This project will continue the measurement and recording of radio waves at Palmer Station, Antarctica. The principal experiment involves the monitoring of transmissions from distant very low frequency (VLF) transmitters, and using variations in the amplitude and phase of the received signal to deduce changes in the properties of the atmosphere along the great circle route between the receiver and transmitter. In particular, lightning strokes produce waves that can penetrate into the magnetosphere where they interact with energetic electrons in the van Allen radiation belts. Some of these particles can be precipitated into the upper atmosphere where they cause a sudden change in the conductivity, and therefore a perturbation in any radio wave that may be propagating through that part of the atmosphere. Thus, the monitoring of the transmitter signals can be used to map out lightning induced atmospheric disturbances that are thousands of kilometers away. The investigators will also operate equipment that will monitor natural sources of radio waves, such as the sferics produced by lightning. Stanford University and the principal investigator are leaders in research on very low frequency radio waves and their interaction with the geospace environment.
