Author ORCID Identifier

James McAteer:
https://orcid.org/0000-0003-1493-101X

Document Type

Journal Article

Journal Article Version

Final Version / Publisher's PDF (peer-reviewed)

Publication Date

12-1-2014

Abstract

Chromospheric flare ribbons observed in H alpha appear well-organized when first examined: ribbons impulsively brighten, morphologically evolve, and exponentially decay back to pre-flare levels. Upon closer inspection of the H alpha flares, there is often a significant number of compact areas brightening in concert with the flare eruption but are spatially separated from the evolving flare ribbon. One class of these brightenings is known as sequential chromospheric brightenings (SCBs). SCBs are often observed in the immediate vicinity of erupting flares and are associated with coronal mass ejections. In the past decade there have been several previous investigations of SCBs. These studies have exclusively relied upon H alpha images to discover and analyze these ephemeral brightenings. This work employs the automated detection algorithm of Kirk et al. to extract the physical qualities of SCBs in observations of ground-based H alpha images and complementary Atmospheric Imaging Assembly images in He II, C IV, and 1700 angstrom. The metadata produced in this tracking process are then culled using complementary Doppler velocities to isolate three distinguishable types of SCBs. From a statistical analysis, we find that the SCBs at the chromospheric H alpha layer appear earlier and last longer than their corresponding signatures measured in AIA. From this multi-layer analysis, we infer that SCBs are spatially constrained to the mid-chromosphere. We also derive an energy budget to explain SCBs which have a postulated energy of not more than 0.01% of the total flare energy.

Published in

Astrophysical Journal

DOI

10.1088/0004-637X/796/2/78

Keywords

Sun: flares, Sun: coronal mass ejections (CMEs), Sun: chromosphere

Department / Organizational Unit

Astronomy

License for Reuse

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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