Conjugate ionospheric perturbation during the 2017 solar eclipse

Abstract

Persistent ionospheric density depletion in conjugate lower latitudes was identified during 21 August 2017 Solar Eclipse • Conjugate depletion moved equatorward with eclipse progression and was coincident with weakening conjugate/southern equatorial ionization anomaly • Plasma pressure reduction in flux tubes shadowed by the Moon, along with disturbed northward trans-equator winds, prohibits fountain plasma southward diffusion

Tongan Volcanic Eruption Induced Global‐Scale Thermospheric Changes Observed by the GOLD Mission

“…Phase speeds around 300–400 m/s are obtained for the propagating temperature depletion structures. This is similar to the wave speeds estimated at other atmospheric altitudes for the event (Wright et al., 2022; Zhang et al., 2022).…”

“…The eruption's ionospheric signatures were observed up to 72 hr later (Zhang et al., 2022). The differential Total Electron Content (dTEC) observations used by Zhang et al.…”

Traveling Ionospheric Disturbances in the Vicinity of Storm‐Enhanced Density at Midlatitudes

“…Such constraints are eased if meridional polarization electric fields are embedded in TIDs to drive zonal plasma motion, or if the ion density is low, or if waves have short periodicities. Some of these electric fields embedded in TIDs have been recently confirmed at midlatitudes during quiet time postsunrise hours with significant TID zonal propagation for a few hours (Zhang, Erickson, Gasque, et al., 2021).…”

“…GWs near the terminator have often been observed, for example, Zhang, Erickson, Gasque, et al. (2021) identified eastward propagating electrified TIDs during postsunrise hours, and Figure 6 shows MSTIDs near the sunset terminator at 01:30 UT on 2018‐08‐26 (marked as T4). To provide further contrasts of MSTIDs between storm/substorm and non‐storm/substorm conditions, Figure 13 depicts sample non‐storm/non‐substorm MSTIDs close to the periods of the four storm events studied here.…”

Modeling Solar Eclipses at Extreme Ultra Violet Wavelengths and the Effects of Nonuniform Eclipse Shadow on the Ionosphere‐Thermosphere System

“…Interestingly, the southern crest was first slightly negative (panel c) followed by a positive bay afterward. TEC observations from the southern hemisphere reported TEC depletion at low‐latitudes (Zhang et al., 2021) and both depletion and increase at higher latitudes (He et al., 2018). These results reinforce the TEC data assimilation results indicating early reduction followed by the relative increase in the southern equatorial ionization anomaly (EIA) crest (Chen et al., 2019).…”