150 citations · 1.2k across the 25 of their papers we have counts for
25 papers
Angular momentum transport in the convection zone of a 3D MHD simulation of a rapidly rotating core-collapse progenitor
Ryota Shimada, Lucy O. McNeill, Vishnu Varma +3
Rotation and magnetic fields in the cores of evolved massive stars in their final phase are thought to play an important role in the subsequent supernova explosion and the formatio…
Convective velocity suppression via the enhancement of subadiabatic layer: Role of the effective Prandtl number
Y. Bekki, H. Hotta, T. Yokoyama
It has recently been recognized that the convective velocities achieved in the current solar convection simulations might be over-estimated. The newly-revealed effects of the preva…
Observational signatures of transverse MHD waves and associated dynamic instabilities
Patrick Antolin, Ineke De Moortel, Tom Van Doorsselaere +1
MHD waves permeate the solar atmosphere and constitute potential coronal heating agents. Yet, the waves detected so far may be but a small subset of the true existing wave power. D…
Double-Cell Type Solar Meridional Circulation Based on Mean-Field Hydrodynamic Model
Yuto Bekki, Takaaki Yokoyama
The main object of the paper is to present the condition of the non-diffusive part of the Reynolds stress for driving the double-cell structure of the solar meridional circulation,…
Modelling observed decay-less oscillations as resonantly enhanced Kelvin-Helmholtz vortices from transverse MHD waves and their seismological application
Patrick Antolin, Ineke De Moortel, Tom Van Doorsselaere +1
In the highly structured solar corona, resonant absorption is an unavoidable mechanism of energy transfer from global transverse MHD waves to local azimuthal Alfvén waves. Due to i…
Detection of Flux Emergence, Splitting, Merging, and Cancellation of Network Fields. II Apparent Unipolar Flux Change and Cancellation
Y. Iida, H. Hagenaar, T. Yokoyama
In this second paper in the series, we investigate occurrence frequencies of apparent unipolar processes, cancellation, and emergence of patch structures in quiet regions. Apparent…
Effect of coronal temperature on the scale of solar chromospheric jets
H. Iijima, T. Yokoyama
We investigate the effect of coronal temperature on the formation process of solar chromospheric jets using two-dimensional magnetohydrodynamic simulations of the region from the u…
Apparent cross-field superslow propagation of magnetohydrodynamic waves in solar plasmas
T. Kaneko, M. Goossens, R. Soler +4
In this paper we show that the phase mixing of continuum Alfvén waves and/or continuum slow waves in magnetic structures of the solar atmosphere as, e.g., coronal arcades, can crea…
Resonant Absorption of Transverse Oscillations and Associated Heating in a Solar Prominence. II- Numerical aspects
Patrick Antolin, Takenori J. Okamoto, Bart De Pontieu +3
Transverse magnetohydrodynamic (MHD) waves are ubiquitous in the solar atmosphere and may be responsible for generating the Sun's million-degree outer atmosphere. However, direct e…
Efficient small-scale dynamo in solar convection zone
H. Hotta, M. Rempel, T. Yokoyama
We investigate small-scale dynamo action in the solar convection zone through a series of high resolution MHD simulations in a local Cartesian domain with 1 (solar radius)…
High-resolution calculation of the solar global convection with the reduced speed of sound technique: II. Near surface shear layer with the rotation
H. Hotta, M. Rempel, T. Yokoyama
We present a high-resolution, highly stratified numerical simulation of rotating thermal convection in a spherical shell. Our aim is to study in detail the processes that can maint…
Fine strand-like structure in the solar corona from MHD transverse oscillations
P. Antolin, T. Yokoyama, T. Van Doorsselaere
Current analytical and numerical modelling suggest the existence of ubiquitous thin current sheets in the corona that could explain the observed heating requirements. On the other…
High-resolution calculations of the solar global convection with the reduced speed of sound technique: I. The structure of the convection and the magnetic field without the rotation
H. Hotta, M. Rempel, T. Yokoyama
We carry out non-rotating high-resolution calculations of the solar global convection, which resolve convective scales of less than 10 Mm. To cope with the low Mach number conditio…
Generation of twist on magnetic flux tubes at the base of the solar convection zone
H. Hotta, T. Yokoyama
Using two-dimensional magnetohydrodynamics calculations, we investigate a twist gen- eration mechanism on a magnetic flux tube at the base of the solar convection zone based on the…
Magnetic field intensification by three-dimensional explosion process
H. Hotta, M. Rempel, T. Yokoyama
We investigate an intensification mechanism for the magnetic field near the base of the solar convection zone that does not rely on differential rotation. Such mechanism in additio…
Detection of flux emergence, splitting, merging, and cancellation of network field. I Splitting and Merging
Y. Iida, H. Hagenaar, T. Yokoyama
Frequencies of magnetic patch processes on supergranule boundary, namely flux emergence, splitting, merging, and cancellation, are investigated through an automatic detection. We u…
Estimation of turbulent diffusivity with direct numerical simulation of stellar convection
H. Hotta, Y. Iida, T. Yokoyama
We investigate the value of horizontal turbulent diffusivity η by numerical calculation of thermal convection. In this study, we introduce a new method whereby the turbulent diffus…
Detection of the Horizontal Divergent Flow prior to the Solar Flux Emergence
S. Toriumi, K. Hayashi, T. Yokoyama
It is widely accepted that solar active regions including sunspots are formed by the emerging magnetic flux from the deep convection zone. In previous numerical simulations, we fou…
Large-scale 3D MHD simulation on the solar flux emergence and the small-scale dynamic features in an active region
S. Toriumi, T. Yokoyama
We have performed a three-dimensional magnetohydrodynamic simulation to study the emergence of a twisted magnetic flux tube from -20,000 km of the solar convection zone to the coro…
Numerical Calculation of Convection with Reduced Speed of Sound Technique
H. Hotta, M. Rempel, T. Yokoyama +2
Context. The anelastic approximation is often adopted in numerical calculation with low Mach number, such as stellar internal convection. This approximation requires frequent globa…
Modeling of differential rotation in rapidly rotating solar-type stars
Hideyuki Hotta, Takaaki Yokoyama
We investigate differential rotation in rapidly rotating solar-type stars by means of an axisymmetric mean field model that was previously applied to the sun. This allows us to cal…
Numerical Experiments on the Two-step Emergence of Twisted Magnetic Flux Tubes in the Sun
Shin Toriumi, Takaaki Yokoyama
We present the new results of the two-dimensional numerical experiments on the cross-sectional evolution of a twisted magnetic flux tube rising from the deeper solar convection zon…
Solar parity issue with flux-transport dynamo
H. Hotta, T. Yokoyama
We investigated the dependence of the solar magnetic parity between the hemispheres on two important parameters, the turbulent diffusivity and the meridional flow, by means of axis…
Two-step Emergence of the Magnetic Flux Sheet from the Solar Convection Zone
Shin Toriumi, Takaaki Yokoyama
We perform two-dimensional MHD simulations on the solar flux emergence. We set the initial magnetic flux sheet at z=-20,000 km in the convection zone. The flux sheet rises through…