Journal of Geophysical Research Space Physics
Supporting Information for
Polar Cap Precursor of Nightside Auroral Oval Intensifications Using Polar Cap
Arcs
Ying Zou
1
; Yukitoshi Nishimura
1
; Larry R. Lyons
1
; Eric F. Donovan
2
; Kazuo Shiokawa
3
,
J. Michael Ruohoniemi 4 ; Kathryn A. McWilliams 5 ; Nozomu Nishitani 3
1. Department of Atmospheric and Oceanic Sciences, University of California, Los
Angeles, USA
2. Department of Physics and Astronomy, University of Calgary,
Calgary, Alberta, Canada
3. Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya, Japan
4. The Bradley Department of Electrical and Computer Engineering, Virginia
Tech, Blacksburg, Virginia, USA
5. Institute of Space and Atmospheric Studies, University of Saskatchewan, Saskatoon,
Saskatchewan, Canada.
Contents of this file
Figures S1
Additional Supporting Information (Files uploaded separately)
Captions for Movies S1 to S3
Introduction
This supporting information provides captions of 630.0 nm movies of the three case studies, which are in the same format as the selectively snapshots in the main article. It also includes a figure showing the comparison of 630.0 nm and 557.7 nm intensity for these three cases and a theta aurora event, providing information on the precipitation source of corresponding arcs.
1

Movie S1. 630.0 nm movie showing the association of a polar cap arc to PBI activity within a thick auroral oval on Feb 6, 2013, in the same format as Figure 1 in the main article. A running median intensity over 2 h has been subtracted.
Movie S2. 630.0 nm movie showing the association of two polar cap arcs to nonpoleward expanding intensifications within a thin auroral oval on Mar 20, 2009, in the same format as Figure 3 in the main article. A running median intensity over 2 h has been subtracted.
Movie S3. 630.0 nm snapshots showing the association of a polar cap arc to poleward expanding intensifications within a thin auroral oval on Mar 17, 2010, in the same format as Figure 5 in the main article. A running median intensity over 2 h has been subtracted.
2

Figure S1 .
RESU snapshots of the 630.0 nm emissions mapped to altitude 250 km (first row), 557.7 nm emissions mapped to 110 km (second row), their ratio (third row), and keograms of absolute 630.0 nm intensity and its ratio to 557.7 nm intensity (bottom row).
Three case studies are presented in the first three columns and an example of a theta aurora is shown in the last column. Note that the polar cap arcs in the current study are much fainter in 630.0 nm intensity and have a much higher 630.0 nm/557.7 nm intensity ratio compared with the theta aurora. The precision of intensity ratios is subject to mapping uncertainty.
3

1