88. On the Factors Determining the Eruptive Character of Solar Flares
44 strong flares are analyzed, and a few factors are identified to determine whether a flare will be eruptive or confined.
Category Archives: Magnetic Field
87. Magnetic Reconnection at the Earliest Stage of Solar Flux Emergence
The early phase of a flux emergence was observed by IRIS, and spectra of the accompanying UV bursts are analyzed. Many bursts appear to be associated with the magnetic flux cancellation, and almost all of them are located in regions with large squashing factors.
85. A Statistical Comparison between Photospheric Vector Magnetograms Obtained by SDO/HMI and Hinode/SP
Vector magnetic fields, obtained separately from the HMI and from the Stokes parameters of Hinode, are compared for a sunspot umbra, penumbra, and plages in a selected active region.
84. Abrupt and Permanent Changes of the Photospheric Magnetic Field During 75 flares observed with HMI
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.
83. Observing and modeling the poloidal and toroidal fields of the solar dynamo
The Sun’s surface poloidal and toroidal magnetic field were constructed for the last 4 solar cycles using observations from multiple instruments, and were then reproduced using the updated Babcock-Leighton model.
82. A Super-Synoptic Map of HMI Flux Density
Super-synoptic map is constructed using SDO/HMI’s synoptic magnetic maps of each Carrington rotation, covering the period of May 2010 to December 2017. Polarity reversals can be clearly seen in the map.
81. The Dipole, Quadrupole, and Octupole Components of the Solar Magnetic Field Over 22 Years
The dipole, quadrupole, and octupole components of the Sun’s magnetic field are calculated and visualized, covering the last 22 years of the Sun’s activities.
79. Homologous Circular-Ribbon Flares Driven by Twisted Flux Emergence
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.
71. Critical Height of the Torus Instability in Two-Ribbon Solar Flares
A statistical investigation of the background magnetic field decay index reveals interesting features of the critical height for the flux rope torus instability.
70. Magnetic Flux Emergence & Decay Rates for Sunspots Observed with HMI
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.