Propagation observations of the solar wind near the sun

New measurements of the solar wind electron density between 2 and 22 solar radii are reported. The spatial spectrum between scales of 100 m and 100 km and between 1000 km and 10,000 km is estimated, and radar observations are used to provide independent estimates of the mean electron density and its radial gradient. The spectra apparently show the onset of a dissipative process at an 'inner scale' of the order of 2 km at distances of 4-6 solar radii. The inner scale increases monotonically with radial distance. Below the inner scale, the spectra exhibit a local flattening before steepening again toward very low frequencies. This flattening, which occurs at scales of 3-300 km, represents a substantial excess of turbulent power over what would be predicted by a Kolmogorov extrapolation from the larger scales. 42 references