The auroral oval is an annular ring around each geomagnetic pole where aurora are
most likely to occur. The aurora are caused by the excitation of particles from
the Sun spiralling in the geomagnetic field near the poles resulting in the release of
energy in different forms, including light. The above model attempts to predict the
location of the auroral oval around the geomagnetic south pole. Images and reports
of auroral displays are often reported to IPS. A listing of previous aurora observation
reports is available here.
Hourly Riometer Absoprtion Values
Last updated 05 Jul 2008 19:40 UT
| Sat Jul 5 19:39:54 GMT 2008
Macquarie Island 0.0 dB
Casey -0.0 dB
Davis 0.0 dB
Mawson 0.4 dB
|
|
A riometer is a "relative ionospheric opacity metre" which measures the amount of
absorption of galactic radio noise as this signal passes through the Earths ionosphere.
During geomagnetic storm activity, auroral activity can increase, increasing the level
of ionospheric absorption of this natural radio signal, indicating possible
disruptons to polar and transpolar HF radio communication, if the radio wave has a reflection
point in the auroral zone. Absorption can also increase
dramatically for up to several days, in polar regions, due to solar proton events,
following strong solar flare activity.
Antarctic Riometer time series plot
Geophysical