Solar active region evolution and imminent flaring activity through a color-coded visualization of photospheric vector magnetograms

Abstract

The emergence of magnetic flux, its transition to complex configurations, and the pre-eruptive state of active regions are probed using photospheric magnetograms. We aim to pinpoint different evolutionary stages in active regions, explore their differences and produce parameters that could advance flare prediction, using color-coded maps of the photospheric magnetic field. The three components of the photospheric magnetic field vector are combined in color-coded magnetograms (COCOMAGs). From these, the areas occupied by different colors are extracted, creating appropriate time series (color curves). The COCOMAGs and color curves are used as proxies of the active region evolution and complexity. The COCOMAGs morphology reflects typical features of active regions, such as sunspots, plages, and sheared polarity inversion lines. The color curves represent the area occupied by photospheric magnetic field of different orientation and contain information relevant to the evolutionary stages of active regions. During emergence, most of the area is dominated by horizontal or highly inclined magnetic field, which gradually gives its place to more vertical magnetic field. In complex regions, large parts are covered by highly inclined magnetic fields, appearing as abrupt color changes. Active region decay is signified by a domination of vertical magnetic field, indicating a gradual relaxation of the magnetic field configuration. The color curves exhibit varying degree of correlation with active region complexity. The red and magenta color curves, which represent strong, purely horizontal magnetic field, are good indicators of future flaring. Color-coded magnetograms facilitate a comprehensive view of the evolution of active regions and their complexity. They offer a framework for the treatment of complex observations and can be used in pattern recognition, feature extraction and flare prediction.

10 pages, 8 figures, to be published in Astronomy & Astrophysics

References in corpus (15)

• The Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Pipeline: SHARPs -- Space-weather HMI Active Region Patches
• The Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Pipeline: Overview and Performance
• Why Is the Great Solar Active Region 12192 Flare-Rich But CME-Poor?
• Magnetic Properties of Solar Active Regions that Govern Large Solar Flares and Eruptions
• Magnetic Twist and Writhe of Active Regions: On the Origin of Deformed Flux Tubes
• A comparative study of two X2.2 and X9.3 solar flares observed with HARPS-N: Reconciling Sun-as-a-star spectroscopy and high-spatial resolution solar observations in the context of the solar-stellar connection
• The characteristics of flare- and CME-productive solar active regions
• Flare Kernels May be Smaller than You Think: Modelling the Radiative Response of Chromospheric Plasma Adjacent to a Solar Flare
• Combining magneto-hydrostatic constraints with Stokes profile inversions. II. Application to Hinode/SP observations
• Three-dimensional magnetic field structure of a flux emerging region in the solar atmosphere
• Spectral variations within solar flare ribbons
• Emergence of small-scale magnetic flux in the quiet Sun
• Classification of High-resolution Solar Hα Spectra using t-distributed Stochastic Neighbor Embedding
• Shape-based clustering of synthetic Stokes profiles using k-means and k-Shape
• Background-subtracted Solar Activity Maps

Cited by in corpus (2)

• Average solar active region: I. Intensities, velocities, and the photospheric magnetic field
• Statistical Analysis of Minifilament Eruptions Using Full-disk H$\alpha$ Blue-wing Observations at Big Bear Solar Observatory