This study analyzes a few properties of evolving bipolar magnetic regions: separation of polarities, tilt angles, and tilt angle and flux relations. The analysis supports that the bipolar regions form from thin-flux tubes and Coriolis force plays an important role in forming the regions.
The advective flux transport model, coupled with a random active region generator, predicts that the solar activity will peak in the northern hemisphere around August 2024, and peak in the southern hemisphere around February 2025.
Equatorial Rossby waves are detected using the HMI’s time-distance subsurface flow fields. It is also found that the power of the Rossby waves show a positive correlation with the sunspot number, while the frequency of the waves shows an anti-correlation with the sunspot number.
HMI magnetic field synoptic maps are used to evaluate the magnetic field structures’ organization and propagation as a function of time and latitude. It is demonstrated that the organization of longitudinal structures observed on synoptic maps is proportional to the level of activity at given latitudes.
This study reveals correlations between the motion of pores and the maximum magnetic pressure difference at their opposite edges, but no causal relationship between the two is found.
The CGEM team identified and corrected two artifacts that had affected the electric field calculation for a small number of active regions.
Twelve years of HMI Dopplergram and magnetogram data have been used to uncover the solar cycle dependence of the magnetically quietest regions on the Sun and to reveal an enigmatic behavior of the surface-gravity wave energy contained in those regions.
This study reveals that a significant number of coronal-hole field lines extend beyond the coronal-hole boundaries and that many coronal-holes contain no open magnetic field lines.
Inverse Evershed flow is derived from chromospheric observations. Coupling these flow with the non force-free model, the authors find that the flow is driven along magnetic field lines connecting network elements with the outer penumbra by a gas pressure difference.
Briefly shown here are some results from a new global coronal MHD simulation model, with a new method to use the three-component vector HMI synoptic maps as time-dependent boundary values.