PBI by definition Optical data THEMIS data Rocket data PBI Classification PBI by definition Optical data THEMIS data Rocket data

Poleward Boundary Intensification latitude Time (2 hours) Differences between a substorm and PBI Substorm has an onset at a latitude equatorward of poleward boundary PBIs are repeated events Substorm onset arc has a much shorter residency time -camera data showed PBI to be very dynamic and structured and sustained over Kak -theory colleagues said PBI involved alfvenic acceleration Plot from Henderson, 1998

Bursty Bulk Flows These figures from Nakamura et al. (2001) show the spatial relationship between the BBF footpoint and the associated ionospheric auroral signature. During our event, the THEMIS footpoint is within one hour east of the rocket trajectory, which matches this picture. -earthward plasma flow in the tail -upward current along the duskward edge, which is where you will see the electron precipitation -want THEMIS slightly to the east of the auroral activity This case study can be used to look at the correlation among flows in the magnetotail, auroral intensifications detected on ground-based instruments, and Alfvén waves on the rocket.

Optics from time of flight UT time of flight 11:04 0s 11:08 240s 11:11 420s 11:14 600s 11:15 660s 11:16 720s From Zesta, 2002: Equatorward extending -represent modes of energy and momentum transfer from the separatrix toward the earth and through the plasma sheet Non-equatorward extending -represent dynamic structures, such as result from instabilities, along the separatrix without propogation in the plasma sheet -first look at electron data from e-e arc, then at data from tall rays

Electrons from PBI at 465s (equatorward-extending)

Electrons from PBI at 465s (non-equatorward-extending) Tall rays Alfven wave induced electron precipitation