Observations of electric fields during two partial solar eclipses at the geomagnetic equator

Abstract. This study presents the first coordinated observations of atmospheric electric field (AEF) and ionospheric plasma drifts during the partial solar eclipses of 2 July 2019 and 14 October 2023, observed near the magnetic equator in Lima, Peru. AEF was measured using a field mill, while ionospheric drifts were obtained from radar observations at the Jicamarca Radio Observatory and local magnetometers. The two events displayed contrasting electrodynamic responses: in 2019, AEF variations were ambiguous due to meteorological fluctuations, while in 2023, clearer weather conditions revealed distinct decreases in both surface AEF and ionospheric vertical drift near maximum obscuration. These results demonstrate the variable nature of eclipse-time electrodynamics and demonstrate that simultaneous measurements of AEF and ionospheric electric field are crucial for elucidating the mechanisms of vertical coupling between atmospheric layers. Such coordinated observations provide preliminary insight into how solar and terrestrial drivers jointly modulate the near-surface electric environment, contributing to a more comprehensive understanding of atmosphere–ionosphere interactions in low-latitude regions.