A sample of 32 flare events are analyzed to evaluate how these events agree with a flare-triggering model, which examines shear angles of large-scale magnetic field and small-scale dipole field during the flares’ precursor brightening.
A set of parameters that characterize the complexity and energy potential of solar active-regions is fed through several Machine Learning and conventional statistics algorithms to forecast solar flares.
A deep-learning method, Convolutional Neural Network, is developed to use the HMI’s line-of-sight magnetic field to forecast solar flares.
Where does a sunspot’s penumbra start to form, on the same side or the opposite side of its opposite-polarity sunspot? When does Evershed flow start to appear, before or after the penumbral formation? These questions are answered through analyzing selected samples observed by the HMI.
The majority of flare forecasting methods rely on observations of magnetic field on the Sun’s surface, but which observable, Br or Blos, is a better predictor? Through comparing a few magnetic properties derived from both observables, this nugget gives some suggestion.
It is demonstrated that when taking into account of the radial inhomogeneity of the Coriolis number, the solar-like differential rotation and the double-cell meridional circulation can both be reproduced by the mean-field model.
AR12192, the largest active region in Solar Cycle 24, produced 6 X-class flares, but none of them were associated with a CME. However, a much weaker flare, of M4.0-class, was associated with a CME. Magnetic field and morphological changes are analyzed during these flares to understand why this is the case.
Various observable, such as polar field, meridional flow, and sunspot number, are examined to identify information flow, causality, and time delay between them during solar cycles. It is expected that this analysis can provide observational constraints on solar cycle models and theories.
44 strong flares are analyzed, and a few factors are identified to determine whether a flare will be eruptive or confined.
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.