192 citations · 779 across the 28 of their papers we have counts for
25 papers · 1 filter
Simulations of solar and stellar dynamos and their theoretical interpretation
Petri J. Käpylä, Matthew K. Browning, Allan Sacha Brun +2
We review the state of the art of three dimensional numerical simulations of solar and stellar dynamos. We summarize fundamental constraints of numerical modelling and the techniqu…
The Puzzling Structure of Solar Convection: Window into the Dynamo
Nicholas A. Featherstone, Kyle C. Augustson, Jonathan M. Aurnou +25
The operation of the solar dynamo, with all of its remarkable spatio-temporal ordering, remains an outstanding problem of modern solar physics. A number of mechanisms that might pl…
Global simulations of Tayler instability in stellar interiors: a long-time multi-stage evolution of the magnetic field
G. Monteiro, G. Guerrero, F. Del Sordo +2
Magnetic fields have been observed in massive Ap/Bp stars and presumably are also present in the radiative zone of solar-like stars. Yet, to date there is no clear understanding of…
Implicit large eddy simulations of global solar convection: effects of numerical resolution in non-rotating and rotating cases
G. Guerrero, A. M. Stejko, A. G. Kosovichev +2
Simulating deep solar convection and its coupled mean-field motions is a formidable challenge where few observational results constrain models that suffer from the non-physical inf…
Constraining Global Solar Models through Helioseismic Analysis
Andrey M. Stejko, Alexander G. Kosovichev, Nicholas A. Featherstone +4
Global hydrodynamic simulations of internal solar dynamics have focused on replicating the conditions for solar-like differential rotation and meridional circulation using the resu…
Identification of inertial modes in the solar convection zone
Santiago Andrés Triana, Gustavo Guerrero, Ankit Barik +1
The observation of global acoustic waves (p modes) in the Sun has been key to unveiling its internal structure and dynamics. A different kind of wave, known as sectoral Rossby mode…
Advances and Challenges in Observations and Modeling of the Global-Sun Dynamics and Dynamo
A. G. Kosovichev, G. Guerrero, A. M. Stejko +2
Computational heliophysics has shed light on the fundamental physical processes inside the Sun, such as the differential rotation, meridional circulation, and dynamo-generation of…
Leptocline as a Shallow Substructure of Near-Surface Shear Layer in 3D Radiative Hydrodynamic Simulations
Irina N. Kitiashvili, Alexander G. Kosovichev, Alan A. Wray +2
Understanding effects driven by rotation in the solar convection zone is essential for many problems related to solar activity, such as the formation of differential rotation, meri…
Numerical convergence of 2D solar convection in implicit large-eddy simulations
H. D. Nogueira, G. Guerrero, P. K. Smolarkiewicz +1
Large-eddy simulations (LES) and implicit LES (ILES) are wise and affordable alternatives to the unfeasible direct numerical simulations (DNS) of turbulent flows at high Reynolds n…
Global simulations of stellar dynamos
G Guerrero
The dynamo mechanism, responsible for the solar magnetic activity, is still an open problem in astrophysics. Different theories proposed to explain such phenomena have failed in re…
3D MHD Modeling of the Impact of Subsurface Stratification on the Solar Dynamo
Andrey M. Stejko, Gustavo Guerrero, Alexander G. Kosovichev +1
Various models of solar subsurface stratification are tested in the global EULAG-MHD solver to simulate diverse regimes of near-surface convective transport. Sub- and superadiabaci…
Global simulations of Tayler instability in stellar interiors: The stabilizing effect of gravity
G. Guerrero, F. Del Sordo, A. Bonanno +1
Unveiling the evolution of toroidal field instability, known as Tayler instability, is essential to understand the strength and topology of the magnetic fields observed in early-ty…
What sets the magnetic field strength and cycle period in solar-type stars?
G. Guerrero, B. Zaire, P. K. Smolarkiewicz +3
Two fundamental properties of stellar magnetic fields have been determined by observations for solar-like stars with different Rossby numbers (Ro), namely, the magnetic field stren…
Magnetic field generation in PMS stars with and without radiative core
Bonnie Zaire, Gustavo Guerrero, Alexander Kosovichev +2
Recent observations of the magnetic field in pre-main sequence stars suggest that the magnetic field topology changes as a function of age. The presence of a tachocline could be an…
Meridional Circulation Dynamics in a Cyclic Convective Dynamo
D. Passos, M. Miesch, G. Guerrero +1
Surface observations indicate that the speed of the solar meridional circulation in the photosphere varies in anti-phase with the solar cycle. The current explanation for the sourc…
3D Global MHD Modeling of Solar Subsurface Convection
Andrey M. Stejko, Gustavo Guerrero, Alexander G. Kosovichev +1
Various models of solar sub-surface stratification are tested in the global EULAG-MHD solver to simulate diverse regimes of near-surface convective transport. Sub- and superadiabac…
On the role of tachoclines in solar and stellar dynamos
G. Guerrero, P. K. Smolarkiewicz, E. M. de Gouveia Dal Pino +2
Rotational shear layers at the boundary between radiative and convective zones, tachoclines, play a key role in the process of magnetic field generation in solar-like stars. We pre…
Differential rotation in solar-like stars from global simulations
G. Guerrero, P. K. Smolarkiewicz, A. G. Kosovichev +1
To explore the physics of large-scale flows in solar-like stars, we perform 3D anelastic simulations of rotating convection for global models with stratification resembling the sol…
Solar differential rotation: hints to reproduce a near-surface shear layer in global simulations
G. Guerrero, P. K. Smolarkiewicz, A. Kosovichev +1
Convective turbulent motions in the solar interior, as well as the mean flows resulting from them, determine the evolution of the solar magnetic field. With the aim to get a better…
Cycles and cycle modulations
Axel Brandenburg, Gustavo Guerrero
Some selected concepts for the solar activity cycle are briefly reviewed. Cycle modulations through a stochastic alpha effect are being identified with limited scale separation rat…
Plasma flow vs. magnetic feature-tracking speeds in the Sun
G. Guerrero, M. Rheinhardt, A. Brandenburg +1
We simulate the magnetic feature tracking (MFT) speed using advective-diffusive transport models in both one and two dimensions. By depositing magnetic bipolar regions at different…
Reynolds stress and heat flux in spherical shell convection
P. J. Käpylä, M. J. Mantere, G. Guerrero +2
(abridged) Context. Turbulent fluxes of angular momentum and heat due to rotationally affected convection play a key role in determining differential rotation of stars. Here we per…
Can catastrophic quenching be alleviated by separating shear and alpha effect?
Piyali Chatterjee, Axel Brandenburg, Gustavo Guerrero
The small-scale magnetic helicity produced as a by-product of the large-scale dynamo is believed to play a major role in dynamo saturation. In a mean-field model the generation of…
Magnetic helicity fluxes in interface and flux transport dynamos
Piyali Chatterjee, Gustavo Guerrero, Axel Brandenburg
Dynamos in the Sun and other bodies tend to produce magnetic fields that possess magnetic helicity of opposite sign at large and small scales, respectively. The build-up of magneti…