The Penetration Electric Fields During the 10 May 2024 Superstorm Observed by ISRs Over Sanya and Jicamarca

Abstract

We used the incoherent scatter radar observations at Sanya (18.3°N, 109.6°E) and Jicamarca (11.9°S, 76.9°W) to analyze the day-night difference of penetration electric fields during the 10 May 2024 superstorm. The dawn-dusk electric field penetrated into the night ionosphere more efficiency, and the night-to-day penetration ratio was ∼2. Specially, the zonal electric field became westward in the post-midnight, while it did not change significantly in the afternoon in response to the IMF-Bz southward turning at 17:45–18:25 UT and 19:30–22:30 UT. These indicated that the penetration electric field was rapidly and long-lastingly canceled by shielding electric field, which had rarely been reported. In this period, the enhanced Region-2 field-aligned current shifted to mid-latitudes and the enhanced sunward convection penetrated to low-latitudes, indicating the shielding layer might closely move to Earth. Under this condition, the shielding layer would promptly reconfigure to cancel the penetration electric field and lead to the perfect shielding.