On variation of the latitudinal structure of the solar convection zone

Antia, H. M. ; Chitre, S. M. ; Thompson, M. J. (2003) On variation of the latitudinal structure of the solar convection zone Astronomy & Astrophysics, 399 (1). pp. 329-336. ISSN 0004-6361

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Official URL: http://www.aanda.org/articles/aa/abs/2003/07/aa312...

Related URL: http://dx.doi.org/10.1051/0004-6361:20021760


The latitudinal sound-speed structure of the Sun's convection zone gives insight into the physical processes occurring there, specifically the cellular convection and possibly the presence of magnetic fields. Using helioseismic data from the GONG network and MDI instrument on SOHO, we map the latitudinal acoustic structure of the convection zone from 1995 to 2002. The temporally averaged structure confirms previous findings of an excess in sound speed at the 10-4 level at 60 degrees latitude. There also appear to be some variation with time, with the peak in sound-speed asphericity at 60 degrees growing towards the maximum of solar activity according to the MDI data. However, we present some evidence that such variation may be associated with instrumental variation between the epochs before and after SOHO was temporarily lost in 1998. Nonetheless, some genuine temporal variation may be present, and we discuss the possible physical causes of that.

Item Type:Article
Source:Copyright of this article belongs to European Southern Observatory.
Keywords:Sun: Oscillations; Sun: Interior; Sun: Rotation; Sun: Activity; Methods: Data Analysis
ID Code:5791
Deposited On:19 Oct 2010 10:56
Last Modified:16 May 2016 16:14

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