•	Field-aligned plasma structures found to provide key signatures of magnetospheric boundaries.
	•	Persistent large-scale Te enhancements causally linked to downward magnetosheath heat flux in the cusp.
	•	Filamentary Te enhancements produced by Alfvenic electron precipitation at the nightside polar cap boundary.
	•	Characteristic energy gradients and auroral ionospheric cavities mark the edge of the nightside polar cap.
	Doe, R. A., J. D. Kelly, E. R. Sanchez “Observations of persistent dayside F region electron temperature enhancements associated with soft magnetosheathlike precipitation,” J Geophys Res., Vol. 106, 3615, 2001.
	Doe, R. A., J. F. Vickrey,E.J. Weber, H. A. Gallagher and S. B. Mende “Ground-based signatures for the nightside polar cap boundary,” J Geophys Res., Vol. 102, 19989, 1997.
	Kagan, L. M., M. C. Kelley, and R. A. Doe “Ionospheric electron heating by structured electric fields: Theory and experiment,” J Geophys Res., Vol. 101, 10893, 1996.