for solar wind entry into and global convection within the magnetosphere, and the MP location, orientation, and motion have an impact on the dynamics. Statistical studies that focus on these and other MP phenomena and characteristics inherently require MP identification in their event search criteria, a task that can be automated using machine learning so that more man hours can be spent on research and analysis.

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