Ma. Kolpak et al., IMP-8 OBSERVATIONS OF A POLEWARD PLASMA CIRCULATION - EVIDENCE OF ENTRY INTO THE PLASMA MANTLE, Geophysical research letters, 25(17), 1998, pp. 3293-3296
Plasma data from IMP 8 are used to map the spatial structure of plasma
how in Earth's magnetosheath. Plasma and magnetic field data from ins
truments on ISEE-3 and WIND are used to normalize the IMP 8 magnetoshe
ath data to upstream solar wind conditions. For the majority of the da
ta, the magnitude and direction of plasma how inside the magnetosheath
agree well with gas-dynamic models. About 8% of the ISEE-3-normalized
velocity vectors and 3% of the WIND-normalized velocity vectors exhib
it a poleward circulation in the YZ plane. The observed circulation is
consistent with predictions for flow within the plasma mantle. The oc
currence frequency of these poleward hows increases further down the t
ail, consistent with predictions that the mantle width increases tailw
ard. Densities are lower where this how is observed, consistent with e
xpectations for the plasma mantle, but temperatures are higher and the
magnetic field magnitudes lower, the opposite of theoretical expectat
ions.