Research Article

Solar flare forecasting using morphological properties of sunspot groups

INAF – Osservatorio Astrofisico di Catania, Via S. Sofia 78, 95123 Catania, Italy

^* Corresponding author: mariachiara.falco@inaf.it

Received: 1 February 2019
Accepted: 3 May 2019

Abstract

We describe a new tool developed for solar flare forecasting on the base of some sunspot group properties. Assuming that the flare frequency follows the Poisson statistics, this tool uses a database containing the morphological characteristics of the sunspot groups daily observed by the Equatorial Spar of INAF – Catania Astrophysical Observatory since January 2002 up today. By means of a linear combination of the flare rates computed on the base of some properties of the sunspot groups, like area, number of pores and sunspots, Zurich class, relative importance between leading spot and density of the sunspot population, and type of penumbra of the main sunspot, we determine the probability percentages that a flare of a particular energy range may occur. Comparing our forecasts with the flares registered by GOES satellites in the 1–8 Å X-ray band during the subsequent 24 h we measured the performance of our method. We found that this method, which combines some morphological parameters and a statistical technique, has the best performances for the strongest events, which are more interesting for their implications in the Earth environment.