Correlation analysis of solar flux absolute measurements at 161 and 245 MHz

Abstract

Solar emission in meter waves originates from upper layers of the solar corona. We present absolute measurements of solar flux from Irkutsk Incoherent Scatter Radar (161 MHz frequency) and Learmonth Observatory (245 MHz frequency). We perform correlation analysis to investigate the relation between solar flux values at different frequencies. Background emission of the quiet Sun is within the expected limits. We examine the behavior of background and slowly-varying emission components during a solar cycle. By comparing the Pearson correlation coefficient with the Spearman rank correlation coefficient, we have found that the dependence of the meter flux on the F10.7 index is non-linear. The correlation between solar flux measurements at 161 and 245 MHz appeared to be lower than that with the F10.7 index. Analysis of daily correlation and autocorrelation shows a diurnal variation that introduces an error into the measurements.