Long-Term Datasets for the Understanding of Solar and Stellar Magnetic Cycles Proceedings IAU Symposium No. 340, 2018 D. Banerjee, J. Jiang, K. Kusano & S. Solanki, eds. c  International Astronomical Union 2018 doi:10.1017/S1743921318001953 Search for Correlation between Solar Flare Count and Mean Solar Magnetic Field Chandan Joshi, B. Sobha and Vishwas Deep Joshi JECRC University, Jaipur, Rajasthan, India email: chandan.joshi@jecrcu.edu.in Abstract. An investigation for search of correlation between the daily observations of mean magnetic field and daily flare count number in different class is studied here. The daily ob- servations for mean magnetic field presented here are taken by Wilcox Solar observatory and daily flare count in different X-ray class is provided by National Centers For Environmental Information. Keywords. Sun: flares, Sun: magnetic fields 1. Introduction The perturbations in magnetic field are root cause of solar activity and hence space weather. The solar flares are a sudden release of large amount of magnetic energy in few seconds Somov, B. (2004), Tandberg-Hanssen & Emslie(2009), Shibata & Magara (2011), Fletcher et. al. (2011). The studies K. Kusano et al.(2012), Shibata & Magara (2011) reveal the dependence of flare occurrence on the structure and evolution of of local magnetic field over a small temporal scales. The daily solar mean magnetic field show periodic behaviour with longer periods of 11 years, and other periods of 1-2 years, 80-200 days, and 13-26 days as anlysed by Boberg et. al. (2002). The daily number of solar X-Class flares also show periodic behaviour with periodicities of occurence in different class in the range of 3 months to 400 months as studied by Gao & Xu (2016A) The periodicity of flare occurence also varies from cycle to cycle Gao & Xu (2016B). Here in this study we plan to analyze existance any correlation between the evolution of daily mean magetic field and daily flare count in different x-ray class. 2. Overview The data presented here is taken from Wilcox solar observatory. The Wilcox observa- tory observes the daily mean magnetic field using Babcock type magnetograph Babcock (1953) since 1975 Scherrer et al. (1977) using Zeeman spliting in Fe I line at 5250 ˚ A. The data for solar flare numbers can be downloaded from web site of National Geophysical Data Center (NGDC) https://www.ngdc.noaa.gov/stp/space-weather/solar-data/ solar-features/solar-flares/x-rays/goes/xrs/. The mean magnetic field have some breakes which are interpolated using spline interpolation. The date for which flare count is unavialable we have taken it as zero. We have used Pearson method r = N ∑ XY - ( ∑ X ∑ Y )  [N ∑ x 2 - ( ∑ x) 2 ][N ∑ y 2 - ( ∑ y) 2 ] (2.1) to calculate the correlation coefficient between the daily solar mean magnetic field and so- lar flare count in different class. We have used the R software to calculate the parameters computationally. 77 https://www.cambridge.org/core/terms. https://doi.org/10.1017/S1743921318001953 Downloaded from https://www.cambridge.org/core. IP address: 3.236.249.176, on 01 Aug 2021 at 13:27:16, subject to the Cambridge Core terms of use, available at