The chromospheric line-of-sight velocity variations in a solar microflare

The spectropolarimetric observations were carried out with the French-Italian THEMIS telescope (Spain, Tenerife). We used Hα spectra of the high resolution obtained over 21 min. The spatial resolution was ∼1 arcsec. The time interval between the spectra was 2.84 s. Doppler velocities were measured in the microflare location and its surroundings. We have revealed strong temporal variations of the line-of-sight velocity in the chromosphere. The velocities changed in the range −33-10 km/s. We revealed the velocity oscillations with the amplitude of 4-5 km/s. 12-14 min before the microflare both upward and downward motions with velocity values reaching about 20 km/s are found on the outer edge of the region studied. The amplitude of the oscillations increased. It may be the signature of the magnetic reconnection.