Latitudinal variation of the electron density over the northern polar cusp from
RPI/IMAGE observations

P. Nsumei, B.W. Reinisch, P. Song, X. Huang


When IMAGE flew through the northern polar region near 04 - 14 MLT, on March 4,
2003, the Radio Plasma Imager (RPI) on IMAGE satellite measured 10 electron
density profiles along the satellite track, each from the satellite to lower
altitudes along the magnetic field. The IMF was predominantly southward and the
kp index was 5- during the event. An enhancement in the density is observed near
dayside ~73 deg - 82 deg invariant latitude. The Tsyganenko 1996 (T96)
magnetospheric model shows that the topological separation between closed and
open field lines is near 70 deg. The enhancement may have occurred poleward of
the dayside cusp as a result of heating and ionization due to reconnection and
precipitation particles with some convection time delay.

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Presentation, Fall Meeting, American Geophysical Union, San Francisco, USA, 
8-12 December 2003