Sun-Aligned Polar Cap Auroral Arcs.

• Main Author: Kan,J R
• Other Authors: ALASKA UNIV FAIRBANKS GEOPHYSICAL INST
• Format: Text
• Language: English
• Published: 1984
• Subjects: Atmospheric Physics; Snow; Ice and Permafrost; *AURORAE; *POLAR CAP; MAGNETIC FIELDS; OBSERVATION; CONVECTION; ALIGNMENT; SUN; PLASMA SHEATHS; Auroral arcs; WUAFGL2311G2EB; PE61102F; Ice; permafrost
• Online Access: http://www.dtic.mil/docs/citations/ADA148052; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA148052

A model of polar cap auroral arcs is proposed under the assumption that the magnetic field reconnection occurs in the cusp region on tail field lines during northward interplanetary magnetic field (IMF) conditions. Requirements of a convection model during northward IMF are enumerated based on observations and fundamental theoretical considerations. The theta aurora can be expected to occur on the closed field lines convecting sunward in the central polar cap while the less intense polar cap arcs can occur either on closed or open field lines. The dynamo region for the polar cap arcs is required to be on closed field lines convecting tailward in the plasma sheet which is magnetically connected to the sunward convection in the central polar cap. (Author)