Brief overview on MIRACLE research

During IMS years (IMS International Magnetospheric Study 1976-1979) an exceptionally wide magnetometer array (Scandinavian Magnetometer Array, SMA) operated in Fennoscandia. Several all-sky cameras made auroral observations in the same region and the first version of STARE started operation in 1977. The combined instrumentation were utilised in several pioneering studies on ionospheric electrodynamics of some specific auroral structures, like arcs, westward travelling surges and omega bands (e.g. Pellinen et al., 1982; Opgenoorth et al., 1983).

MIRACLE network is today's child of the IMS activities. The IMAGE network started its operation in early 1990's after the EISCAT magnetometer cross and STARE was revived from its almost twenty years' Beauty sleep in 1997. The network of FMI digital ASCs started imaging auroras in Svalbard, Lapland and Middle-Finland during years 1996-1997. Many of the IMS-results have been re-evaluated with MIRACLE data and modern data analysis methods (e.g. Amm, 1995). The concept of combined analysis of IMAGE and STARE data is still widely used in the research of magnetosphere-ionosphere coupling phenomena as observed from ground and by satellites, especially by Cluster and Double-Star.

IMAGE magnetometer network is the most widely used part of MIRACLE (c.f. IMAGE reference list) both in FMI and internationally. IMAGE observations have contributed to the research in several different areas of solar-terrestrial physics and in geomagnetic induction. The recently developed methods to deduce ionospheric equivalent currents from IMAGE data (Amm and Viljanen, 1999; Vanhamäki et al., 2003) further improve the usability of the network.

The MIRACLE ASCs have been used to study e.g. auroral streamers (Kauristie, et al.,2003) arcs (Aikio et al., 2005), and spirals (Partamies et al., 2001). Advanced machine vision methods have been utilized in the automated search routines for detecting auroral periods from the huge ASC image data base (Syrjäsuo et al., 2001). An inversion method adjusted for multiwavelength data from several cameras have been developed to facilitate the quantitative analysis of the acquired auroral intensities (Janhunen, 2001).

STARE data have been used in several studies together with IMAGE data to define the latitude-longitude distribution of ionospheric currents (horizontal and FAC) and conductivities in the radar field of view (e.g. Aksnes et al, 2005, Amm et al., Partamies et al., 2003). The reliability of the coherent scatter measurement technique in different geophysical conditions have been evaluated in comparisons studies with EISCAT incoherent scatter radar data (Uspensky et al., 2004; 2005).

IMAGE and ASC data are used also in operational space weather services Auroras Now and GIC Now! which were developed during years 2003-2004 within the Space Weather Pilot Project of the European Space Agency. An example of future efforts is the integration of the MIRACLE data server and data analysis tools to the chain of virtual geospace observatories that will be built within the ICESTAR project during 2005-2009.

References:

Aikio, A.T., Mursula, K., Buchert, S., Forme, F., Amm, O., Marklund, G., Dunlop, M., Fontaine, D., Vaivads, A., and Fazakerley, A., Temporal evolution of two auroral arcs as measured by the Cluster satellite and coordinated ground-based instruments, Ann. Geophys., in press, 2005.

Aksnes, A., Amm, O., Stadsnes, J., Ostgaard, N., Germany, G.A., Vondrak, R.R., and Sillanpää, I., 2004: Ionospheric conductances derived from satellite measurements of auroral UV and X-ray emissions, and ground-based data: A comparison. Submitted to Ann. Geophys.

Amm, O., Direct determination of the local ionospheric Hall conductance distribution from two-dimensional electric and magnetic field data: Application of the method using models of typical ionospheric electrodynamic situations, J. Geophys. Res., 100, 21473, 1995.

Amm, O. and Viljanen, A., Ionospheric disturbance magnetic field continuation from the ground to the ionosphere using spherical elementary current systems, Earth, Planets and Space, 51, 431, 1999.

Amm, O., Aksnes, A., Stadsnes, J., Ostgaard, N., Vondrak, R.R., Germany, G.A., Lu, G. and Viljanen, A., 2004: Mesoscale iono

spheric electrodynamics of omega bands determined from ground-based electromagnetic and satellite optical observations. Submitted to Ann. Geophys.

Janhunen, P., Reconstruction of electron precipitation characteristics from a set of multi-wavelength digital all-sky auroral images. J. Geophys. Res., 106, 18505-18516, 2001.

Kauristie, K., Sergeev, V.A., Amm, O., Kubyshkina, M.V., Jussila, J., Donovan, E. and Liou, K., Bursty bulk flow intrusion to the inner plasma sheet as inferred from auroral observations. J. Geophys. Res., 108, DOI 10.1029/2002JA009371, 2003.

Opgenoorth H.J., Pellinen R.J., Baumjohann, W., Nielsen, E., Marklund, G., and Eliasson, L., Three-dimensional current flow and particle precipitation in a westwrd travelling surge (observed during the Barium-GEOS rocket experiment), J. Geophys. Res., 88, 3138-3152, 1983.

Partamies, N., Amm., O., Kauristie, K., Pulkkinen, T.I., and Tanskanen, E., A pseudo-breakup observation: Localized current wedge across the postmidnight auroral oval, J. Geophys. Res., 108, 1020, doi:10.1029/2002JA009276, 2003.

Partamies, N., Kauristie, K., Pulkkinen, T.I., and Brittnacher, M., Statistical study of auroral spirals, J. Geophys. Res., 106, 15415-15428, 2001.

Pellinen, R.J., Baumjohann, W., Heikkila, W.J., Sergeev, V.A., Yahnin, A.G., Marklund, G., and Melnikov, A.O., Event study on pre-substorm phases and their relation to the energy coupling between solar wind and magnetosphere, Planet., Space Sci., 30, 371-388, 1982.

Syrjäsuo, M.T., Kauristie, K. and Pulkkinen, T.I., 2001: A search engine for auroral forms. Adv. Space Res., 28, 1611-1616.

Uspensky, M., Kustov, A., Janhunen, P., Nielsen, E., Kauristie, K., Amm, O., Pellinen, R., Opgenoorth, H. and Pirjola, R., STARE velocities: 2. Evening westward electron flow. Ann. Geophys., 22, 1077-1091, 2004.

Uspensky, M., Koustov, A., Sofieva, V., Amm, O., Kauristie, K., Schmidt, W., Nielsen, E., Pulkkinen, T., Pellinen, R., Milan, S. and Pirjola, R., 2005: Multi-pulse and double-pulse velocities of STARE echoes. Accepted for publication in Radio Sci., 2005.

Vanhamäki, H., Amm, O., and Viljanen A., 1-Dimensional upward continuation of the ground magnetic field disturbance using spherical elementary current systems, Earth, Planets, and Space, 55, 613-625, 2003.