Substorm onset observations by IMAGE-FUV: Southern Hemisphere 2003-2005

Frey, H.U., Mende, S.B.


Over the first 2.5 years of operation (May 2000 to December 2002), the FUV
instrument on the IMAGE spacecraft observed more than 2400 substorm onsets in
the Northern Hemisphere. The list of all observed onset is published in [Frey et
al., 2004]. In 2003, the fast migration of the line of apsides (50° per year)
moved the IMAGE orbit apogee across the equator into the southern hemisphere.
1300 substorm onsets could be detected between the ~2.5 years of January 2003 to 
April 2005. Most of them were made in the Southern Hemisphere. Here we compare 
the major properties of the southern substorm onsets (absolute value of the 
onset geomagnetic latitude and MLT) with the results from the northern
hemisphere. We find similar values, regardless of the different phases within
the solar cycle for both data sets.

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Fall Meeting, American Geophysical Union, San Francisco, U.S.A., 
5-9 December 2005