Ionosphere Research Unit

Research is lead by Professor Anita Aikio.

The group studies ionospheric physics and geospace environment by utilizing different ground-based and satellite measurements. One of the most important research infrastructures is the EISCAT (European Incoherent Scatter) radar facility. The scientific EISCAT Association is a collaborative venture between United Kingdom, Norway, Sweden, Finland, Japan and China. The current Associate countries are France, Russia and Ukraine.

The organization was founded in 1975, and currently it runs two radar systems investigating the Earth's ionosphere. The radio signal of the UHF radar is transmitted from Tromsø (Norway), and the reflected signal is measured in Kiruna (Sweden), Sodankylä (Finland), and in Tromsø. The transmitter/receiver system of the VHF radar is located in Tromsø only. With these radars, researchers can study the Earth's ionosphere from altitudes of few tens of kilometers up to close 2000 kilometers. The incoherent scatter method used makes it possible to measure ionospheric electron density, electron and ion temperatures, ion drift speed, and collision frequencies between particles. The three point geometry of the ULF radar allows also the calculation of the ionospheric electric fields from the ion drift. Other derivable parameters are, e.g., ionospheric currents and the characteristics of the precipitating auroral particles.

Oulu group

With the 6 % share of the system, Finnish researchers can use EISCAT facility for 50 hours per year. For example, the Space Physics Group of Oulu has organized several measurement campaigns with optical auroral instrumentation. Recently ground based VLF measurements and tomographical electron content measurements of the ionosphere have supported EISCAT in these campaigns, and ionospheric heating campaigns have also been organized. Together with the Sodankylä Geophysical Observatory, Oulu is responsible for the scientific work done in Finland with this data. This activity has lead, for example, to Tuomo Nygrén's text book "Introduction to incoherent scatter measurements".

EISCAT related publications by the Oulu group

Since most of the EISCAT papers with Finnish contribution include also a co-author from the Oulu group, you can use the list of the Finnish EISCAT publications provided in here. An historical account (in Finnish) of the Finnish research is available here.

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Last updated: 14.2.2017