2023IonosphericStormsData

Data for a paper presenting a deep and comprehensive multi-instrumental analysis of two distinct ionospheric storms occurring in March and April 2023. We investigate the ionospheric response in the middle-latitudinal European region utilizing ionospheric vertical sounding at five European stations: Juliusruh, Dourbes, Pruhonice, Sopron, and a reference station, San Vito. Additionally, we employ Digisonde Drift Measurement, Continuous Doppler Sounding System, local geomagnetic measurements, and optical observations. We concentrate on the F2 and F1 region parameters and shape of the electron density profile. During the March event, a pre-storm enhancement was observed, characterized by an increase in electron density up to approximately 20% at northern stations, with minimal effect observed at San Vito. The observed decrease in foF2 during both events, except at San Vito data, conforms to the typical pattern of negative storms. The most significant change in ionospheric characteristics was the presence of a so-called G-condition, when no information about the state of the ionosphere above the F1 layer is obtained from ground-based observation. Further, an alteration in the shape of the electron density profile, notably captured by the parameter B0 is observed. A substantial increase in B0, by several hundred percent, was noted during both events on the day of the geomagnetic disturbance, as well as on the subsequent day with low-to-moderate geomagnetic activity. During both storms, the critical frequency foF1 decreased at all stations including San Vito. Changes in electron density in the F1 region indicate plasma outflow during morning hours. Distinct and persistent oblique reflections from the auroral oval were observed on the ionograms for several hours during both events and these observations were in agreement with optical observations of auroral activity and concurrent rapid geomagnetic changes at collocated stations. Results from the Continuous Doppler Sounding System and Digisonde Drift Measurement reveal vertical movement of plasma up to ±80 m/s, showing excellent agreement. Analysis of observed vertical plasma drifts and horizontal component H of magnetic field in Czechia and Belgium suggest that vertical motion of the F-region plasma is caused by ExB plasma drift.