Tilt Angles of Sunspot Groups in Different Latitude Bands and the Amplitude of the Next Solar Cycle

Abstract In the Babcock–Leighton and Parker dynamo models, the tilt angle of a sunspot group (SG) and the turbulence in the solar convection zone (one widely accepted generation mechanism responsible for the scatter of the tilt angles of SGs around the mean), respectively, are thought to represent the source of the poloidal field, which serves as the seed field for the toroidal field forming SGs during the next solar cycle (SC). We analyse the sunspot data from the Kodaikanal observatory to investigate the relationships of the mean tilt angles and the tilt-angle scatters (the standard deviations of the tilt angles) in different latitude bands with the amplitude of the next/same SC. The two main findings of our analysis are as follows. (1) The mean tilt angle at low latitudes (≤10 ∘ ) has a significant positive correlation with the amplitude of the next SC; however, the mean tilt angle at high latitudes (>20 ∘ ) shows a significant anticorrelation with the amplitude of the next SC. (2) The tilt-angle scatter at low latitudes exhibits a significant anticorrelation with the amplitude of the next SC, while the tilt-angle scatter at high latitudes has a significant positive correlation with the amplitude of the same SC. These findings suggest that the tilt angles of SGs in different latitude bands play different roles in regulating SC variability.