Equatorial to Low-latitude IT Dynamics during Geomagnetic Disturbances

In the equatorial and low latitude ionosphere, the equatorial ionization anomaly (EIA) is the most striking large-scale phenomenon. Embedded within EIA are low-density smaller-scale structures, i.e., the equatorial plasma bubbles (EPBs), which occur preferentially over the post-sunset local times. EPBs are known to host ionospheric irregularities that can cause severe satellite signal scintillation and even signal loss of lock, thereby affecting communication and navigation. The overarching science goal of this project to deepen our understanding of various factors affecting the EIA and EPB growth during geomagnetic disturbances and their contributions to day-to-day and longitudinal variability using a comprehensive observational instrument suite and state-of-the-art numerical models [Jin et al., 2018, Aa et al., 2018a, 2018b, 2019, 2020, Jin et al., 2021].

Example of EIA and EPB from GPS TEC and GOLD. In situ density observations from SWARM are shown on the right. (From Aa, E., Zou, S., et al. 2019, “Coordinated ground-based and space-based observations of equatorial plasma bubbles”)

Backscattered echo signal-to-noise ratio in the zonal-vertical plane between 13:09 and 14:45 UT with a time step of 12 min on 8 September 2017 showing the freshly generated type of the field-aligned irregularities. From Jin et al., 2018.