id:"swepub:oai:DiVA.org:su-70036"
Search: id:"swepub:oai:DiVA.org:su-70036" > Alpha effect due to...
- 1 of 1
- Previous record
- Next record
- To hitlist
Alpha effect due to buoyancy instability of a magnetic layer
- Chatterjee, P. (author)
- Mitra, D. (author)
- Rheinhardt, M. (author)
- show more...
- show less...
- (creator_code:org_t)
- 2011-09-30
- 2011
- English.
- In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 534, s. A 46-
- Journal article (peer-reviewed)
Abstract
Subject headings
Close
- Context. A strong toroidal field can exist in form of a magnetic layer in the overshoot region below the solar convection zone. This motivates a more detailed study of the magnetic buoyancy instability with rotation. Aims: We calculate the α effect due to helical motions caused by an unstable magnetic layer in a rotating density-stratified system with angular velocity Ω making an angle θ with the vertical. We also study the dependence of the α effect on θ and the strength of the initial magnetic field. Methods: We carry out three-dimensional hydromagnetic simulations in Cartesian geometry. A turbulent electromotive force (EMF) due to the correlations of the small scale velocity and magnetic field is generated. We use the test-field method to calculate the transport coefficients of the inhomogeneous turbulence produced by the layer. Results: We show that the growth rate of the instability and the twist of the magnetic field vary monotonically with the ratio of thermal conductivity to magnetic diffusivity. The resulting α effect is non-uniform and increases with the strength of the initial magnetic field. It is thus an example of an "anti-quenched" α effect. The α effect is also nonlocal, i.e. scale dependent, requiring around 8-16 Fourier modes to reconstruct the actual mean EMF based on the actual mean field.
Subject headings
- NATURVETENSKAP -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)
Keyword
- magnetohydrodynamics (MHD)
- magnetic fields
- turbulence
- dynamo
- instabilities
Publication and Content Type
- ref (subject category)
- art (subject category)
Find in a library
- Astronomy and Astrophysics (Search for host publication in LIBRIS)
To the university's database
- 1 of 1
- Previous record
- Next record
- To hitlist
Find more in SwePub
- By the author/editor
- Chatterjee, P.
- Mitra, D.
- Rheinhardt, M.
- Brandenburg, Axe ...
- About the subject
-
- NATURAL SCIENCES
- NATURAL SCIENCES
- and Physical Science ...
- and Astronomy Astrop ...
- Articles in the publication
- Astronomy and As ...
- By the university
- Stockholm University
Search outside SwePub
- Extend your search to:
- Google Book Search
- Google Scholar
Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.
- Copyright © LIBRIS - National Library Systems
- LIBRIS.kb.se
