Storm‑Time Variability of GNSS‑Derived Ionospheric VTEC over East Africa during Four Major Geomagnetic Storms of Solar Cycle 24 - Muniafu, Wilberforce; Uluma, Edward; Lomotey, Solomon Otoo; Tilahun, Atirsaw Muluye; Mefe, Moses; Muriithi, Joseph Kagotho; Omondi, George; Ndinya, Boniface (Earth and Planetary Science, 2026)