87 citations · 477 across the 33 of their papers we have counts for
31 papers · 1 filter
Investigation of Solar Wind Speed Characteristics Using IPS Observations and the PFSS+SCS Model
Kyogo Tokoro, Munehito Shoda, Shinsuke Imada
Understanding the relationship between solar wind speed and global coronal magnetic field is essential for space-weather forecasting and provides key diagnostics of the underlying…
Radial evolution of Alfvén wave Parametric Decay Instability in the near-Sun solar wind: Effects of Temperature Anisotropy
Hayato Saguchi, Yohei Kawazura, Munehito Shoda +1
Parametric decay instability (PDI) of Alfvén wave is thought to play an important role in the dissipation of the large-amplitude Alfvén waves and in the heating of magnetized plasm…
Chromospheric turbulence as a regulator of stellar wind mass flux
Munehito Shoda, Tom Van Doorsselaere, Allan Sacha Brun
The mass flux of solar and stellar winds is a key quantity for stellar evolution and space weather, yet its physical regulation mechanism remains an unsolved problem. In particular…
Magnetic switchback formation: a review of proposed mechanisms
Peter F. Wyper, Jonathan Squire, Etienne Pariat +19
Magnetic switchbacks are large amplitude deflections of the magnetic field within the solar wind. They are Alfvénic in character and so are associated with a spike in velocity and…
Multi-hierarchy simulation of Riemann problem for reconnection exhausts
Keita Akutagawa, Shinsuke Imada, Munehito Shoda
Magnetic reconnection drives a wide range of astrophysical plasma phenomena, including solar flares, by converting magnetic energy into plasma energy through changes in magnetic fi…
Proposal of a Novel Physical Parameter Characterizing Solar Wind Speed in a Wave-Driven Model
Kyogo Tokoro, Munehito Shoda, Shinsuke Imada
Empirical solar wind speed models play an important role in enabling space weather forecasting with low computational cost. Among these, one model called WS model is based on the a…
Influence of kinetic effects in large-scale magnetic reconnection with multi-hierarchy simulation code KAMMUY
Keita Akutagawa, Shinsuke Imada, Munehito Shoda
Magnetic reconnection is a multiscale phenomenon where fluid- and particle-scale processes interact. The particle-in-cell (PIC) method, capable of resolving kinetic (particle-scale…
Empirical Optimization of the Source-Surface Height in the PFSS extrapolation
Munehito Shoda, Kyogo Tokoro, Daikou Shiota +1
The potential field source surface (PFSS) method is a widely used magnetic field extrapolation technique in the space weather community. The only free parameter in the PFSS method…
Can plasmoid-mediated reconnection occur in collisionless systems?
Keita Akutagawa, Shinsuke Imada, Munehito Shoda
Magnetic reconnection is a process that converts magnetic energy into plasma energy by changing the magnetic field line topology. The outstanding question is why the reconnection r…
Model of X-ray and extreme-UV emission from magnetically heated atmospheres in classical T Tauri stars: Case study of TW Hya
Munehito Shoda, Riouhei Nakatani, Shinsuke Takasao
Photoevaporation caused by X-rays and ultraviolet radiation from the central star has attracted attention as a key process driving the dispersal of protoplanetary discs. Although n…
Density fluctuation in the solar corona and solar wind: A comparative analysis of radio-occultation observations and magnetohydrodynamic simulation
Shota Chiba, Munehito Shoda, Takeshi Imamura
Recent in-situ observations and numerical models indicated various types of magnetohydrodynamic (MHD) waves contributing to the solar wind acceleration. Among them is an MHD wave d…
Assessing the capability of a model-based stellar XUV estimation
Munehito Shoda, Kosuke Namekata, Shinsuke Takasao
Stellar XUV (X-ray and extreme ultraviolet) emission drives the heating and chemical reactions in planetary atmospheres and protoplanetary disks, and therefore, a proper estimation…
Can the solar p-modes contribute to the high-frequency transverse oscillations of spicules?
Hidetaka Kuniyoshi, Munehito Shoda, Richard J. Morton +1
Lateral motions of spicules serve as vital indicators of transverse waves in the solar atmosphere, and their study is crucial for understanding the wave heating process of the coro…
Formulating Mass-Loss Rates for Sun-like Stars: A Hybrid Model Approach
Munehito Shoda, Steven R. Cranmer, Shin Toriumi
We observe an enhanced stellar wind mass-loss rate from low-mass stars exhibiting higher X-ray flux. This trend, however, does not align with the Sun, where no evident correlation…
Magnetic Tornado Properties: A Substantial Contribution to the Solar Coronal Heating via Efficient Energy Transfer
Hidetaka Kuniyoshi, Munehito Shoda, Haruhisa Iijima +1
In solving the solar coronal heating problem, it is crucial to comprehend the mechanisms by which energy is conveyed from the photosphere to the corona. Recently, magnetic tornadoe…
Reconstructing the XUV Spectra of Active Sun-like Stars Using Solar Scaling Relations with Magnetic Flux
Kosuke Namekata, Shin Toriumi, Vladimir S. Airapetian +3
Kepler Space Telescope and Transiting Exoplanet Survey Satellite unveiled that Sun-like stars frequently host exoplanets. These exoplanets are subject to fluxes of ionizing radiati…
Role of Longitudinal Waves in Alfven-wave-driven Solar/Stellar Wind
Kimihiko Shimizu, Munehito Shoda, Takeru K. Suzuki
We study the role the the p-mode-like vertical oscillation on the photosphere in driving solar winds in the framework of Alfven-wave-driven winds. By performing one-dimensional mag…
Transition of latitudinal differential rotation as a possible cause of weakened magnetic braking of solar-type stars
Takato Tokuno, Takeru K. Suzuki, Munehito Shoda
We investigate the role of latitudinal differential rotation (DR) in the spin evolution of solar-type stars. Recent asteroseismic observation detected the strong equator-fast DR in…
The Effect of the Chromospheric Temperature on Coronal Heating
Haruka Washinoue, Munehito Shoda, Takeru K. Suzuki
Recent observational and numerical studies show a variety of thermal structures in the solar chromosphere. Given that the thermal interplay across the transition region is a key to…
Stirring the Base of the Solar Wind: On Heat Transfer and Vortex Formation
Adam J. Finley, Sacha A. Brun, Mats Carlsson +3
Current models of the solar wind must approximate (or ignore) the small-scale dynamics within the solar atmosphere, however these are likely important in shaping the emerging wave-…
Role of Longitudinal Waves in Alfvén-wave-driven Solar Wind
Kimihiko Shimizu, Munehito Shoda, Takeru K. Suzuki
We revisit the role of longitudinal waves in driving the solar wind. We study how the the -mode-like vertical oscillation on the photosphere affects the properties of solar wind…
Testing the Alfvén-wave model of the solar wind with interplanetary scintillation
Munehito Shoda, Kazumasa Iwai, Daikou Shiota
Understanding the mechanism(s) of the solar wind acceleration is important in astrophysics and geophysics. A promising model of the solar wind acceleration is known as the wave/tur…
Corona and XUV emission modelling of the Sun and Sun-like stars
Munehito Shoda, Shinsuke Takasao
The X-ray and extreme-ultraviolet (EUV) emissions from the low-mass stars significantly affect the evolution of the planetary atmosphere. However, it is, observationally difficult…
Turbulent generation of magnetic switchbacks in the Alfvénic solar wind
Munehito Shoda, Benjamin D. G. Chandran, Steven R. Cranmer
One of the most important early results from the Parker Solar Probe (PSP) is the ubiquitous presence of magnetic switchbacks, whose origin is under debate. Using a three-dimensiona…