The Study of Daytime Ionospheric E‐Region Radar Echoes Simultaneously Observed by Qujing VHF Radar and Multi‐Ionosondes

Abstract

In this work, the daytime E‐region field‐aligned irregularities (FAIs) observed by the Qujing (geographic 25.64°N, 103.70°E) Very High Frequency coherent backscatter radar was reported. The range spread and enhanced sporadic‐E layer (Es) during the same period of the unusual radar echoes were separately observed by two ionosondes located at the Huize and Qujing. The Huize (geographic 26.51°N, 103.61°E) ionosonde was roughly located underneath the radar scattering volume which measured enhanced and range spread Es layer during this period of the unusual radar echoes, indicating that the daytime E‐region FAIs were closely related to the localized density gradient that embedded within the coordinated Es layer. Fengyun‐4A (FY‐4A) satellite data show that a strong convective activity accompanied by gravity waves occurred near the radar scattering volume region. As a result, we proposed that the gravity waves driven by the convective activity in the lower atmosphere can modulate the Es layers and then generate the daytime FAIs through the polarization process.

High-Resolution Observation of Ionospheric E-Layer Irregularities Using Multi-Frequency Range Imaging Technology

“…The multilayered FAI structure at night may be caused by the gradient-drift instability acting on multiple ionized density-gradient layers formed by tides or gravity waves. Specifically, the multiple Es layer indicates the development of an electron density gradient and strong spatial structuring in the electron density, and the ambient electric field in the Es layers could excite the stronger FAIs around the local Es altitude [48]. This example demonstrates that the spatial resolution of the E-region FAIs is improved by the RIM technique and is suitable for the observation of multiple layers of E-region FAIs.…”

Controlling Factors of Artificial Irregularities Triggered by Chemical Release at Low Latitude Ionosphere

“…For realistic irregularities, their structures and strengths are usually obtained by radio and optical diagnostic systems, such as beacons, incoherent scatter radars, glow imagers and others (Häggström et al., 1990; Igarashi et al., 1982; Wei et al., 2021; Zhang et al., 2016; Zhu et al., 2022). While in simulations in the literature, the evolution process, that is, the rising, penetration, bifurcation of the stimulated plasma bubble is usually confirmed by patterns of the plasma distribution.…”