Abstract Details

Conference ID: ASI2017_973
Title : Solar Activity in association with Geomagnetic Activity during Solar Cycles 22-24
Authors and Co-Authors : Prithvi Raj Singh,A.C. Pandey, C. M. Tiwari,A.K. Saxena Department of Physics A.P.S. University, Rewa, M.P. – 486003
Abstract Type : Poster
Abstract Category : Sun and the Solar System
Abstract : The 11-year cycle of solar activity is characterized by the rise and fall in the surface area of sunspots. A solar activity in association with the sunspots including; geomagnetic activity; individual solar cycles are characterized by their maxima and minima, as well as hemispheric asymmetries. Comparing the corrected whole sunspot areas to the sunspot number the two quantities are indeed highly correlated as well as geomagnetic activity with sunspot number. The smoothed monthly geomagnetic index (aa) tends to remain high during the declining phase of each solar cycles. The high levels of geomagnetic activity are found even when the sunspot number is quite low for the period (1986-2015). Taking the ratio of the hemispheric differences to the square root of the sums provides a measure of asymmetry that does not tend to favour either maximum or minimum phases. The normalized asymmetry usually switches from north-dominant to south-dominant on time scales shorter than an 11-year sunspot cycle as well as geomagnetic activity. As smoothed, normalized north-south asymmetry in sunspot area and geomagnetic activity, the northern hemisphere activity leads to the fact that in the southern hemisphere, the north will dominate early in the cycle while the south will dominate in the declining phase of solar cycles. We have made an investigation of the patterns of periodicities and their evolution for sunspot number and geomagnetic activity by Fast Fourier Transform (FFT) and Wavelet Transformation, and found that they have almost similar periodicities of ~3.25 and 2.25 years during the period (1986-2015).