Substorm plasma sheet ion pressure profiles

[1] The plasma sheet pressure, temperature, and density profiles inferred from DMSP observations are used to investigate substorm growth, expansion, early-recovery, and late-recovery phases. During the growth phase, the pressure peaks at the inner edge of the plasma sheet. The premidnight pressure peak is associated with the temperature peak, while the postmidnight peak is associated with the density enhancement. After the substorm onset, the pressure at the inner edge diminishes. Instead, the pressure peaks at premidnight from X =-10 to - 40 R-E, which can be associated with temperature enhancement. During the early and late recovery phases, the pressure peaks at postmidnight, which is associated with a cold, dense ion population, possibly resulting from ion outflow and the substorm current systems. In the near-Earth region, the entropy decreases after substorm onset, but the specific entropy appears to be roughly conserved.