Abstract Details

Name: Satish Chandra
Affiliation: P. P. N. PG College, Kanpur
Conference ID: ASI2021_328
Title : Long term variation in solar rotation and its dependence on solar cycles
Authors and Co-Authors : Satish Chandra (Pt. Prithi Nath P G College, Kanpur, UP, India), Vivek Kumar Singh (Sam Higginbottom University of Agriculture Technology and Sciences, Prayagraj, UP, India)
Abstract Type : Poster
Abstract Category : Sun and the Solar System
Abstract : Variations in solar rotation (temporal and spatial both), is still an arguable concern of solar physics that can also be estimated by the flux modulation method. The work presented here is an effort to investigate the long term variations (more than four solar cycles) in the solar rotation by analyzing the radio emission that escapes from various altitudes above photosphere of solar atmosphere. The radio flux data at various frequencies (245-15400 MHz) recorded during years 1967 to 2010 at Sagamore Hill Solar Radio Observatory, Massachusetts, USA and other observatories are used to generate time series. The periodicities present in the time series can be estimated through various statistical methods. Here in our case, Lomb-Scargle Periodogram (LSP) is used to estimate rotation period present in the time series, due to its ability to deal with unevenly sampled data. The rotation period estimated through LSP analysis shows continuous temporal and spatial variation throughout the years. The smoothened rotation period shows the presence of ∼ 11-yr and ∼ 22-yr periodic components in the time series. The ∼ 22-yr component must be linked to the solar magnetic field reversal (Hale) cycle and the ∼ 11-yr component, obviously to the sunspot (Schwabe) cycle. Besides these two components, random components are also prominently present in the analyzed data. The cross-correlation between the yearly averaged sunspot number and the rotation period obtained shows strong and almost in phase correlation with 11-yr Schwabe’s and 22-yr Hale cycle. The detail outcome of study would be presented in the paper.