corner
corner
APS » Journals » Phys. Rev. Lett. » Volume 100 » Issue 18
< Previous Article | Next Article >

Phys. Rev. Lett. 100, 184501 (2008) [4 pages]

Generation of Magnetic Field by Combined Action of Turbulence and Shear

Download: PDF (293 kB) Buy this article Export: BibTeX or EndNote (RIS)

T. A. Yousef1, T. Heinemann1, A. A. Schekochihin2, N. Kleeorin3, I. Rogachevskii3, A. B. Iskakov4,2,5, S. C. Cowley4,2, and J. C. McWilliams6
1DAMTP, University of Cambridge, Cambridge CB3 0WA, United Kingdom
2Plasma Physics Group, Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom
3Department of Mechanical Engineering, The Ben-Gurion University of the Negev, P. O. Box 653, Beer-Sheva 84105, Israel
4Department of Physics and Astronomy, UCLA, Los Angeles, California 90095-1547, USA
5Wolfgang Pauli Institute, University of Vienna, Nordbergstraße 15, A-1090 Vienna, Austria
6Department of Atmospheric Sciences, UCLA, Los Angeles, California 90095-1565, USA

Received 17 October 2007; published 6 May 2008

The feasibility of a mean-field dynamo in nonhelical turbulence with a superimposed linear shear is studied numerically in elongated shearing boxes. Exponential growth of the magnetic field at scales much larger than the outer scale of the turbulence is found. The characteristic scale of the field is lB̅ ∝S-1/2 and the growth rate is γ∝S, where S is the shearing rate. This newly discovered shear dynamo effect potentially represents a very generic mechanism for generating large-scale magnetic fields in a broad class of astrophysical systems with spatially coherent mean flows.

© 2008 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevLett.100.184501
DOI:
10.1103/PhysRevLett.100.184501
PACS:
47.27.W−, 47.65.Md, 95.30.Qd, 98.62.En
 
< Previous Article | Next Article >