A neural network has been developed and applied on helioseismic far-side images, and substantially improved the number of far-side active region detections with higher true positive rate.
Magnetic-field dependence of active regions’ tilt angles are analyzed using the MDI and HMI observations for two solar cycles. The variation of the tilt angles with the maximum magnetic-field strength of the ARs indicates a nonlinear tilt quenching in the Babcock–Leighton process.
Similar to sunspots, the stable regions of pores on the Sun are also found to be defined by a critical value of the vertical component of the magnetic field. The critical value is comparable to that found in stable sunspots.