New ionospheric index for Space Weather services

Modern society replies on the ionosphere for technology such as radio navigation and telecommunications. However, this is not a static environment and its characteristics can be affected by solar phenomena such as coronal mass ejections (CMEs) and high-speed solar winds. In this paper we present a set of space weather parameters (e.g. type and velocity of CMEs, X-ray flux, the velocity of high-speed solar wind) that allow to identify the dominant physical connections between ionospheric dynamics and these two solar phenomena. The study uses vertical and oblique sounding data of the ionosphere obtained during several space weather events occurring in solar cycle 21, 22 and 24. We propose and discuss the advantage of a new ionospheric index for defining how CMEs and high speed solar streams, as global events of solar activity, influence the values of the parameters used to characterize the ionosphere.