Abstract Details

Name: Jaidev Sharma
Affiliation: Department of Physics, C.C.S. University, Meerut
Conference ID: ASI2021_429
Title : Hemispheric Rotational Asymmetry and Solar Activity
Authors and Co-Authors : Jaidev Sharma, Department of Physics,C.C.S.University, Meerut-250004, Anil. K. Malik, Department of Physics,C.C.S.University, Meerut- 250004, Brajesh Kumar, Udaipur Solar Observatory, Physical Research Laboratory, Badi Road, Udaipur-313004, INDIA and Hari Om Vats,Space Education and Research Foundation, Ahmedabad, INDIA
Abstract Type : Poster
Abstract Category : Sun and the Solar System
Abstract : Using the observations of STEREO-A instrument, we present the results of hemispheric asymmetry in coronal rotation and its relation with solar activity. For this purpose, we used the images at 30.4, 19.5 and 28.4 nm during the period from 2008 to 2018 covering 24th solar cycle. Here, we applied flux modulation method on the solar full-disk (SFD) images having size 512×512 pixels. We have extracted the time series of hemispheric Extreme Ultraviolet (EUV) intensity variation for both the hemispheres (North and South). Each hemispheric EUV flux is auto-correlated up to lag 150 days and first peak of autocorrelogram is fitted by Gaussian function. The time value of Gaussian function fitted to the first secondary maximum represents the synodic rotation period. Present investigations show that in solar maximum period i.e. from 2011 to 2014, hemispheric asymmetry in rotation rate is highest and this gradually drops on both sides of maximum phase towards minimum phases (i.e. from 2008 to 2011 and 2014 to 2018). Moreover, hemispheric asymmetry in rotation rate leads the sunspot numbers by ∼18 months. This indicates that hemispheric rotational asymmetry may be contributing in the formation of sunspots.