The proces of solar eurge formation is atudied by means of computer simulations on the basis of a two-dimensional MHD model. It is assumed in the model that a small-scale magnetic field is penetrating in a compressible plasma medium with physical parameters near to those of the lower chromosphere. Computer simulations show that nonlinear effects lead to formation of relatively denser and hotter structures. This phenomenon is discussed as a link unifying the magnetic and nonmagnetic
mechanisms of surge formation proposed by various authors.
Different modes of magnetic field - chromospheric plasma interaction are possible under the assumption that the energy is released impulsively. One of them leads to the creation of
small-scale impulsive structures such as forced plume and dynamical stable current filaments. These structures we consider as basic MHD elements of the plasma of the solar active phenomena. We show that such a structuralization plays an important role in the process of solar surge formation and dynamics.
We present the preliminary results of a study of the solar prominences observed at Lomnický Štít coronal station with the 20 cm coronagraph during the ascending phase of cycle 22. The observational material was processed and a catalogue of prominences was prepared. On the basis of this catalogue some statistical results were obtained. They concern mainly the latitudinal, longitudinal and time distributions of the prominences and their basic morphological characteristics.