70:, at subauroral latitudes, typically in the local time sector between 18:00 hours and 22:00 hours. They can occur individually, or as multiple events. SAIDs are characterised by a reduced density of ions, a strong westward flow, and an increased temperature. They can last between 30 minutes and 3 hours. The exact characteristics of SAID events appear to have
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MacDonald, Elizabeth A.; Donovan, Eric; Nishimura, Yukitoshi; Case, Nathan A.; Gillies, D. Megan; Gallardo-Lacourt, Bea; Archer, William E.; Spanswick, Emma L.; Bourassa, Notanee; Connors, Martin; Heavner, Matthew; Jackel, Brian; Kosar, Burcu; Knudsen, David J.; Ratzlaff, Chris; Schofield, Ian (14
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Although studied for decades, prior to the formal discovery of STEVE, SAIDs had never been associated with an optical emission. STEVE was associated with a particularly extreme SAID, with a velocity over twice the norm and 100
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Galperin, Y. I.; Ponomarov, Y. N.; Zosinova, A. G. (1973). "Direct measurements of ion drift velocity in the upper ionosphere during a magnetic storm".
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discovery paper suggested the first link between this optical emission’s occurrence and that of an extremely fast and hot SAID event.
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Spiro, R. W.; Heelis, R. A.; Hanson, W. B. (August 1979). "Rapid subauroral ion drifts observed by
Atmosphere Explorer C".
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Anderson, P. C.; Heelis, R. A.; Hanson, W. B. (1991). "The ionospheric signatures of rapid subauroral ion drifts".
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232:"Mystery of Purple Lights in Sky Solved With Citizen Scientists' Help"
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hotter. STEVE has presented a new way for scientists, including
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291:He, Fei; Zhang, Xiao-Xin; Chen, Bo (June 2014).
297:Journal of Geophysical Research: Space Physics
55:. Though not traditionally associated with an
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363:"Meet 'Steve,' a Totally New Kind of Aurora"
27:), also known as a polarisation jet, is an
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39:. First discovered in 1971, a SAID is a
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66:SAIDs are observed equatorward of the
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361:Skibba, Ramin (15 March 2018).
258:Journal of Geophysical Research
230:Patel, Kasha (14 March 2018).
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112:Geophysical Research Letters
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132:10.1029/GL006i008p00657
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16:Atmospheric phenomenon
369:. National Geographic
31:phenomenon driven by
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21:subauroral ion drift
367:National Geographic
309:2014JGRA..119.5076H
270:1991JGR....96.5785A
191:2018SciA....4...30M
159:1973KosIs..11..273G
147:Cosmicheskie Issled
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68:auroral zone
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72:solar cycle
29:atmospheric
395:Ionosphere
389:Categories
94:References
53:ionosphere
33:substorms
217:29546244
76:seasonal
305:Bibcode
266:Bibcode
208:5851661
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153:: 273.
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373:17 May
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61:STEVE
375:2019
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243:2019
236:NASA
213:PMID
49:ions
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