Comparative Study of Solar Rotation of Transition Region and Corona using Solar Irradiance and Radio Flux

Abstract

We study the temporal variation of solar rotation profiles based on solar irradiance at 93.5 nm and solar radio flux at 10.7 cm originating from the transition region and lower corona, respectively. The autocorrelation technique is used to calculate the period in periodic time series data. The sidereal rotation periods for normalized and detrended data are studied for 2011 – 2021. The sidereal rotation periods for solar irradiance and radio flux for 2011 – 2021 vary from 22.75 to 26.17 days and 19.42 to 28.14 days, respectively. The mean of the sidereal rotation periods for solar irradiance and radio flux are 24.76 and 23.76 days, respectively. The mean sidereal rotation period for solar irradiance is higher than the mean sidereal rotation period for solar radio flux. The sidereal rotation period for solar irradiance is greater than or equal to the sidereal rotation period for solar radio flux for almost all the years between 2011 and 2021. It is found that the lower corona rotates faster than the transition region during 2011 – 2021, i.e., the lower corona is found to be moving 4% faster than the transition region during 2011 – 2021. We found a linear relationship between the normalized daily irradiance and radio flux with a correlation coefficient of 0.986. Using cross-correlation analysis, we investigated a phase relationship between solar irradiance and radio flux and found no time lag between solar irradiance and radio flux.