Total sunspot number calculation based on flare production potential of sunspot groups: reconstruction of SSN and its relation to some geomagnetic indices

Abstract

In this study, we modified the previously introduced X-ray flare production potential (FPP) of each modifiedZurich sunspot group based on its X-ray flare peak flux. Then, using these FPPs, the daily total sunspot number (Zurichnumber) calculation equation was modified; thus, new sunspot number data (CRz) were produced. We also comparedISSN and CRz with some geomagnetic indices (Dst, the maximum CME speed, and Ap indices). We found that theCRz data describe the geomagnetic indices quite well compared to ISSN. By using the regression equation between CRzand the sunspot area, the CRz dataset was recalculated back to 1874. Those reconstructed datasets were compared toobservational data, and it was found that reconstructed and observed monthly datasets show very good agreement. Theonly small differences exist in maxima and minima of cycles.