Plasma motions in the solar loop of the emerging magnetic flux

1Pasechnik, MN
1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
Section: Solar Physics
Language: Russian

We present some results of our analysis of plasma line-of-sight velocity changes in the solar loop at the chromospheric and photospheric levels in the emerging magnetic flux area in developing active region NOAA 11024. Our analysis combines multiwavelength spectropolarimetric observations carried out on 4 July 2009 with the solar telescope THEMIS (the island of Tenerife, Spain), and data from the space satellites GOES, SOHO, STEREO. It is possible to understand the complex sequence of events associated with the new magnetic flux emergence and Ellerman bomb, microflare GOES class B1 and four chromospheric surges formation there were a result of magnetic reconnection. Ellerman bomb developed in the vicinity of a growing pore. The velocity oscillations there were in the chromosphere and photosphere in its area. Before microflare average VLOS plasma of the upward and downward flows in the leg of the magnetic loop was about 26 km/s. These flows were associated with a twisting motion of the loop. During microflare upflowing velocities increased to –33 km/s, and the VLOS downflow up to 50 km/s. Velocity changes of matter motion in the second leg of the magnetic loop well correlated with microflare VLOS changes, but occurred 1.5 minutes later. Four chromospheric surges formed during our observations, three of them in the area of the Ellerman bomb development. Sharp changes in the soft X-ray intensity there were at that time. At the photospheric level during microflare velocity variations in the loop legs were opposite — in the area of one leg VLOS decreased from –1.8 km/s to –0.4 km/s, and in the second leg VLOS increased from –0.6 km/s to –2.6 km/s.

Keywords: chromosphere, photosphere, plasma, solar loop