SGO Node

Location (town, country): Sodankylä, Finland

Web site:

Description of the infrastructure:

The Finnish pulsation magnetometer chain (PuMa) is operated by SGO since 1999 after observatory of University of Oulu was joined to Sodankyla Geophysical Observatory. The chain includes six stations in Finland from 60.5°N to 69°N (from L-values 3.4 to 6.1) namely KIL, IVA, SOD, ROV, OUL and NUR. Pulsation magnetometers are completely designed and built in-house and thus internationally unique. The data from Sodankylä station has been available since 1971.

The Kilpisjärvi Atmospheric Imaging Receiver Array (KAIRA) is a dual array of omnidirectional VHF radio antennas located near Kilpisjärvi, Finland. It is operated by the Sodankylä Geophysical Observatory. It makes extensive use of the proven LOFAR antenna and digital signal-processing hardware, and can act as a stand-alone passive receiver, as a receiver for the European Incoherent Scatter (EISCAT) very high frequency (VHF) incoherent scatter radar in Tromsø, or for use in conjunction with other Fenno-Scandinavian VHF experiments.

Riometer measurements started 1965 and all Finnish stations since 1970. The Finnish Riometer Chain maintained by SGO includes observation sites in Kilpisjärvi, Ivalo, Sodankylä, Rovaniemi, Oulu, Jyväskylä and Nurmijärvi.

Services currently offered by the infrastructure:

Kilpisjärvi station of PuMa network has been relocated with new 24bit system with 250Hz samping in Sep 2015 nearby the IRIS riometer and runs as two-component station. Total power spectrum from horizontal components and polarization properties are presented in the quicklook pages. The old station was closed in November 2015. The new station runs with new version of the instrument having better SNR than the other stations. All the stations will be upgraded in near future. Riometers provide data by request.

KAIRA observes continuously, 24-hours a day and all-year-round. The default observation mode is handled by KBT (KAIRA Background Task), unless a special experiment or campaign is scheduled. Unlike multibeam riometers, which form discrete beams on the sky, the interferometric technique permits all-sky sampling of incoming cosmic radio noise emissions resulting in a spatially-continuous radiogram of the entire sky. The map of the received power at each time may then be compared to the equivalent map from a “quiet day”, allowing the morphology of ionospheric absorption of cosmic radio noise to be ascertained. KAIRA was used to carry out the first interferometric riometry measurements in late 2013, producing all-sky absorption maps of space weather related ionization in the D region.

New areas opening to users:

  • High latitude ionosphere and thermosphere physics experiments and investigations.
  • Geomagnetic pulsation analysis, identification of Pc5 oval and comparison to the location of visual auroral observations by all-sky cameras at SGO.
  • Comparison of seasonal variability of substorm location and dynamics to the Pc5 and visual ovals.
  • Computing pulsation power in different locations in the polar regions and analysis of the local inhomogenities.