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A sodium Doppler lidar system with three‐directional measurements of sodium density, atmospheric wind field, and temperature was established at Zhongshan (69.4°S, 76.4°E), Antarctica. On November 14, 2019, a sporadic sodium layer (SSL) was observed at an altitude range of 93–103 km. The temporal/spatial sodium density variations of this SSL are associated with a strong sporadic E (Es) layer at nearly the same height, which is modulated by the convective electric field. By considering the structures and the time lags of the SSL's growth at three positions, the SSL appears to have a horizontal advection in an approximately westward direction with a velocity of the order of 80 m/s. This is consistent with the zonal wind velocity derived from the lidar system itself. The temporal/spatial sodium density variations strongly indicate that the formation and perturbation of SSLs are related to the evolution of ES layers due to varied electric fields and atmospheric gravity waves, while it is advected by the horizontal wind.

Geosynchronous orbit (GEO, ∼6.6 Earth's radii) is located in the region of the outer radiation. At GEO, hundreds of satellites operate in this region, during the main phase of a high-energy storm, the relativistic electrons rise in count from 10 up to 10 5 (electrons Sr −1 s −1 ) (Sakaguchi et al., 2013). The deep-dielectric charging by relativistic electrons could damage satellites at GEO and poses a risk for space security (Wrenn et al., 2002). According to the statistics of faults, more than 50% failure rate of GEO satellites were caused by the accumulation of high-energy charged particles from March 1992 to April 1994(He et al., 2013. Therefore, the prediction of >2 MeV electron fluxes has important scientific and application value, which is the necessary measure to be taken in advance to reduce the harm of relativistic electrons to space instruments.The sudden acceleration of relativistic electrons is responsible for the increased fluxes. Summers et al. (1998) proposed a model which account for the observed variations in the flux and pitch angle distribution of relativistic electrons during geomagnetic storms. Presently, two types of acceleration mechanisms of relativistic electrons have been proposed: the mechanism of radial diffusion (Li et al., 2001), and the local interaction of wave-particles (Simms et al., 2018). Based on the radial diffusion mechanism, Li et al. (2001) proposed a radial diffusion model that took solar wind parameters and the interplanetary magnetic field as input parameters to predict the relativistic

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The Extremely Low Frequency (ELF) and VLF waves, with frequencies typically ranging from 300 Hz to 30 kHz, can be categorized as the naturally occurring waves and artificial emissions (e.g., Cohen et al., 2010;Ni et al., 2022). Lightning discharges and man-made VLF transmitters are the two dominant sources of ELF/ VLF waves that repetitively reflect and propagate within the Earth-ionosphere Waveguide (EIWG) (e.g., Barr et al., 2000;Silber & Price, 2016). With wavelengths of 10-1000 km, these waves are well bounded by the terrestrial surface and the lower ionosphere, and can thus propagate thousands of kilometers with relatively low attenuation (∼2 dB/Mm) (e.g., Davies, 1990;Sasmal, 2018). As such, the propagation of ELF/VLF waves is primarily influenced by the variation of the lower and upper boundaries of EIWG, especially a region that Abstract A Very Low Frequency (VLF) wave detection system has been designed at Wuhan University (WHU) and recently deployed by the Polar Research Institute of China at the Chinese Great Wall station (GWS, 62.22°S, 58.96°W) in Antarctica. With a dynamic range of ∼110 dB and timing accuracy of ∼100 ns, this detection system can provide observational data with a resolution that can facilitate space physics and space weather studies. This paper presents the first results of the wave measurements by the WHU VLF wave detection system at GWS to verify the performance of the system. With the routine operation for 3 months, the system can acquire the dynamic changes of the wave amplitudes and phases of various ground-based VLF transmitter signals emitted in both North America and Europe. A preliminary analysis indicates that the properties of the VLF transmitter signals observed at GWS during the X-class solar flare events are consistent with previous studies. As the HWU-GWS path crosses the South Atlantic Anomaly region, the observations also imply a good connection in space and time between the VLF wave disturbances and the lower ionosphere variation potentially caused by magnetospheric electron precipitation during the geomagnetic storm period. It is therefore well expected that the acquisition of VLF wave data at GWS, in combination with datasets from other instruments, can be beneficial for space weather studies related to the radiation belt dynamics, terrestrial lightning discharge, whistler wave propagation, and the lower ionosphere disturbance, etc., in the polar region. Plain Language Summary Considering the good coverage and quiet electromagnetic environment,Antarctica is an ideal place for plasma wave measurements. Various stations have been established in Antarctica, of which Palmer station is particularly noteworthy and has historically provided valuable VLF data for atmospheric, ionospheric, and magnetospheric studies. An Extremely Low Frequency/Very Low Frequency (VLF) wave detection system has been designed by Wuhan University and recently set up at Great Wall station (GWS) in Antarctica. This device can effectively record VLF signals with frequencies of 1-50 kHz, including...