Progress in Understanding Magnetic Reconnection at the Earth's Magnetopause

Stephen A. Fuselier


Over the past ~2 years, there has been significant progress in understanding the
stability and location of magnetic reconnection at the magnetopause.  Both of
these aspects of reconnection required development and verification of several
new observational techniques.  This talk focuses on two techniques and their
results.  Both techniques are applied to data from the Earth's magnetospheric
cusps.  The first technique uses observations of precipitating protons in the
ionosphere from the IMAGE spacecraft.  Using this technique, reconnection is
shown to be steady for many hours.  This result is particularly important for
northward IMF, where the reconnection site can be located at high latitudes. 
The second technique uses in situ observations of the low energy cutoffs of
precipitating ions to determine the distance from the spacecraft to the
reconnection site.  This technique is used to show that both anti-parallel and
component reconnection occur at the magnetopause.  These new results are
encouraging for future missions, like the Magnetospheric Multiscale mission,
which will investigate reconnection sites in situ.  They also raise important
questions about the overall magnetic topology at the magnetopause.

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Space and Cosmic Ray Physics Seminar, University of Maryland, March 14, 2005