Abstract Details
| Name: Krishna Kumar Pandey Affiliation: Osmania University Hyderabad Conference ID: ASI2015_609 Title : Cyclic evolution and north-south asymmetry of soft X-ray flare index during solar cycles 21, 22, and 23 Authors and Co-Authors : K. K. Pandey 1, 3, Bhuwan Joshi 2, R. Bhattacharyya 2, and Upendra Kushwaha 2 1. Department of Astronomy, Osmania University, Hyderabad 500 007 2. Udaipur Solar Observatory, Physical Research Laboratory, Udaipur 313 004, India 3. Bapu Intermediate college Sadat Ghazipur, U.P, 275204 Abstract Type : Poster Abstract Category : Sun and the Solar System Abstract : In this paper, we present a comprehensive statistical study to investigate the temporal and spatial distribution of solar flare activity during solar cycles 21, 22, and 23. We characterize the flare activity within a time interval by soft X-ray flare index (FI) rather than traditional flare counts. In general, FI shows a good correlation with other parameters of solar activity. We find that FI correlates much better with sunspot area than sunspot number. The study reveals a significant north–south asymmetry of FI which exhibits variations with the phases of solar cycle. The significance of north-south asymmetry is assessed by student’s t-test. We find that the reliability and persistency of asymmetry significantly increases when the data is averaged over longer periods while an optimum level is achieved when data is binned for ∼11-12 Carrington rotations. The observed shift in asymmetry of FI from one hemisphere to the other near the maximum phase of solar cycle is in agreement with previous studies carried out with other solar activity indices. The time profile of FI suggests a dual-peaked structure of solar cycle which is the most prominent during solar cycle 22. |