Paper#: 78
Poster #: 25
Session Name: Poster Session 2
Room: East Ballroom
Day: Thursday
Time: 10:10 a.m.-Noon
Abstract Title: BBF Intrusion to the Inner Plasma Sheet as Inferred from Auroral Observations
PresentSurname: Kauristie, K.
All Authors: K. Kauristie, O.Amm, V.A. Sergeev and M.V. Kubyshkina, J. Jussila, E. Donovan, K. Liou
Abstract : The physics of the bursty bulk flows (BBFs) interaction with the near-Earth plasma is interesting from the viewpoint of substorm research, because the magnetosphere-ionosphere coupling processes of BBFs resemble in many respect substorm processes, although the azimuthal scale sizes are different. We address this issue from the basis of auroral streamer observations which were made during a well-documented BBF-period. In our case an equatorward intruding auroral streamer reached the region of the proton oval of 486 nm (H-beta) luminosity which according to an appropriate magnetic field model mapped to geocentric distances of Xgse ~ -6...-8 Re in the magnetotail. A significant enhancement (30 %) in the H-beta luminosity implying an abrupt pressure enhancement in the inner magnetosphere was recorded at the moment when the equatorward end of the streamer reached the proton oval. However, both auroral and equivalent current observations suggest that the plasma jet did not stop or dissolve, but rather diverted in the azimuthal direction. According to ground magnetic field data the jet generated R1-type FAC system while propagating Earthward, but we could not find any clear signatures of a R2-type current system which under certain conditions should accompany the abrupt pressure buildup and field-line diversion in the near-Earth region.