Paper#: 66
Poster #:
Session Name: Workshop 2C: Particle/MHD Substorms
Room: 200ABC
Day: Monday
Time: 4:30-4:50 p.m.
Abstract Title: Checking Interchange Stability of the Midtail Plasma Sheet
PresentSurname: Golovchanskaya, I. V.
All Authors: I.V. Golovchanskaya, Y.P. Maltsev
Abstract : Gold’s criterion of interchange stability has been checked in the plasma sheet at tailward distance X= -16 to ^60 Re. The value of pV^(5/3) was calculated along the noon-midnight meridian directly from the Fairfield database and with the use of T96 magnetic field model. This value turned out to grow downtail everywhere except the region X= -30 ^50 Re where under very quiet geomagnetic conditions its gradient is directed earthward. Hence interchange structures relevant to fast magnetospheric flows and sun-aligned arcs can develop here. Other regions that may be interchange unstable are those of field-aligned currents. Though the radial gradients can be stable here with respect to Gold's criterion, in these regions according to the Vasyliunas formula should be a directional difference between the vectors grad p and grad V caused by the electric field or any other external force. The resulting interchange structures can be related to discrete auroral arcs which are known to be embedded in region 1 field-aligned currents.