Category Archives: Magnetic Field

211. Electric Current Neutralization and Critical Height of Flux Rope in Eruptive and Non-Eruptive Active Regions

Contributed by Johan Muhamad. Posted on May 12, 2025

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.

210. The Role of Electric Currents in the October 2014 X1.6 Solar Flare

Contributed by Partha Chowdhury. Posted on April 28, 2025

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.

209. The Magnetic Origin of Chromospheric Moreton Waves

Contributed by Ze Zhong. Posted on March 21, 2025

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.

207. Simulating the formation and eruption of magnetic flux ropes in the solar atmosphere

Contributed by P. Vemareddy. Posted on January 8, 2025

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.

206. Magnetic power spectra of the Sun and cycle dependence of magnetic network

Contributed by Yukun Luo. Posted on January 7, 2025

Magnetic power spectra were calculated using MDI and HMI data for two solar cycles. It is found that the sizes of the magnetic networks do not show a cycle dependence, but the power-law indices estimated from the active region and network sizes show an anti-correlation with the sunspot numbers.

201. Study of Bipolar Magnetic Regions using AutoTAB: Support of Thin Flux Tube Model?

Contributed by Bidya Karak. Posted on July 4, 2024

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.

195. Cross-Referenced NOAA Active Region List for Multi-Rotation Active Regions, 2011-2019 Now Available

Contributed by Emily Mason. Posted on September 22, 2023

It is well known that many active regions (ARs) last longer than one solar rotation, however, they are often assigned one NOAA AR number for each rotation. This work lists most, if not all, of the ARs that are a same AR but with different AR numbers.

194. Rossby waves and the organization of photospheric magnetic fields

Contributed by Breno Raphaldini. Posted on September 20, 2023

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.