Morphology of solar flares from observations in the lower atmosphere
Chromospheric Dynamics
Anne-Marie
Broomhall
Date Submitted
2021-04-30 00:00:00
University of Warwick
Anne-Marie Broomhall, Larisa K. Kashapova, Alena I. Larionova, Elena G. Kupriyanova, and Ilya D. Motyk
We present an analysis of the shape of the decay phase of solar flares as seen in Sun-as-a-star SDO/AIA data. It was inspired by the study of white light flares on an M4 dwarf, presented by Davenport et al. (2014). We limited our study to the solar flare with a classical shape of decay phase consisting of a slow, continuous and smooth decay phase observed in 304, 1600 and 1700 Angstroms. We limited our study to those with a classical flare shape consisting of a slow, continuous and smooth decay phase observed in 304, 1600 and 1700 Angstroms. This left us with a sample of over 100 flares in 304 and 1600 Angstroms, and 53 flares in 1700 Angstrom data. The amplitudes and timescales of these flares were normalized, allowing us to construct average flare profiles for each channel, which were fitted with analytical templates. As was found for the M dwarf, the decay profiles were best described by a model containing two exponents. However, the time ranges used to best fit the data were different from those found for the M dwarf. We speculate that this was because of the impact of chromospheric plasma evaporation. We also found that the average solar flare profiles decayed more slowly than the average profile of the M dwarf flares, which potentially indicates that the M dwarf white light emission comes from a higher density layer than the solar emission considered here.
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