Variations of the solar-wind stream structure in the region of subsonic flow during the 11-year solar cycle

The large-scale stream structure of the solar wind near the Sun and its evo lution during the Ii-year solar activity cycle are investigated. The study is based on observations of scattering of the radiation from compact natura l radio sources at radial distances R less than or equal to 14R(s) (R-s is the solar radius). Regular observations were conducted in 1981-1998 on the RT-22 and DKR-1000 radio telescopes of the Russian Academy of Sciences at P ushchino, at lambda = 1.35 cm and 2.7 m, respectively. The radial dependenc es of the interplanetary scintillations m(R) and the scattering angle 2 the ta (R) are considered together with the structure of large-scale magnetic f ields in the solar corona at R = 2.5R(s). The entire range of variations in the level of scattering and the associated helio-latitude flow structures in the subsonic solar wind forms over the 11-year solar cycle, as a direct result of the large-scale structure of the evolving magnetic fields at the source of the solar-wind streamlines. (C) 2000 MAIK "Nauka/Interperiodica".