On the dependence of the linear velocity of solar rotation on latitude and optical depth

Abstract

The law of solar axial rotation is investigated by the spectroscopic method. Fayes formula: υ(ϕ) = 2.03 − 1.6 sin^ϕ followed from a great number of observations (800 different values of velocity derived from an investigation of 800 spectral lines of different intensity and of different elements). The dependence of the solar rotation on the depth in the atmosphere was investigated. For this purpose the optical depths of the formation of the core of 800 spectral lines were determined. The dependence of the rotational velocity on the heliographic latitude and the depth in the atmosphere is well described by the empirical formula (Equation (5) in the text).

The main conclusion of this investigation is the existence of an anomaly in the rotational velocity of the Sun at heliographic latitude 25°. Moreover the amplitude of the deflexion of the rotational velocity at the above-mentioned latitude varies with the optical depth.