Please use this identifier to cite or link to this item: http://hdl.handle.net/2248/6797
Title: Is a Deep One-cell Meridional Circulation Essential for the Flux Transport Solar Dynamo?
Authors: Hazra, G
Karak, B. B
Choudhuri, A. R
Keywords: Dynamo
Sun: activity
Sun: magnetic fields
Issue Date: 20-Feb-2014
Publisher: IOP Publishing
Citation: The Astrophysical Journal, Vol. 782, No. 2, 93
Abstract: The solar activity cycle is successfully modeled by the flux transport dynamo, in which the meridional circulation of the Sun plays an important role. Most of the kinematic dynamo simulations assume a one-cell structure of the meridional circulation within the convection zone, with the equatorward return flow at its bottom. In view of the recent claims that the return flow occurs at a much shallower depth, we explore whether a meridional circulation with such a shallow return flow can still retain the attractive features of the flux transport dynamo (such as a proper butterfly diagram, the proper phase relation between the toroidal and poloidal fields). We consider additional cells of the meridional circulation below the shallow return flow—both the case of multiple cells radially stacked above one another and the case of more complicated cell patterns. As long as there is an equatorward flow in low latitudes at the bottom of the convection zone, we find that the solar behavior is approximately reproduced. However, if there is either no flow or a poleward flow at the bottom of the convection zone, then we cannot reproduce solar behavior. On making the turbulent diffusivity low, we still find periodic behavior, although the period of the cycle becomes unrealistically large. In addition, with a low diffusivity, we do not get the observed correlation between the polar field at the sunspot minimum and the strength of the next cycle, which is reproduced when diffusivity is high. On introducing radially downward pumping, we get a more reasonable period and more solar-like behavior even with low diffusivity.
Description: Restricted Access
URI: http://prints.iiap.res.in/handle/2248/6797
ISSN: 0004-637X
Appears in Collections:IIAP Publications

Files in This Item:
File Description SizeFormat 
IS A DEEP ONE-CELL MERIDIONAL CIRCULATION.pdf4.36 MBAdobe PDFThumbnail
View/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.