Category Archives: Magnetic Field

84. Abrupt and Permanent Changes of the Photospheric Magnetic Field During 75 flares observed with HMI

Contributed by Sebastián Castellanos Durán. Posted on January 16, 2018

Magnetic field changes associated with solar flares, observed by the SDO/HMI, are surveyed, and permanent changes of magnetic field are found in the majority of flare events. Properties of the magnetic field changes are further investigated.

79. Homologous Circular-Ribbon Flares Driven by Twisted Flux Emergence

Contributed by Zhi Xu. Posted on December 18, 2017

Two homologous circular-ribbon flares associated with two filament eruptions were observed and analyzed. The emergence of magnetic flux ropes helped to inject free energy into the region and drive the magnetic reconnection above it.

70. Magnetic Flux Emergence & Decay Rates for Sunspots Observed with HMI

Contributed by Aimee Norton. Posted on May 23, 2017

We quantify the emergence and decay rates of ten bipolar active regions using vector magnetic field data from HMI. Our results, placed in context with other observational and modeling results in the literature, confirm a trend that higher flux regions emerge faster and the rate is dependent on the total flux of that region.