A new upper limit to the temporal variation of the rotation rate of the tachocline between 1994 and 2002

Eff-Darwich, A.; Korzennik, S. G.
Bibliographical reference

In: Proceedings of SOHO 12 / GONG+ 2002. Local and global helioseismology: the present and future, 27 October - 1 November 2002, Big Bear Lake, CA, USA. Edited by H. Sawaya-Lacoste, ESA SP-517, Noordwijk, Netherlands: ESA Publications Division, ISBN 92-9092-827-1, 2003, p. 267 - 270

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2
2003
Number of authors
2
IAC number of authors
0
Citations
1
Refereed citations
1
Description
We have inverted most of the available rotational frequency splittings at intermediate degrees. Namely, LOWL data from 1994 to 2000, GONG data from 1995 to 2001, and, MDI data from 1996 to 2002. Our purpose was to look for any temporal variation of the tachocline and its relation to the solar activity cycle. However, we did not find any significant change compatible with the three data sets. From our analysis, we estimated an upper limit on the temporal variation of Ω/2π of 3 nHz. This value is commensurable with the sensitivity of the present observational data to changes in the rotation rate of the tachocline.