We report on a novel scenario of subauroral arcs within strong subauroral ion drifts (SAID)‐STEVE and Picket Fence. Their explanation requires a local source of low‐energy,
Strong thermal emission velocity enhancement (STEVE) is an optical phenomenon of the subauroral ionosphere arising from extreme ion drift speeds. STEVE consists of two distinct components in true‐color imagery: a mauve or whitish arc extended in the magnetic east–west direction and a region of green emission adjacent to the arc, often structured into quasiperiodic columns aligned with the geomagnetic field (the “picket fence”). This work employs high‐resolution imagery by citizen scientists in a critical examination of fine‐scale features within the green emission region. Of particular interest are narrow “streaks” of emission forming underneath field‐aligned picket fence elements in the 100‐ to 110‐km altitude range. The streaks propagate in curved trajectories with dominant direction toward STEVE from the poleward side. The elongation is along the direction of motion, suggesting a drifting point‐like excitation source, with the apparent elongation due to a combination of motion blur and radiative lifetime effects. The cross‐sectional dimension is <1 km, and the cases observed have a duration of
- Award ID(s):
- 1821135
- NSF-PAR ID:
- 10375263
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- AGU Advances
- Volume:
- 1
- Issue:
- 4
- ISSN:
- 2576-604X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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