On Dynamo-Metamorphism

Snow metamorphism: A fractal approach.

Snow is a porous disordered medium consisting of air and three water phases: ice, vapor, and liquid. The ice phase consists of an assemblage of grains, ice matrix, initially arranged over a random load bearing skeleton. The quantitative relationship between density and morphological characteristics of different snow microstructures is still an open issue. In this work, a three-dimensional fract...

On the dynamo driven accretion disks

We add the α− effect in the dynamo driven accretion disk model proposed by Tout & Pringle (1992), i. e., a dynamo model depends on the physical processes such as Parker instability, Balbus-Hawley instability, magnetic field reconnection and α − ω mean field dynamo as well. The α− effect in the dynamo mechanism is determined by the strength of turbulence of the accretion flow. When the turbulent...

Influence of turbulence on the dynamo threshold.

We use direct and stochastic numerical simulations of the magnetohydrodynamic equations to explore the influence of turbulence on the dynamo threshold. In the spirit of the Kraichnan-Kazantsev model, we model the turbulence by a noise, with given amplitude, injection scale, and correlation time. The addition of a stochastic noise to the mean velocity significantly alters the dynamo threshold an...

DYNAMO: A Dynamic Architectural Memory On-line

Dynamo Mechanisms

Dynamo theory is reviewed with particular emphasis on recent developments. There now seems to be a strong case for dynamo eeects that are driven by the magnetic eld itself. This is linked to recent interpretations of the observed stellar cycle periods which suggest that the ratio of cycle frequency to rotational frequency increases, up to some point, with stellar chromospheric activity. This ra...