| Abstract : | From long radio waves to short X-rays, the Sun releases radiation across a wide variety of energy spectrum. It is common to record the solar emission as a function of both frequency and time because the solar radio flux at different frequencies has a higher degree of correlation with all other solar phenomena. Thus, solar radio emissions are a very useful indicator of major solar activity, such as sunspot cycle or magnetic reversal cycle. The solar radio flux emissions changes gradually in intensity. This paper examines long-term temporal and spatial variations in the solar rotation (more than six solar cycles) by investigating radio emission from various layers of the solar atmosphere during the years from 1952 to 2022. The present study makes use of annual time series of disk integrated radio flux data at five different wavelengths (3.2, 8.0, 10.7, 15, and 30 cm) obtained from LASP Interactive Solar Irradiance Data Centre (LISIRD). Periodicity present in a time series cannot be obtained directly from the time series itself. To obtain periodicity present in a time series, statistical tools like autocorrelation, FFT, wavelet analysis, Lomb-Scargle Periodogram (LSP) etc. can be used. In present work, the periodic component present in the variation of time series is estimated through Lomb-Scargle Periodogram (LSP), because LSP can also deal with the time series having some data gaps. The rotation period estimated for five radio emissions through LSP show continuous temporal and spatial variation throughout the years. The smoothened rotation period shows the presence of ∼22-yr periodic and ∼11-yr components in it. The 22-year component most likely be related to the solar magnetic field reversal (Hale) cycle, while the 11-year component is obviously related to the sunspot (Schwabe) cycle. Detail result would be presented in the paper. |
