## 3 Data and Methods
### Ionospheric Data  
To investigate the ionosphere for potential disturbances associated with the Fano EQ, data from ionosonde and satellite sources were analyzed. From the ground, ionosonde measurements can detect the critical frequency of the F2 layer (foF2), the height (hmF2) of the main electron density peak, and also the information of the sporadic E (Es) layer (such as its height, h'Es; its critical frequency, foEs; and the blanketing frequency, fbEs), which can represent the variations of the corresponding layers. Low Earth Orbit (LEO) satellites can detect the in situ plasma parameters and electromagnetic field. The ionospheric station of Rome (43.98\({}^{\circ}\) N; 13.32\({}^{\circ}\) E) is located 251.44 km from the epicenter, so within the EQ preparation zone according to the formula by [PERSON] et al. [57]. Hourly data manually scaled by an experienced operator from the ionograms recorded with the Advanced Ionospheric Sounder (AIS-INGV) [58] were used in this study [59]. Ionospheric anomalies are defined by significant deviations in the parameters h'Es, fbEs, and foF2 compared to a specified background level determined by 27-day hourly running medians centered on the observation day. Specifically, these deviations are calculated according to the following expressions and must satisfy the following criteria, provided they occur within a few hours under geomagneticly quiet conditions specified by daily geomagnetic index values Ap < 9 nT:  
\[\Delta H^{\prime}Es=\left(H^{\prime}Es-\left(H^{\prime}Es\right)_{ med}\right)\geq 10\text{ km} \tag{2}\] \[\delta f_{b}Es=\left(f_{b}Es-\left(f_{b}Es\right)_{med}\right)/ \left(f_{b}Es\right)_{med}\geq 0.2\] (3) \[\delta f_{o}F2=\left(f_{o}F2-\left(f_{o}F2\right)_{med}\right)/ \left(f_{o}F2\right)_{med}\geq 0.1 \tag{4}\]  
where \(\Delta\) indicates absolute deviations and \(\delta\) indicates relative deviations. The satellite data, on the other hand, are collected by the ESA Swarm three-satellite constellation (Alpha, Bravo, and Charlie). Alpha and Charlie orbit side by side at an altitude of around 460 km, while Bravo orbits at 510 km. Satellite magnetic data have been analyzedusing the MASS (MAgnetic Swarm anomaly detection by Spline analysis) methodology for the magnetic data method (see, e.g., [60]). This technique is used to detect electromagnetic anomalies from Swarm magnetic field data (Level 1B, low resolution of 1 Hz) from the analysis of the three components of the geomagnetic field (X, Y, and Z) and intensity (F) for every track of each satellite (Swarm A, Swarm B, and Swarm C) recorded over the EQ preparation area [57]. The analysis consists of the determination of the first differences of the time series (dX/dt, dY/dt, dZ/dt, and dF/dt) and the removal of the long trend using a cubic spline. Moreover, it is important to evaluate the quality of the data using the quality flags provided by ESA, considering only magnetic quiet times (1 Dst \(\leq\) 20 nT and ap \(\leq\) 10 nT) and excluding polar regions (\(\pm\)50\({}^{\circ}\) geomagnetic latitudes) because they are very disturbed. After these steps, the root mean square (rms) of sliding windows of 7\({}^{\circ}\) shifting every 1.4\({}^{\circ}\) was compared with the whole root mean square of the track (RMS). When rms is greater than kt times the value of RMS, the corresponding window is classified as anomalous. For satellite magnetic data, kt is established as 2.5 [60]. This analysis covered a time period ranging from 90 days before the earthquake occurrence to 10 days after and was confined in an area comparable with the EQ preparation region [57]. Since the 1980s, NOAA satellites have continuously circled Earth's orbit, employing a shared instrument for detecting charged particles since 1998. This instrument, the Medium-Energy Proton and Electron Detector (MEPED), is integrated into NOAA satellites and features eight solid-state detectors meticulously crafted to gauge proton and electron counting rates (CRs) within the 30 keV-200 MeV range with a sampling of 2s [61].