A study of solar-cycle variation of coronal rotation using the SDO/AIA 211 Å observations

摘要

We present the results of variation in the rotational profile of solar corona for the period from 2012 to 2017, covering the peak and descending phases of the Solar Cycle 24. There is a clear evidence of North-South asymmetry in the solar coronal rotation. For this work, we used flux modulation method analysis for the solar full disk images (SFD) obtained at 211 Å by the Atmospheric Imaging Assembly (AIA) telescope on board Solar Dynamics Observatory (SDO) space mission. The SDO has three scientific instruments namely, the Extreme Ultraviolet Variability Experiment (EVE), the Helioseismic and Magnetic Imager (HMI) and the Atmospheric Imaging Assembly (AIA). SDO mission was launched by NASA on 11 February 2010 aimed to study the dynamics of Sun's surface and its atmosphere. AIA filters cover 10 different wavelength bands, chosen to reveal key aspects of solar activity at different heights in the solar atmosphere. Solar full disc (SFD) images obtained at the extreme ultraviolet wavelength (EUV) 211 Å by AIA are available in different sizes: 512 × 512, 1024 × 1024 and others with a very less data gap.