On Correlation of the Interplanetary Scintillation Level and Solar Wind Speed

Abstract

The paper reports the results of observations of the interplanetary scintillation of a compact radio source 3С 48 at the descending phase 24 solar cycle. The observations were conducted using a BSA LPI radiotelescope at frequency of 111 MHz. A comparison was made between an index (level) of the scintillation and solar wind speed, which was computed by a width of the scintillation temporal spectra. Complete series of observations from 2015 to 2019 displays a weak declining dependence of the scintillation level on the solar wind speed; the correlation, however, is rather low (averages about –0.15) due to a significant scatter in the data. With averaging over one-year intervals, the correlation coefficient module increases almost up to 1 with scintillation index in the mean approximately inversely proportional to solar wind speed. The paper further elaborates on a possible relationship between a spatial-temporal structure of the scintillation level and mean plasma density of the solar wind.