摘要：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.
