On the possibility of an alpha-sq omega-type dynamo in a thin layer inside the sun

Choudhuri, Arnab Rai (1990) On the possibility of an alpha-sq omega-type dynamo in a thin layer inside the sun. In: Astrophysical Journal, The, 355 (2). pp. 733-744.

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Abstract

If the solar dynamo operates in a thin layer of 10,000-km thickness at the interface between the convection zone and the radiative core, using the facts that the dynamo should have a period of 22 years and a half-wavelength of 40 deg in the theta-direction, it is possible to impose restrictions on the values which various dynamo parameters are allowed to have. It is pointed out that the dynamo should be of alpha-sq omega nature, and kinematical calculations are presented for free dynamo waves and for dynamos in thin rectangular slabs with appropriate boundary conditions. An alpha-sq omega dynamo is expected to produce a significant poloidal field which does not leak to the solar surface. It is found that the turbulent diffusity eta and alpha-coefficient are restricted to values within about a factor of 10, the median values being eta of about 10 to the 10th sq cm/sec and alpha of about 10 cm/sec. On the basis of mixing length theory, it is pointed out that such values imply a reasonable turbulent velocity of the order 30 m/s, but rather small turbulent length scales like 300 km.

Item Type:	Journal Article
Publication:	Astrophysical Journal, The
Publisher:	University of Chicago Press
Additional Information:	Copyright of this article belongs to University of Chicago Press.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	27 Apr 2011 06:10
Last Modified:	27 Apr 2011 06:10
URI:	http://eprints.iisc.ac.in/id/eprint/34996

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