The rotation of the Sun

Abstract

Observations of solar rotation are reviewed. There are two basic methods of determining the rotation of the sun. One is to measure the daily or monthly positions of tracers on the surface or in the corona, and the other is to measure line‐of‐sight velocities with the Doppler effect in spectrum lines. The results of a number of investigations involving both methods are compared. The experimental and interpretational problems associated with observational determinations of solar rotation are reviewed and compared. The theoretical situation in this field is reviewed, including the significance of different rotation rates for surface magnetic features and the solar plasma. The rotation of the solar interior is discussed in terms of both model calculations and recent p mode oscillation rotation rates, which reflect the interior rotation.

Surface Evolution of the Sun's Magnetic Field: A Historical Review of the Flux-Transport Mechanism

“…The quasi-rigid rotations of photospheric fields were thought to indicate rotational properties of the subsurface layers in which they were rooted (Stenflo, 1974(Stenflo, , 1977Snodgrass, 1983). Rigid rotations of coronal holes and other coronal structures were interpreted as fundamental manifestations of rigidly rotating subsurface fields (Zirker, 1977;Howard, 1978Howard, , 1984. Solar physics had truly entered the 'dark ages' of understanding.…”

Solar rotation studies using sunspot data (1967?1974)

“…Error bars are standard deviations of the means; note that there may be additional systematic errors in the Mt. Wilson data, as described in Howard and Harvey (1970). The solar rotation rate has also been measured since 1967 using Ha and Ca K plages as identifiable tracers (Belvedere et al, 1978).…”

“…The assumption of a fixed rotation law introduces the possibility of errors due to real, short-term variations in the solar differential rotation. However, such variations, if similar to those determined from spectroscopic data (Howard, 1976;Livingston and Duvall, 1979) are small for latitudes less than 30 deg and would not significantly affect the sunspot rates.…”

“…Recently many questions have been raised regarding the solar rotation rate, particularly the existence of possible variations on time scales less than one year as well as long-term trends (Howard and Harvey, 1970;Howard, 1976;Schr6ter and W6hl, 1978;Belvedere etal., 1978;Livingston and Duvall, 1979), There has also been new interest in the approximately five percent faster rotation rate measured from various magnetic tracers as compared with spectroscopic measurements (see reviews by Gilman, 1974;and Howard, 1978). The solar rotation measurements of the present study were prompted by the fact that the most often quoted sunspot rotation measurements (Newton and Nunn, 1951;Ward, 1966) do not coincide in time with the recent spectroscopic data which show the year-to-year variations and long-term trends.…”

Free oscillations of the sun and the giant planets

“…Такое возрастание скорости примерно на 80 м/с к глуби-нам около 11-15 тыс. км согласуется в пределах ошибки измерения с наблюдаемой разницей в периодах вращения солнечных пятен и фото-сферной плазмы (современные результаты исследований вращения Солнца содержатся в обзоре Ховарда 70 ). Ниже уровня 15 тыс.…”