相关论文: Building and Maintaining a Solar Tachocline throug…

Recent analyses of the helioseismic observations indicate that the previously observed surface torsional oscillations with periods of about 11 years extend significantly downwards into the solar convective zone. Furthermore, there are…

The solar tachocline at the bottom of the convection zone is an important region for the dynamics of the Sun and the solar dynamo. In this region, the sound speed inferred by global helioseismology exhibits a bump of approximately 0.4%…

Helioseismology has provided very detailed inferences about rotation of the solar interior. Within the convection zone the rotation rate roughly shares the latitudinal variation seen in the surface differential rotation. The transition to…

We present nonlinear three-dimensional simulations of the stably-stratified portion of the solar tachocline in which the rotational shear is maintained by mechanical forcing. When a broad toroidal field profile is specified as an initial…

We assess the global-scale dynamo action achieved in a simulation of a sun-like star rotating at three times the solar rate. The 3-D MHD Anelastic Spherical Harmonic code, using slope-limited diffusion, is employed to capture convection and…

The meridional circulation of the Sun, which is observed to be poleward at the surface, should have a return flow at some depth. Since large-scale flows like the differential rotation and the meridional circulation are driven by turbulent…

It has long been known that solar-type stars undergo significant spin-down, via magnetic braking, during their Main-Sequence lifetimes. However, magnetic braking only operates on the surface layers; it is not yet completely understood how…

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 three-dimensional, hydrodynamic stability of the solar tachocline is investigated based on a rotation profile as a function of both latitude and radius. By varying the amplitude of the latitudinal differential rotation, we find linear…

A new set of accurately measured frequencies of solar oscillations are used to infer the rotation rate inside the Sun, as a function of radial distance as well as latitude. We have adopted a regularized least squares technique with…

Young solar-type stars rotate rapidly and many are magnetically active; some undergo magnetic cycles similar to the 22-year solar activity cycle. We conduct simulations of dynamo action in rapidly rotating suns with the 3D MHD anelastic…

Rather weak fossil magnetic fields in the radiative core can produce the solar tachocline if the field is poloidal and almost horizontal in the tachocline region, i.e. if the field is confined within the core. This particular field geometry…

Core convection and dynamo activity deep within rotating A-type stars of 2 solar masses are studied with 3--D nonlinear simulations. Our modeling considers the inner 30% by radius of such stars, thus capturing within a spherical domain the…

The intense turbulence present in the solar convection zone is a major challenge to both theory and simulation as one tries to understand the origins of the striking differential rotation profile with radius and latitude that has been…

We study the physics of the solar tachocline and related MHD instabilities. We have performed 3-D MHD simulations of the solar radiative interior to check whether a fossil magnetic field is able to prevent the spread of the tachocline.…

The toroidal magnetic field is assumed to be generated in the tachocline in most Babcock-Leighton (BL)-type solar dynamo models, in which the poloidal field is produced by the emergence and subsequent dispersal of sunspot groups. However,…

Some established views of the solar magnetic cycle are discussed critically, with focus on two aspects at the core of most models: the role of convective turbulence, and the role of the `tachocline' at the base of the convection zone. The…

Regions of quiet Sun generally exhibit a complex distribution of small-scale magnetic field structures, which interact with the near-surface turbulent convective motions. Furthermore, it is probable that some of these magnetic fields are…

We review recent insights into the dynamics of the solar convection zone obtained from global numerical simulations, focusing on two recent developments in particular. The first is quasi-cyclic magnetic activity in a long-duration dynamo…

The form of the solar meridional circulation is a very important ingredient for mean field flux transport dynamo models. Yet a shroud of mystery still surrounds this large-scale flow, given that its measurement using current helioseismic…