Deployment and initial observations of the Wuhan University very low frequency (WHU VLF) wave detection system at the Great Wall Station in Antarctica

Abstract

A system for the detection of very low frequency (VLF) electromagnetic waves has been developed by Wuhan University (WHU) with the Polar Research Institute of China (PRIC), and has been successfully deployed by PRIC at the Great Wall Station (GWS, 62.22°S, 58.96°W) in Antarctica, as part of the Phase II of Chinese Meridian Project. The system has a dynamic range of ~110 dB and a timing accuracy of ~100 ns, and hence can provide observational data at sufficient resolution to contribute to space physics and space weather research. This paper reports initial measurements of the WHU VLF (Meridian Project-Phase II ID：OCHCH_WHWM01) wave detection system at GWS, to demonstrate performance of the system. Data from nearly one year of routine operation indicate that the system is effective in recording the dynamic change of ground-based VLF transmitter signals from North America and Europe. The characteristics of VLF transmitter signals observed at GWS during X-class solar flares are consistent with results from previous studies. The VLF data exhibited a good correlation in space and time with measurements of magnetospheric electron deposition during geomagnetic storms, as detected in the south Atlantic anomaly (SAA) region. The WHU VLF system additionally provides data on the wide-band whistler waves as excited by lightning discharge, the spectrum of which exhibits a distinctive dispersion structure. The unique position of GWS in Antarctica provides the opportunity to obtain observational data on VLF waves which can be used to investigate multiple aspects of space physics, including the propagation of whistler waves in polar regions, lower ionosphere disturbance, lightning discharge, and radiation belt electron precipitation from the radiation belts. These measurements are of critical importance in monitoring near-Earth space weather.

Keywords

• whistler wave monitoring equipment
• antarctic great wall station
• space weather
• vlf wave propagation
• chinese meridian project