We investigated the structure of magnetic field and vertical electric currents in two active regions. Electric currents were calculated from the observations of transverse magnetic field. There exist two systems of vertical electric currents in an active region; a system of local currents and global one. The globál current is about 2.10^^ A. In the leading part of the active region it is directed upward, and in the tail - downward and is plausibly determined by the global rotation of plasma. The flare activity is dosely connected with the value and direction of both local and globál currents: the flares tend to appear in places with upward currents. The sensitivity of Hα„ emission to the sign of current implies that the charged particles accelerated in the upper parts of magnetic loops are responsible for these formations.
We describe the course of events during the evolution of the 300 keV, 3B/M7 June 26, 1983, 14:07 UT flare, as observed at the Crimean Astrophysical Observatory. We show directly as they developed a/ preflare microprominence uprise (Fig. 1)
b/ emisslve-surge flare onset c/ flaring arch system during the maximum flare phase (Fig. 2) d/ flaring arch cooling, which dlffers from the proper "post-flare loops" phenomenon (Fig. 3). The maximum rate of the upward surge’s extension, along its
axis, was 360 km s-1.
Thls paper Is devoted to the solar Hα-flare and cm-burst on
July 12,1982. It Is shown scenarlo of the flare-burst development: the
change of magnetlc fleld - Hα-flare - the burst of the radlo emission
intensity.
Simultaneous photographic observations in Hα, and photoelectric observations in Hel γ 10830 line are analyzed for two flares of importance sf and 1B. For the estimation of physical conditions in the chromosphere of flares the non-LTE calculations of the Hα and γ 10830 line profiles were made for a number of model atmospheres. Comparing the observed values of Hα and γ 10830 line intensities vvith calculated ones, we derived the temperature
changes during the development of active formations for two levels of chromosphere (Ihe levels of Hα and γ 10830 line formation).