LARGE-SCALE STRUCTURE OF SOLAR-WIND AND ITS RELATIONSHIP WITH SOLAR CORONA - PROGNOZ-7 OBSERVATIONS

On the basis of selective measurements of proton and alpha-particle bulk parameters and magnetic field on board the Prognoz 7 satellite, the structure of solar wind is studied and compared with the known structure of solar corona. For that purpose the magnetic field value, B, proton temperature, T(p), ratio of thermal and magnetic pressures, beta = nkT(p)/(B2/8-pi), and relative helium abundance, n-alpha/n(p), are represented as distributions on the n-V(p) (solar wind ion density-proton velocity) plane. The values and different behaviour of these parameters on the n-V(p) plane allow us to identify five regions (types of solar wind streams), which may be connected with well known solar corona structure and events: (1) heliospheric current sheet; (2) streams from closed coronal magnetic field regions (streamers); (3) streams from open magnetic field regions (coronal holes); (4) disturbed solar wind streams at large angles relative to the solar meridians of non-stationary events in the corona; and (5) disturbed streams at small angles relative to the meridians of non-stationary events, including the matter of coronal mass ejections. Distributions of velocity difference, V-alpha - V(p), and temperature ratio, T-alpha/T(p), alpha-particles and protons on the n-V(p) plane show that preferential acceleration (V-alpha > V(p)) and heating (T-alpha/T(p) greater-than-or-equal-to 4) of alpha-particles are generally observed in streams from coronal holes.