Investigation of the Effects of IMF Orientation Upon Delivery of Plasma Sheet
Material to the Inner Magnetosphere

M.H. Denton, M.F. Thomsen, R.M. Skoug, M.G. Henderson, and C.J. Pollock


The orientation of the interplanetary magnetic field (IMF) is known to strongly
control the entry of solar wind material into the Earth's magnetosphere. Within
the magnetosphere various plasma properties and parameters are known to be IMF
dependent. In this study we use Magnetospheric Plasma Analyser (MPA) data from
the LANL constellation of satellites located in geosynchronous orbit, in
conjunction with the imaging capabilities of the Medium Energy Neutral Atom
(MENA) imager on-board the IMAGE satellite, to determine the effects of IMF
orientation on the transport of plasma from the plasma sheet into the inner
magnetosphere. A statistical study of MPA data is performed to determine bulk
plasma properties at geosynchronous orbit in relation to IMF-By and IMF-Bz. In a
parallel statistical study we use MENA data to determine the location of the
peak nightside energetic neutral atom (ENA) emissons and to investigate whether
this peak, which may indicate substorm injection regions, is IMF-dependent.

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Presentation, Fall A.G.U. Meeting, San Francisco, CA, 13-17 December 2004