Abstract:
For sunspot groups occuring in latitude bin 10 degree - 20 degree and living 10-12 days, we find that the mean variation, ω(t) of the rotation frequency with age, has the same trend as the radial variation, Ω(r), of the rotation frequency of the solar plasma across the convective envelope in the same latitude bin. For spot groups in given latitude intervals, which live for 2-12 days, the mean variation of the initial rotation frequency, ωini (τ), of a spot group, with respect to its life span, τ, also has a trend similar to that of ω (τ). We have estimated depths of origin and rate of emergence of the magnetic structures of spot groups in latitudes 10 degree - 15 degree