Temporal and spatial variability of EUV flux at 094 Å and its relationship with sunspot activity

Abstract

We study temporal and spatial variability of coronal EUV flux/emission/intensity at 094 Å and investigate latitudinal profiles of the EUV flux from centre to poles of solar disc based on daily image obtained from the SDO/AIA for the period from 10 February 2011 to 20 November 2021. Solar coronal activities (regions of high EUV flux) patterns of latitudinal EUV flux, latitudinal north-south asymmetry of EUV flux and relationship between EUV flux and sunspot numbers are discussed. The disc-integrated normalized EUV flux is found positive correlated with SDO/EVE normalised solar irradiance. It is shown that there are two kinds of migration of solar coronal activities in distribution of EUV flux at 094 Å during the rising phase of solar cycle 24: one towards the equator and another towards the poles in both hemispheres. The peaks of EUV flux occur in the region −25∘ to +25∘ solar latitudes in the years 2011 and 2014. The latitudinal EUV flux in northern and southern hemispheres have asymmetrical behaviour. The dominancy of EUV flux in northern hemisphere is found only at 5∘, 15∘, and 75∘ solar latitudes whereas the dominancy of EUV flux in southern hemisphere is found at the rest of the solar latitudes. We found that the dominancy of EUV flux in both the hemispheres is a function of time and solar latitude. The EUV flux is dominated in the southern hemisphere during the entire period. The EUV flux is positive correlated with sunspot numbers for full disc, northern and southern hemispheres and their relationship is found linear and significant.