Responses of Ionospheric Peak Density and Height to Magnetospheric Forcing During a 30-day Quiet Period in Solar Minimum

Magnetospheric forcing during geomagnetically ‘quiet’ periods is generally assumed to have little impact on the low and mid latitudes ionosphere, especially during solar minimum. However, recent observational evidence suggests that geomagnetic forcing can exert a measurable impact on the global ionosphere even during geomagnetically quiet times. In this study, the Whole Atmosphere Community Climate Model eXtended is employed to investigate how magnetospheric forcing affects the 30-day average of ionospheric F2-region peak electron density (NmF2) and height (HmF2) during a geomagnetically quiet period (average Kp 1.67). Four 5-member ensemble simulations were conducted with different geomagnetic forcing: (1) no geomagnetic disturbances, (2) real Kp, (3) a constant low Kp of 1.67, and (4) a constant moderate Kp of 3.33, all under the same solar minimum condition with a constant F10.7 of 70 sfu. These ensemble runs were generated by introducing small neutral temperature perturbations. The results reveal that quiet-time magnetospheric forcing alters the 30-day mean NmF2 by 20–60% at low and mid latitudes. Daytime HmF2 rises by 20–50 km near the equatorial ionization anomaly crests but decreases by 20–30 km near the dip equator around local sunset. These variations are primarily driven by changes in neutral composition, winds, and plasma vertical E×B drifts. These findings demonstrate that magnetospheric forcing during quiet periods can influence ionospheric NmF2 substantially. Our results highlight the need to account for the effects of quiet-time magnetospheric forcing in space weather forecasts and scientific research.