Study of stochastic fluctuations in a shell dynamo

Autores
<div class="autor_fcen" id="5788">Mininni, P.D.</div>; <div class="autor_fcen" id="3802">Gómez, D.O.</div>
Año de publicación
2002
Idioma
inglés
Tipo de recurso
artículo
Estado
Versión publicada
Descripción
We present a one-dimensional αω-dynamo model to study the role of stochastic fluctuations in nonlinear kinematic dynamos. We introduce nonlinearities in the form of α-quenching and consider the effect of a meridional flow. Solutions are seen to settle down to a nonlinear periodic mode with a given amplitude. We show that the system displays relaxation oscillations that are in good agreement with the oscillations observed in the sunspot number time series. Irregularities are generated by adding a random forcing term to the αcoefficient to simulate the spatial and temporal complexity of the turbulent motions in the dynamo region. These fluctuations induce amplitude and cycle period variability, fluctuations in the dividing line between polarities around the equator, emergence of regions of reverse polarity, and north-south asymmetries. These results are in good agreement with observations and can be explained as the interaction of the deterministic solution with overtones excited by noise.
Fil:Mininni, P.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Gómez, D.O. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fuente
Astrophys. J. Lett. 2002;573(1 I):454-463
Materia
MHD
Sun: magnetic fields
Nivel de accesibilidad
Acceso abierto
Licencia
http://creativecommons.org/licenses/by/2.5/ar
Repositorio
Biblioteca Digital (UBA-FCEN)
Institución
Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales
OAI Identificador
snrd:HASH011ef3c3f5ad3e56eba19bdf