Photometry of dayside auroras during solar minimum 1 This article is part of a Special issue that honours the work of Dr. Donald M. Hunten FRSC who passed away in December 2010 after a very illustrious career.

• Published in: Canadian Journal of Physics
• Main Authors: McEwen, D.J., Sivjee, G.G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2012
• Subjects: General Physics and Astronomy; Antarctic; Antarc*
• Online Access: http://dx.doi.org/10.1139/p11-137; http://www.nrcresearchpress.com/doi/pdf/10.1139/p11-137

An examination is made of Antarctic dayside auroras to establish how they relate to solar wind strength under the quiet conditions of the recent extended solar minimum when the solar wind pressure was weak and the interplanetary magnetic field B z is small. It is found that, during the many days of observation, the aurora is detected even with the most stable and quiet conditions. On such occasions the 630 nm OI emission can be as low as 50 R, but is unambiguously and continuously detectable through each noon. This is above an airglow intensity of about 30 R. For these quiet conditions there is no evident relation between the solar wind dynamic pressure or interplanetary magnetic field B z and dayside auroral intensity. This suggests that there is no effective reconnection under these minimal conditions and the particle source for the dayside aurora could be within the magnetosphere.