Stochastic analysis of subcritical amplification of magnetic energy in a turbulent dynamo / Fedotov S,Bashkirtseva I,Ryashko L // PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS. - 2004. - V. 342, l. 3-4. - P. 491-506.

ISSN/EISSN:

0378-4371 / нет данных

Type:

Article

Abstract:

We present and analyze a simplified stochastic alphaOmega-dynamo model which is designed to assess the influence of additive and multiplicative noises, non-normality of dynamo equation, and nonlinearity of the a-effect and turbulent diffusivity, on the generation of a large-scale magnetic field in the subcritical case. Our model incorporates random fluctuations in the a-parameter and additive noise arising from the small-scale fluctuations of magnetic and turbulent velocity fields. We show that the noise effects along with non-normality can lead to the stochastic amplification of the magnetic field even in the subcritical case. The criteria for the stochastic instability during the early kinematic stage are established and the critical value for the intensity of multiplicative noise due to a-fluctuations is found. We obtain numerical solutions of nonlinear stochastic differential equations and find the series of phase transitions induced by random fluctuations in the a-parameter. (C) 2004 Elsevier B.V. All rights reserved.

Author keywords:

magnetic field; non-normality; stochastic amplification FIELD; TRANSITION; STABILITY; MODEL; FLUCTUATIONS; GENERATION

DOI:

10.1016/j.physa.2004.05.084

Web of Science ID:

ISI:000224311800007

Соавторы в МНС:

Другие поля

Поле	Значение
Month	NOV 1
Publisher	ELSEVIER SCIENCE BV
Address	PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Language	English
Keywords-Plus	FIELD; TRANSITION; STABILITY; MODEL; FLUCTUATIONS; GENERATION
Research-Areas	Physics
Web-of-Science-Categories	Physics, Multidisciplinary
Author-Email	s.fedotov@umist.ac.uk
ResearcherID-Numbers	Fedotov, Sergei/H-5880-2012
Number-of-Cited-References	37
Journal-ISO	Physica A
Doc-Delivery-Number	860BG