
Solar internal rotation rate and the latitudinal variation of the tachocline
Author(s) -
Antia H. M.,
Basu Sarbani,
Chitre S. M.
Publication year - 1998
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1998.01635.x
Subject(s) - tachocline , physics , convection zone , differential rotation , solar rotation , helioseismology , radiation zone , astrophysics , latitude , rotation (mathematics) , radiative transfer , internal rotation , computational physics , geodesy , geometry , solar physics , optics , astronomy , magnetic field , geology , stars , mechanical engineering , mathematics , engineering , quantum mechanics
A new set of accurately measured frequencies of solar oscillations is used to infer the rotation rate inside the Sun, as a function of radial distance as well as latitude. We have adopted a regularized least‐squares technique with iterative refinement for both 1.5D inversion, using the splitting coefficients, and 2D inversion using individual m splittings. The inferred rotation rate agrees well with earlier estimates showing a shear layer just below the surface and another one around the base of the convection zone. The tachocline or the transition layer where the rotation rate changes from differential rotation in the convection zone to an almost latitudinally independent rotation rate in the radiative interior is studied in detail. No compelling evidence for any latitudinal variation in the position and width of the tachocline is found, although it appears that the tachocline probably shifts to a slightly larger radial distance at higher latitudes and possibly also becomes thicker. However, these variations are within the estimated errors and more accurate data would be needed to make a definitive statement about latitudinal variations.