## 4 Discussion  
In this study, a spatiotemporal investigation of ionospheric TEC, Ne, Te, foF2, and hmF2 fluctuations preceding the 2015 and 2023 earthquakes in Afghanistan was conducted, indicating significant abnormalities and trends (summarized in Tables 1 and 2). The TEC values from the GIM and GPS ground stations differed significantly from the expected background levels, indicating the presence of ionospheric disturbances. The GIM-TEC anomalies observed on 18 October 2015 and 13 October 2023 followed a semi-global pattern. These anomalies coincided with geomagnetic and solar calm days, implying the presence of additional contributing forces, which could possibly be the  
Figure 11: NI135 ionogram from the DID based on the 26 October 2015 and 7, 11, and 15 October 2023 reflectivity, illustrating frequency versus trip time around 2–4 min before each earthquake, where the Y-axis is height (km) and x-axis is frequency (MHz). Red: O-polarization echoes (vertical); green: X-polarization echoes. Real-time EDP using O-traces (thin black lines) and computed bottom-side EDP (black line with uncertainty bars) [56]. previous days' geomagnetic activities, climate variations such as air pressure currents, human activities, radiofrequency interferences, or electromagnetic emissions causing global-scale positive anomalies. The simultaneous abnormalities detected in ionospheric plasma and critical frequency, both in terms of spatial and temporal aspects, highlight the atypical nature of these specific days, potentially implying a link to seismic activity. The Ne and Te parameters also showed noticeable variations before the earthquakes, illustrating the ionosphere's dynamic reaction to seismic activity. The foF2 and ionogram results exhibit fluctuations in the ionospheric height and critical frequency fof2. Furthermore, the lithosphere-atmosphere-ionosphere interaction concept proposes that electric field fluctuations due to radon gas release or gravity waves caused by tectonic stresses might propagate upward and effect the ionosphere. These electric field disturbances can alter plasma density (Ne), electron temperature (Te), and the F2 layer's critical frequency (foF2). Without exception, ionospheric disturbances have regularly been measured before earthquakes. According to studies, these pre-seismic TEC, Ne, Te, and foF2 anomalies might begin 20-15 days in advance and last until a few minutes before the earthquakes, which also suggests the benefit of LAI coupling [57; 58; 59]. The fundamental mechanism most likely includes rock stress causing electromagnetic emissions and energy transfer between Earth's geophysical layers [4]. Multiple data sources confirm a compelling link between ionospheric disturbances and seismic activity, bolstering the notion that these anomalies may foreshadow earthquakes [60]. For instance, [PERSON] reinforced this by demonstrating abnormalities in the ionospheric quasi-static electric field during seismic events, implying a possible link between these disturbances and earthquakes [61]. [PERSON] recognized the potential of ionospheric changes as precursors to seismic occurrences, notwithstanding the need for further research [62]. These investigations reinforce the case for examining the relationship between ionospheric disturbances and seismic activity. To demonstrate a causal relationship between the detected anomalies and earthquakes, it is critical to examine ionospheric fluctuations caused by upper atmospheric events such as thunderstorms, which are characterized by heavy clouds, intense rainfall, and lightning. Weather conditions during seismic occurrences were tracked using data from EUMETSAT [[[https://www.eumetsat.int/](https://www.eumetsat.int/)]([https://www.eumetsat.int/](https://www.eumetsat.int/))] and Ventusky. The unusual days and times were compared to local weather conditions, cloud activity, and total rainfall in the earthquake preparation area.