Observations of field-aligned density microstructure near the Sun

摘要: Radio scattering observations made with multiple antennas provide a direct measure of the two-dimensional microstructure solar wind. Previous antenna have shown that at scales order 10 km becomes highly field-aligned inside 6 RS [e.g., Armstrong et al., 199O]. Single observations, which can only radial cut through microstructure, larger than 1000 Kolmogorov spectrum, whereas smaller-scale structure has flatter spectrum and is considerably enhanced above “background” Coles 1991]. Here we present new “angular broadening” in 1990 1992. These confirm near Sun, they show it elliptical symmetry, axial ratio changes quite abruptly RS. We also simultaneous measurements 9 anisotropy on 1 to 30 200 3000 km. Significant was seen smaller but not scales. This suggests process responsible for anisotropic distinct from larger-scale, more isotropic structure.