SOLAR PLASMA DYNAMICS DURING THE FORMATION AND DEVELOPMENT OF ELLERMAN BOMBS PAIR

Анотація

The results of the specific features
study of solar plasma dynamics in different layers of
the active region (AR) of NOAA 11024 under the in-
fluence arisen and evolving two Ellerman bombs (EB-1
and EB-2) are presented. Spectral data with high spa-
tial and temporal resolution were obtained with the
French-Italian THEMIS solar telescope. We used spec-
tra were obtained in the H α -line and in the lines form-
ing within a wide range of photospheric heights: FeI
λ λ 630.15, 630.25, and 630.35 nm and TiI λ 630.38
nm. EBs evolved in the region magnetic flux that were
emerging at the time. Changes in the velocity and di-
rection of chromospheric and photospheric matter mo-
tion in the region of Ellerman bombs and in their im-
mediate vicinity at different stages of EBs evolution
were determined and analyzed.
Temporal variations in the line-of-sight velocities
(Vlos) of the chromospheric matter at a level of the H α
core formation showed two periods in the velocity en-
hancement, containing several individual peaks. The
maximum Vlos was –9 and 8 km/s toward and from
the observer, respectively. Rapid upward and down-
ward plasma streams (where Vlos reaches –80 and 50
km/s, respectively) were sometimes observed.
It was found that upflows were predominant at all
levels of the AR photosphere. At the same time, Vlos
decreased considerably in the region of EBs. Appar-
ently, the small-scale downward flows induced by mag-
netic reconnections were superimposed onto the large-
scale upward motion of the new magnetic flux plasma.
The line-of-sight velocity in the central part of EB-1
and EB-2 varied from –1 to 0 km/s and from –1 to 0.2
km/s in the upper photospheric layer and from –1.6
to –0.2 km/s and from –1.1 to 0.25 km/s in the lower
layer of the photosphere, respectively.
The studied features of temporary changes in the
line-of-sight velocities of the chromospheric and photo-
spheric matter during the formation and development
of Ellerman bombs indicate that they affect both the
photosphere and the lower chromosphere.