Related papers: Flux emergence in a magnetized convection zone
We present a three-dimensional numerical model for the generation and evolution of the magnetic field in the solar convection zone, in which sunspots are produced and contribute to the cyclic reversal of the large-scale magnetic field. We…
The current dynamo paradigm for the Sun and sun-like stars places the generation site for strong toroidal magnetic structures deep in the solar interior. Sunspots and star-spots on sun-like stars are believed to arise when sections of these…
This study aims at investigating the ability of strong interactions between magnetic field concentrations during their rise through the convection zone to produce complex active regions at the solar surface. To do so, we perform numerical…
Magnetic flux ropes (MFRs) constitute the core structure of coronal mass ejections (CMEs), but hot debates remain on whether the MFR forms before or during solar eruptions. Furthermore, how flare reconnection shapes the erupting MFR is…
Context. Data-constrained models incorporate observed photospheric magnetic fields. However, due to the lack of magnetic field information in the rest of the solar atmosphere, models rely on extrapolations that, in most cases, neglect the…
A magnetic flux tube may be considered both as a separate body and as a confined field. As a field, it is affected both by the cyclonic convection ($\alpha$-effect) and differential rotation ($\Omega$-effect). As a body, the tube…
The polarity of the toroidal magnetic field in the solar convection zone periodically reverses in the course of the 11/22-year solar cycle. Among the various processes that contribute to the removal of `old-polarity' toroidal magnetic flux…
We present three-dimensional numerical simulations of the rise and fragmentation of twisted, initially horizontal magnetic flux tubes which evolve into emerging Omega-loops. The flux tubes rise buoyantly through an adiabatically stratified…
I present results from a set of 3D spherical-shell MHD simulations of the buoyant rise of active region flux tubes in the solar interior which put new constraints on the initial twist of the subsurface tubes in order for them to emerge with…
Spherical shell dynamo models based on rotating convection show that the flow within the tangent cylinder is dominated by an off-axis plume that extends from the inner core boundary to high latitudes and drifts westward. Earlier studies…
{In order to understand the emergence of the active region, we investigate the emerging process and magnetic properties of a naked anti-Hale active region during the period between August 24 to 25, 2018.} {Using the data from Helioseismic…
We investigate the relations between tachocline-based dynamos and the surface flux transport mechanisms in stars with outer convection zones. Using our combined models of flux generation and transport, we demonstrate the importance of the…
Flux ropes are generally believed to be core structures of solar eruptions that are significant for the space weather, but their formation mechanism remains intensely debated. We report on the formation of a tiny flux rope beneath clusters…
Current coronal mass ejection (CME) models set their lower boundary to be in the lower corona. They do not calculate accurately the transfer of free magnetic energy from the convection zone to the magnetically dominated corona because they…
We simulate the rise through the upper convection zone and emergence through the solar surface of initially uniform, untwisted, horizontal magnetic flux with the same entropy as the non-magnetic plasma that is advected into a domain 48 Mm…
Magnetic active regions on the Sun are harbingers of space weather events. Understanding the physics of how they form and evolve will improve space weather forecasting. Our aim is to characterise the surface magnetic field and flows for a…
The combination of magnetohydrodynamic (MHD) simulation and multi-wavelength observations is an effective way to study mechanisms of magnetic flux rope eruption. We develop a data-driven MHD model using the zero-$\beta$ approximation. The…
Combining the Solar Dynamics Observatory and the New Vacuum Solar Telescope observations, we study a confined flare triggered by a rising flux rope within the trailing sunspots of active region 12733. The flux rope lying above the sheared…
We review recent advances in modeling global-scale convection and dynamo processes with the Anelastic Spherical Harmonic (ASH) code. In particular, we have recently achieved the first global-scale solar convection simulations that exhibit…
Sunspots are obvious observable manifestations of the toroidal magnetic field generated through the dynamo in the convection zone. They appear in different sizes, having a wide distribution in their area. We analyse the sunspot group area…