National Institude of Information and Communications Technology has been observing the absorption of cosmic radio noise with a standard riometer (relative ionospheric opacity meter) at 30 MHz at Syowa Station,Antarctica since February 1966.
The combined data plots also contain geomagnetic field provided by National Institute of Polar Research.
Comments on this report and requests for additional copies are welcome and should be sent to the following address:
Applied Research and Standards Department
National Institute of Information and Communications Technology (NICT)
2-1, Nukui-Kitamachi 4-chome, Koganei-shi
Tokyo 184-8795, Japan
E-mail address: syo_iono(at)ml.nict.go.jp