ИСТИНА

A classification of solar wind (SW) streams according to the main hydrodynamic parameters − a combination of the velocity (fast or slow), temperature (hot or cold) or density (dense or rarefied) of protons − is considered. According to this approach, we specify eight types of SW: fast-hot-dense (fhd), fast-hot-rarefied (fhr), fast-cold-dense (fcd), etc. As an additional parameter, the proton plasma beta is taken into account for description of the magnetic state of the SW streams. The listed types of SW occur with different frequencies, depending on the phases of the solar activity cycles. This classification is compared with the classical division of SW streams into high-speed flows from coronal holes, CME and slow solar wind from the streamer belt. The comparison is carried out for the events in August 2010 and May 2011 when the interaction of two CME and CME with a high-speed solar wind stream from the coronal hole, respectively, was observed. In both cases there was the rare fcd-type of the wind. We concluded that the classical description of the large-scale structure of SW on the scale of hours and days, in particular, consideration of the SW ionic composition, makes it possible to determine the nature and source of SW streams, whereas consideration of the hydrodynamic parameters including beta is useful for a detailed description of the small-scale structure (minutes) of complex regions appeared in the cases of interaction of several streams in the heliosphere.