School of Chemistry & Physics

Dr. Judy Stephenson

Researcher and data manager

Dr Judy Stephenson is a member of the Sanae HF radar experiment team which is the South African part of the international group HF radar network known as SuperDARN.

Her job entails research with the Sanae HF radar and other SuperDARN radar data and supervising postgraduate students. This instrument provides a ‘window into space’ and, as such, her field of specialization is the magnetosphere and its interaction with the solar wind and neutral atmosphere.

In addition, she manages the data from the Sanae HF radar and is responsible for the installation and maintenance of the radar software which runs on LINUX servers.

Research interests

  • Space Weather
  • Magnetospheric Physics

 

Research profiles

Research overview

Space weather is a topic that embraces all physical process that control the transfer of energy from the Sun and its solar wind into the Earth’s magnetosphere (space surrounding the Earth governed by the Earth’s intrinsic magnetic field) and the transport of energy and plasma through the magnetosphere-ionosphere system where it can have profound effects on our modern infrastructure. The beauty of the aurora (formed by energetic particles from the Sun being funnelled and accelerated into the atmosphere by the Earth’s magnetic field) belies its dangers to our modern technologically dependent world. Research into space weather helps their Group to mitigate these risks by providing the knowledge to make realistic preparations. In particular, Judy is data manager and researcher of the SANAE HF radar which is part of the international network of similar radars known as SuperDARN (vt.superdarn.org). SuperDARN radars provide a “window into space” and have coverage of a significant portion of high and mid-latitudes of the globe. This network has won awards from NASA and RAS for its contribution to space weather.

Current projects

Travelling Ionospheric Disturbances (TIDs). TIDs are oscillatory disturbances in the electron concentration of the ionosphere and may have their causes from the neutral atmosphere below e.g. gravity waves or from within the ionosphere itself e.g. strong currents caused by increased solar activity. TIDs play an important role in energy exchange (and thus global circulation patterns) between the ionosphere and the neutral atmosphere. Ultra Low Frequency (ULF) pulsations. These pulsations (in the frequency range 1-30 mHz) are prevalent in space plasmas and are of more than one type. They are important transporters of energy and can also be used as a diagnostic tool to indirectly determine other plasma parameters of interest.

Associations/ Affiliations

South African National Space Agency

Collaborators

  • SuperDARN radar network

Media

Aurora Australis over the SANAE IV base, Antarctica

An engineer performing maintenance on an antenna of the SANAE HF radar(part of SuperDARN network)