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Research | Space Research | MIRACLE
What is MIRACLE?
The Magnetometers - Ionospheric Radars- All-sky Cameras Large Experiment (MIRACLE) is a two-dimensional instrument network constructed for mesoscale studies of auroral electrodynamics, which is maintained and operated as international collaboration under the leadership of the Geophysical Research Division of the Finnish Meteorological Institute.
The network covers an area from subauroral to polar cap latitudes over a longitude range of about two hours of local time. The various instruments have different spatial resolutions, but basically the network is designed for studies in the spatial scales from a few tens of km upward. In standard operation mode the time resolution of magnetic observations is 10 s, while the sampling rate of STARE and all-sky cameras is 20 s. MIRACLE is planned to be operative until 2004.
What can we do with MIRACLE?
The initial current system at substorm onset covers about 500 km in longitude, and pseudobreakups or other localized auroral forms are often in the scale size that can be recorded with a single all-sky camera (<600 km). Furthermore, the network can be used to monitor the motion of larger-scale structures, such as the westward traveling surge or the eastward expanding auroral bulge.
The International Solar Terrestrial Physics program studies the solar wind - magnetosphere - ionosphere interactions. Several spacecraft are in orbits that monitor the key regions in these processes: the Sun and the upstream solar wind, magnetotail processes, and auroral phenomena. MIRACLE observations support the satellite measurements by providing important information on the ionospheric boundary conditions.
Now as the global picture of the substorm evolution is rather generally accepted, ESA's Cluster II spacecraft mission has been designed especially for monitoring mesoscale processes. The configuration of four indentical spacecraft will permit the accurate determination of three-dimensional and time-varying pheonomena and will make it possible to distinguish between spatial and temporal variations. The ionospheric conjugate region of Cluster II will often be of similar size as the MIRACLE field-of-view. Thus combined MIRACLE-Cluster observations will be useful e.g when studying the polar cusps or localized flow bursts in the plasma sheet.
More information:
, tel. 358 9 1929 4637
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