2011/03/15 by Satish Chandra, Hari Om Vats · 38 citations
Physics and Astronomy · #Coronal plane #Electrical and Electromagnetic Research #Flux (metallurgy) #Rotation (mathematics) #Rotation period #Scientific Research and Discoveries #Sidereal time #Solar and Space Plasma Dynamics #Solar cycle #Solar physics #Solar rotation #Sunspot #astro-ph.SR
paper · pdf · doi:10.1111/j.1365-2966.2011.18611.x
published in Monthly Notices of the Royal Astronomical Society 414(4), 3158-3165 (Oxford University Press) · 9 pages, 5 figures, Accepted for publication in MNRAS
arxiv created 2011/03/15 · openalex publication_date 2011/05/02 · arxiv updated 2015/05/27 · openalex created_date 2019/06/27 · openalex updated_date 2026/08/05
This study is an attempt to investigate the long-term variations in coronal rotation by analysing the time-series of the solar radio emission data at 2.8 GHz frequency for the period 1947–2009. Here, daily adjusted radio flux (known as Penticton flux) data are used. The autocorrelation analysis shows that the rotation period varies between 19.0–29.5 sidereal days (mean sidereal rotation period is 24.3 d). This variation in the coronal rotation period shows evidence of two components in the variation: (1) 22-yr component which may be related to the solar magnetic field reversal cycle or Hale's cycle; and (2) a component which is irregular in nature, but dominates over the other components. The cross-correlation analysis between the annual average sunspot number and the coronal rotation period also shows evidence of its correlation with 22-yr Hale's cycle. The 22-yr component is found to be almost in phase with the corresponding periodicities in the variation of the sunspot number.