Thermodynamic Evolution of Solar Flare Supra-arcade Downflows

Solar flares are rapid energy release phenomena that appear as bright ribbons in the chromosphere and high-temperature loops corona, respectively. Supra-arcade Downflows (SADs) plasma voids first come out above flare then move quickly towards loop top during decay phase of flare. In our work, we study 20 SADs appearing three flares. By differential emission measure (DEM) analysis, calculate DEM weighted average temperature (EM) front region main body SADs. It is found temperatures SAD tend to increase course flowing downwards. The relationship between pressure fits well with adiabatic equation for both body, suggesting heating mainly caused by compression. Moreover, also estimate velocities via Fourier Local Correlation Tracking (FLCT) method find presents a correlation decrease kinetic energy, while does not, implying viscous process may heat spite limited role.