Abstract
We have compiled archived geomagnetic observations from the Helsinki magnetic observatory as well as visual sightings of auroral occurrence in Finland. The magnetic database comprises about 2 000 000 observations of H- and D-components measured during 1844–1909 with time resolution of 10 min to 1 h. In addition, magnetic observations carried out in the First and Second Polar Years in Finland have been recompiled. Magnetic activity indices (three-hour K-and daily Ak-figures) have been derived from the magnetic observations. Comparisons between the Finnish indices and simultaneous global aa-index (starting in 1868) show a good mutual correlation. The Helsinki activity index series can be used as a (pseudo) extension of the aa-index series for about two solar cycles 1844d –1868. On the annual level the correlation coefficient is about 0.9 during the overlapped time interval 1868–1897. The auroral database consists of about 20 000 single observations observed in Finland since the year 1748. The database of visual auroras has been completed by auroral occurrence (AO) index data derived from the Finnish all-sky camera recordings during 1973 –1997 at several sites in Lapland. The AO-index reveals both spatial and temporal variations of auroras from diurnal to solar cycle time scales in different space weather conditions.
Similar content being viewed by others
References
Beckman, O.: 1999, Bull. Scient. Instrum. Soc. 61, 15.
Cawood, J.: 1977, Ann. Sci. 34, 551.
Cawood, J.: 1979, ISIS 70, 493.
De Mairan, J. J.: 1733, Impremie Royale, Paris.
Fritz, H.: 1873, Gerold, Wien, 255 pp.
Gnevyshev, G. N.: 1967, Solar Phys. 1, 107.
Hällström, G. G.: 1847, Acta Soc. Sci. Fenn. 2, 363.
Legrand, J.-P. and Simon, P. A.: 1987, Ann. Geophys. 3, 161.
Lockwood, M., Stamper, R., and Wild, M. N.: 1999, Nature 399, 437.
Malin, S. R. C. and Barraclough, D. R.: 1991, Q. J. R. Astr. Soc. 32, 279.
Menvielle, M. and Berthelier, A.: 1991, Rev. Geophys. 29, 413.
Menvielle, M., Papitashvili, N., Häkkinen, L., and Sucksdorff, C.: 1995, Geophys. J. Int. 123, 866.
Nevanlinna, H.: 1995, J. Geomagn. Geoelectr. 47, 953.
Nevanlinna, H.: 1997, J. Geomagn. Geoelectr. 49, 1209.
Nevanlinna, H.: 1999, Geophysica 35, 15.
Nevanlinna, H.: 2004, Ann. Geophys. 21, 1691.
Nevanlinna, H. and Pulkkinen, T.: 2001, J. Geophys. Res. 106, 8109.
Pulkkinen, T. I., Nevanlinna, H., Pulkkinen, P. J., and Lockwood, M.: 2001, Space Sci. Rev. 95, 625.
Silverman, S. M.: 1992, Rev. Geophys. 30, 333.
Simojoki, H.: 1978, Societas Scientarium Fennica, Helsinki, 157 pp.
Stern, D. P.: 2002, Rev. Geophys. 40, doi.10.1029/2000RG000097.
Syrjäsuo, M.: 2001, Finn. Met. Instrum. Contrib. 32.
Usoskin, I. G. and Mursula, K.: 2003, Solar Phys. 218, 319.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Nevanlinna, H. Historical Space Climate Data from Finland: Compilation and Analysis. Sol Phys 224, 395–405 (2004). https://doi.org/10.1007/s11207-005-3749-8
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s11207-005-3749-8