Rotational properties of solar EUV corona using SDO/AIA-19.3-nm observations
Jaidev Sharma, Anil K. Malik, Hari Om Vats, Shyamal Kumar Banerjee
Abstract
ABSTRACT In this article, we present the differential rotational profile of extreme ultraviolet (EUV) corona. For this purpose, we used observations with high resolution obtained from SDO/AIA at 19.3-nm wavelength from years 2011 to 2021. We found the higher rotation rate of the equatorial segment (14.8 deg d−1) which drops about 13.5 deg d−1 on both sides of the poles. The average rotation rate (i.e. from 2011 to 2021) of the equatorial region of EUV corona is found to be higher than that of the photosphere, chromosphere, transition region, and corona. Furthermore, the average rotational gradient (as a function of latitude) of the EUV corona is lower than that of the photosphere and transition region. Interestingly, we found a significant correlation of the hemispheric rotational asymmetry with the solar activity indicator (SSNs) and EUV emission. The cross-correlation analysis indicates that the hemispheric rotational asymmetry leads the solar activity indicator (SSN) and EUV emission by about 1.5 months.