Summary
A UMLCAR ( University of Massachusetts Lowell, Centre for Atmospheric Research) Digital Ionosonde (DPS-4) has operated at the Australian Antarctic polar cap station Casey (80.8oS geomagnetic latitude) since early 1993, primarily to study the dynamics of the southern polar cap ionosphere. To gain a better understanding of the ionospheric motions involved and to identify dynamical features, animated data displays have been developed using ionospheric drift and ionogram data combined together with other geophysical data sets. These displays generally show ionospheric skymaps (echo locations), drift velocities and Doppler ionograms (vertical profiles), produced with a time resolution of up to a frame every three minutes. Static displays of other geophysical data sets (e.g. Total Electron Content (TEC) from Global Positioning System (GPS) satellites or Interplanetary Magnetic Field (IMF) measurements) can be incorporated into the animations. Ionospheric changes can then be viewed frame-by-frame using commercial animation software. The displays provide a simple means of displaying large amounts of data and identifying, for example, drifting polar patches, or the response of ionospheric drift to changes in the IMF. Since the ionosonde takes measurements throughout the bottomside ionosphere, different height regions (e.g. E and F) can be examined independently or compared directly. Doppler and directional information featured in the animations provide a powerful technique for studying the evolution of ionospheric phenomena such as polar patches. Some of the applications of the ‘ionomovie’ animations in ionospheric research will be demonstrated.