| Abstract : | Solar rotation responsible for various solar activities is an unanswered problem of solar physics. Sun emits radiation in all frequency regimes starting from radio waves to gamma rays. Hence Sun could be observed in most of such frequency regimes. In recent decades the information about solar rotation strongly improved. Solar rotation can be measured by tracking the tracers across the solar disk,or via spectroscopy, or via flux modulation method using radio waves, X-rays, and UV rays that emitted out in the space. SDO, a space mission of NASA to understand the magnetic changes in Sun. Analysis of SDO data could build up the capability of forecasting solar variations that can affect life on the Earth. SDO/AIA data can be used to estimate the rotation of solar atmosphere, which in turn used to draw information about change in solar magnetic field as variation in sunspot cycle and Hale’s cycle. In present work feasible variation in latitudinal solar rotation is estimated. To find latitudinal variation in solar rotation, the SFD images at wavelengths (193, 211 and 304 Å), at a cadence of one per day, obtained from SDO/AIA have been used for each year of the whole mission period (2011-2022). In flux modulation method, the variation in flux emitted over the latitudinal bin(formed on equally separated latitude region of SFD images that extended from 80oN to 80oS) on solar disc generates annual time series for each latitude. The periodogram analysis of each time series of any latitude bin on the SFD images for a year gives the estimation of solar rotation period as a function of latitude. Estimated result shows sometimes rigid rotation and sometimes differential rotation of solar corona and transition region in different epoch. This variation in solar rotation found to be linked with the solar activity cycle. |
