2002-2003 Science Planning Summary

Aeronomy & Astrophysics

Dr. Vladimir Papitashvili
Program Manager

AO-108-O

NSF/OPP 00-93381
Station: South Pole Station
RPSC POC: Paul Sullivan
Research Site(s): South Pole Station

A VLF beacon transmitter at South Pole (2001-2004)
Dr. Umran S. Inan
Stanford University
Department of Electrical Engineering
inan@nova.stanford.edu
http://www-star.stanford.edu/~vlf

Deploying Team Members: Jeffrey Chang . Robert Moore . Evans Paschal
Research Objectives: Relativistic electrons -- measured at geosynchronous orbit with energies of more than 300 kiloelectron volts -- appear to fluctuate in response to substorm and solar activity. During such events, these highly energetic electrons can penetrate as low as 30 to 40 kilometers above the Earth's surface. At that altitude, they can wreak havoc in the atmosphere, ionizing chemical species, creating X-rays, and perhaps influencing the chemistry that produces ozone.

This is a 3-year project to establish and operate a very-low-frequency (VLF) beacon transmitter at South Pole to measure solar effects on the mesosphere and lower ionosphere. The extent of relativistic electron precipitation can be calculated from variations in amplitude and phase of the VLF signals at different antarctic stations. The transmitter will also produce other data as well - on solar proton events, relativistic electron precipitation from Earth's outer radiation belts, and on the Joule heating components of high-latitude/ polar-cap magnetosphere/ionosphere coupling processes.

VLF data from the South Pole beacon provides a valuable complement to two other efforts: The southern hemisphere coherent HF radar network, Super4 Dual Auroral Network (SUPERDARN), and the Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX), ongoing satellite-based measurements of trapped and precipitating high-energy electrons at high and low altitudes.


Field Season Overview:
This field season is the project's second year. Assembly and construction of the transmitter will begin in early December 2002. One team member will remain in residence at South Pole Station for the duration of the summer season to oversee construction, ensure the structure's scientific integrity, and prepare the electronic components of the system for final installation in January, 2003. Two team members will travel to South Pole Station for three-weeks in December to complete the installation of electronic components controlling the beacon system, to perform system tests, and to make comprehensive diagnostic measurements.

The South Pole science technician will assist the researchers during the austral summer and will monitor the equipment and perform routine maintenance during the winter.