Oulu Cosmic Ray Station

Cosmic ray measurements in Oulu started in 1964 in a wooden barrack with a standard 9-NM-64 neutron monitor (NM) consisting of three units each of three counters. The monitor was moved to its present site (65.05°N, 25.47°E) in September 1973. Because of its northern latitude, the building has a pyramid shaped steep roof to prevent snow from accumulating on it. The Oulu station is a part of the World Network of Neutrom Monitors.

The station was managed by Hannu Kananen (deceased in March 2000) since the very beginning till 31/12/1999. Since 01/01/2000 the Station is managed by Ilya Usoskin. The stations is a part of the Oulu unit of the Sodankylä Geophysical Observatory (SGO), which is part of the Oulu University.

The counts of the neutron monitor are accumulated over 1-minute and 1-hour intervals. A separated data collecting system (built by the University of Turku) with 10 seconds  recording time is also available. The data are regularly sent to World Data Centers (A, B, C2) and other scientist (see Kananen et al., 1991). Cosmic rays are also studied in Oulu (see research in Oulu).

The full database (since 1964) is available online now.

Description (pdf-file) of the Database is here.

Publications using the Oulu NM data

Reference: Kananen, H., P.J. Tanskanen, L.C. Gentile, M.A. Shea and D.F. Smart, A quarter of a century of relativistic solar cosmic ray events recorded by the Oulu neutron monitor, Proc. 22nd  ICRC, 3, 145-148, 1991.