Same as Fig. 2 but taking into account a Doppler shift correction because observations were performed in the Carrington frame of reference as well as tachocline differential rotation, with differential rotation parameters taken for the middle of the tachocline layer; namely, the rotation period at 30° latitude of 26.5 days, and a rotation period at 15° latitude of 26.1 days. (a) Dispersion relations (0kG). (b) Dispersion relations (5kG). (c) Dispersion relations (15kG). (d) Dispersion relations (30kG).