Session 2: Solar, Planetary and Space Physics

Title:  Flow Sources and Formation Laws of the Solar Wind Streams
Author(s):  N.A. Lotova, V.N. Obridko, K.V. Vladimirskii, M.K. Bird, P. Janardhan (Oral)
Contact: Natalia A. Lotova, IZMIRAN, 

The large-scale stream structure of the solar wind flow is studied in the main acceleration zone from 10 to 40 solar radii from the Sun. Four independent sets of experimental data were used: radio astronomical observations of radio wave scattering using the large radio telescopes of the Lebedev Physical Institute; dual-frequency Doppler solar wind speed measurements from the Ulysses Solar Corona Experiment during the spacecraft's solar conjunctions in summer 1991 and winter 1995; solar magnetic field strength and configuration computed from Wilcox Solar Observatory data; white-light coronagraph images obtained from ground-based eclipse and SOHO observations. Both the experimental data on the position of the transonic region of the solar wind flow and the solar wind speed estimates were used as parameters reflecting the intensity of the solar wind acceleration process. Correlation studies of these data with the magnetic field strength in the solar corona revealed several types of solar wind flow. Different types of streams arise in coronal regions differing by their magnetic field strength and structure. A total of four specific types, two of high-speed and two of low-speed, were revealed.