Analysis of ionospheric disturbances using Continuous Doppler Sounding and airglow

Distinct Ionospheric perturbations such as equatorial plasma bubbles (EPB) and traveling ionospheric disturbances (TID) affect propagation of electromagnetic waves in the ionosphere. Consequently, electromagnetic waves can be used for their investigation. However, the ionospheric perturbations can also be monitored and analysed optically, using airglow emissions of OI red line (630 nm) because the intensity of this emission depends on the electron density and composition of the thermosphere, which changes with height.

     Simultaneous observations of EPBs and TIDs over Northern Argentina by airglow imager and Continuous Doppler Sounding (CDS) are presented. The EPBs propagated roughly eastwards as expected, whereas the large scale TIDs detected by both instruments propagated roughly north-westward. The TIDs of shorter periods/wavelengths are mostly observed only by CDS. A likely explanation is that the positive and negative phases of waves with shorter wavelengths are cancelled during integration along the line of sight in a relatively thick OI 630 nm emission layer. Selected examples and their propagation analysis is presented.