Relatively Intense Daytime GNSS Amplitude Scintillations at Middle Latitude Linked With Multi‐Layered Strong Es Structures

Abstract Intense Global Navigation Satellite System (GNSS) amplitude scintillations usually occur in nighttime at low latitudes due to ionospheric plasma bubble irregularities. During daytime at middle latitudes, previous studies found that the sporadic E (Es) layer could lead to GNSS amplitude scintillations, which however, is relatively weak, for example, S4 generally below 0.3. In this study, relatively intense daytime GNSS amplitude scintillations with S4 up to ∼0.5 were observed linked with strong Es with a top frequency up to 20 MHz. The strong Es layer, manifested as pulse‐like disturbances in total electron content time series and narrow‐band‐like structures elongating ∼2,000 km in the horizontal plane, caused short‐duration signal fading up to ∼3 dB in the raw GNSS data, thus resulting in the relatively intense scintillations. Further analysis found that the strong Es was possibly multi‐layered in the vertical direction, which may complicate radio‐wave propagation between multiple layers and further enhance signal fading and scintillation.