ИСТИНА

Ion composition of the solar wind (SW) streams is a well-defined indicator of their origins and processes of evolution in the corona and heliosphere. The current report is a review of recent results on investigation of the link between ion composition of the in-situ measured solar wind streams and properties of their solar origins in Cycle 23 and 24. 1. Statistics of SW stream types has shown that at high solar activity (Cyc 23) the yearly numbers of Interplanetary Coronal Mass Ejections (ICMEs) better correlate with those of Coronal Mass Ejections (CMEs) associated with flares, whereas in the weaker Cyc 24 ICMEs higher correlate with CMEs without flares. 2. For the period from beginning of 2010 and August 2011 we identified solar origins of 23 ICMEs and found that in 48% of cases streams from multiple sources interacted in the heliosphere, so they produced complex multi-source events (MS). 3. By ion composition parameters, we classified MS events as cases with weak and strong CME-CME interaction and CME-HSS interaction and show that profiles of their parameters and duration are seriously differ from those of the single-source streams. 4. For the case of ICME of 4 August 2011 we demonstrated that formation of a flux rope and CME in the corona and their ion composition can be simulated using the ideal MHD modeling of the flux rope/CME formation and analytical consideration of the ion charge state evolution of the plasma in the corona using EUV and MF data combined with consideration of the ionization/recombination balance. Thus, consideration of ion composition of the SW plasma for SS as well as for MS events provides an effective means for understanding and modeling processes of the SW formation.