Image of IMAGE in space

Seasonal and Solar-Cycle Changes in the Magnetosphere-Ionosphere Connection

Seasonal Changes

The magnetosphere is connected to the ionosphere through currents of particles which are known to affect the heating and other properties of the upper atmosphere. Observations from the IMAGE satellite's RPI instrument, combined with data from the Polar satelite's PWI instrument have uncovered seasonal changes in the Auroral Kilometric Radiation emitted by electrons accelerated in the polar auroral regions. The AKR emissions are more intense during the winter than during summer, and the auroral density cavity is at lower altitudes during the winter than the summer. The IMAGE-Polar long term study since 2000 also disproved a 'popular' belief among space physicists that AKR emissions are more intense during solar maximum than solar minimum. The studies found evidence for just the opposite behavior.

(2003: Green et al.)

Related IMAGE Discoveries

Additional Information

Magnetosphere -The region of space surrounding Earth where its magnetic field controls the movement of charged particles. It varies from about 60,000 kilometers on the sunward side 'bouw shock' to over 1 million ki8lometers in the anti-solar magnetotail region.

Auroral Kilometric Radiation - Very low frequency radio radiation produced in 'bite-out' regions of the plasmasphere within the equatorial plane.

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Dr. S. Odenwald,, +1-301-286-6953
NSSDC, Mail Code 630, NASA Goddard Space Flight Center, Greenbelt, MD 20771
NASA Approval: J. L. Green,
Rev. 1.0.0, 24 July 2004, EVB II