May 24 – 26, 2021
Virtual
US/Eastern timezone

Connecting chromospheric condensation signatures to reconnection driven heating rates in an X1.0 flare

May 26, 2021, 1:00 PM
40m
Virtual

Virtual

Poster Flare and Nanoflare heating Poster session: SQ3 and SQ6

Speaker

William Ashfield (Montana State University)

Description

Observations of solar flare reconnection at very high resolution can be indirectly made at the footpoints of reconnected loops into which flare energy is deposited. The response of the lower atmosphere to this energy input includes a downward-propagating shock called chromospheric condensation, which can be observed at wavelengths including UV and visible. In order to characterize reconnection using high resolution observations of this shock, one must develop a quantitative relationship between the two. Such a relation was recently developed in previous work and here we test it on observations of chromospheric condensation in a single footpoint in the flare ribbon of the X1.0 flare SOL2014-10-25T16:56:36. Measurements taken of Si\,\textsc{iv}\,1402.77\,\AA\ emission spectra with the Interface Region Imaging Spectrograph (IRIS) using a 5\,s cadence show a red-shifted component undergoing typical condensation evolution, with a peak downward velocity of 35\,km\,s$^{-1}$ and a half-life of 16\,s. Simultaneous observations taken with the Atmospheric Imaging Assembly (AIA) reveal a temporally and spatially correlated increase in UV emission in the 1600\,\AA\ band. We apply a technique called the Ultraviolet Footpoint Calorimeter (UFC) to the 1600\,\AA\ lightcurve to infer the energy deposition into the footpoint. We then input this energy into a one-dimensional, hydrodynamic simulation to compute the chromospheric response, including condensation. From this simulation we synthesize Si\,\textsc{iv} spectra and compute the time-evolving Doppler velocity. This is found to compare reasonably well with the IRIS observation, thus corroborating our reconnection-condensation relationship.

Primary authors

William Ashfield (Montana State University) Prof. Dana Longcope (Montana State University) Dr Chunming Zhu (Montana State University ) Dr Jiong Qiu (Montana State University)

Presentation materials