The First Two Years of IMAGE

J. L. Burch 


The Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) is the first
satellite mission that is dedicated to imaging the EarthÕs magnetosphere. Using
advanced multispectral imaging techniques along with omnidirectional radio
sounding, IMAGE has provided the first glimpses into the global structure and
behavior of plasmas in the inner magnetosphere. Scientific results from the
two-year prime mission include the confirmation of the theory of plasmaspheric
tails and the discovery of several new and unpredicted features of the
plasmasphere. Neutral-atom imaging has shown how the ring current develops
during magnetic storms and how ionospheric ions are injected into the ring
current during substorms. The first global imaging of proton auroras has allowed
the identification of the ionospheric footprint of the polar cusp and its
response to changes in the interplanetary magnetic field. Detached subauroral
proton arcs have been found to appear in the afternoon sector following
south-north and east-west rotations of the IMF. Low-energy neutral atom imaging
has shown global-scale ionospheric outflow to be an immediate response to
solar-wind pressure pulses. Such imaging has also provided the first
measurements of solar wind and interstellar neutral atoms from inside the
magnetosphere. Radio sounding has revealed the internal structure of the
plasmasphere and identified plasma cavities as the source of kilometric
continuum radiation. These and numerous other scientific results now set the
stage for the extended mission of IMAGE in which the imaging perspective will
change markedly owing to orbital evolution while the magnetospheric environment
undergoes a transition from solar maximum toward solar minimum. 

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Space Science Reviews, 109 (1-4), 1-24, 2003