Persistent magnetic flux emergence with perpendicular separation directions in AR 13842 rapidly formed a collisional shearing PIL, with frequent flux cancellations there, leading to repeated magnetic flux rope formations and multiple large flares. The pre-flare decreases in the sheared PIL’ s area and free-energy density may serve as a promising precursor for major eruptive flares.
Using SDO/HMI white-light continuum observations and GOES Lyα and SXR irradiance, this study investigates 69 solar white-light flares to examine their emission properties, including enhancement, peak-time ordering, evolutionary timescales, and relationships between the emission parameters and radiated energy.
Magnetofrictional simulations of Active Region 13500 reproduce its transition from stability to eruption and show that a massive sigmoid flux rope formed during the decay phase. The eruption began when the current-carrying helicity ratio reached about 0.3, indicating that helicity-based markers can help diagnose the eruptive potential of active regions.
Through MHD simulations of flux eruptions, the study finds that the current helicity decreases prior to eruptions and then reverses to increase afterward. By examining multiple flare events, the authors identified observational evidence supporting these simulation results.
Multiple X-class flares and CMEs were produced by AR 13664/8 during the Mother’s Day week of 2024. This study suggests that predicting the locations of magnetically complex active regions, and studying and tracking their eruptive states using different proxy parameters can greatly improve the capability to forecast intense storms.
Eruptive and non-eruptive solar flares were investigated based on an analysis of electric current neutralization and torus instability. Combined analysis of these factors offers a more reliable prediction of eruptive events than relying on either one alone.
The analysis of magnetic fields and electrical currents indicates that a specific configuration – currents in opposite magnetic regions flowing in the same direction and peaking concurrently – might create favorable conditions for the magnetic reconnection process that powers solar flares.
Moreton waves were studied using a systematic survey of Moreton-wave events observed during the SDO era. The results showed that inclined magnetic configurations act as a wall, forcing eruptions and Moreton waves to propagate toward weaker magnetic fields.
A few major geoeffective flares and CMEs occurred in May 2024. HMI magnetic field data were used to examine how the flares occurred and why they became geoeffective.
The coronal magnetic field evolution of the AR 11429 was simulated using time-dependent magneto-friction model. The model reproduced the magnetic structure that has remarkable correspondence with the spatial characteristics in coronal extreme ultraviolet images.