Very Low Frequency Radio Observations of Lightning Discharges at Scott Base
The WWLLN Very Low Frequency (VLF) Radio Sensor was installed at Scott Base in November 2015 by Dr. James Brundell and Ms. Emma Douma as part of Antarctica New Zealand Event K060-1516-A. The sensor measures the electric field in the Very Low Frequency radio range (~500 Hz-50 kHz) and passes it to a PC which processes the data for the experiments.
The antenna is located behind the Hatherton lab. It was installed due to increasing manmade electromagnetic noise levels in the "quiet zone" at Arrival Heights. The observations from this antenna are now the primary WWLLN feed from Ross Island, the Arrival Height's magnetic field antenna is now a backup. WWLLN, uses the VLF feed but processes it to detect the radio-wave pulses from lightning. WWLLN observations are sent to a central processing computer to determine the time and location of lightning pulses all over the globe. The World Wide Lightning Location Network (WWLLN) is an experimental Very Low Frequency (VLF) network of sensors being developed through collaborations with research institutions across the globe. The network exploits the considerable electromagnetic power radiated by lightning as "sferics" present in the VLF band. By combining radio-pulse observations from at least 5 stations, the WWLLN central processing computers can determine the location of the original lightning discharge. As the radio-pulse observations are immediately sent back across the internet to the central processing computers locations are generated within ~10 s of the discharge, and thus near real time. There are currently about 70 active VLF receiving stations operating in the VLF World-Wide Lightning Location Network, including the Scott Base measurements. WWLLN observations are continuously transmitted to one of the WWLLN primary servers, in this case flash.ess.washington.edu at the University of Washington, Seattle, USA.