Spatial distribution of turbulence characteristics in the inner solar wind

Abstract

Data on the spatial distributions of turbulence characteristics in the inner solar wind are reported. Spectral indices for the outer and inner turbulence scales have been obtained in radio occultation experiments using signals from several spacecraft at different phases of the solar cycle. The characteristics of turbulence in the slow, low-latitude solar wind remain, on average, constant during the solar cycle. The outer turbulence scale in the fast, high-latitude solar wind appreciably exceeds that of the slow, low-latitude wind at the solar minimum. The new data confirm that the transition from the acceleration region to the steady-flow region is accompanied by a change in the turbulence regime. This change in the turbulence regime takes place at greater distances from the Sun for the fast than for the slow solar wind.