Telescopic High Speed Observations of SpritesGeoff McHarg1, Ryan Haaland2 Takeshi Kanmae3, and Hans Stenbaek-Nielsen31 United States Air Force Academy2 Fort Lewis College3 University of Alaska, Fairbanks

Observational setupLangmuir LabSocorro New Mexico14-15 July 2010500 mm Phantom 7.3 1.26x0.63o FOV 43mrad/pixel 16000fps85mm Phantom 7.0 7.3x3.7o FOV 249mrad/pixel 10000fps25 mm Watec 14.2x10.4o FOVAz-El mountHandtriggeredTwo remote triangulation sitesWatec only

Example 15 July 201007:06:09 UT C spriteRange=311kmSpatial mappingC1 (85mm): 77 m/pixC2(500mm): 13 m/pixHalo Evident in C1Not as clear in C2Splitting evident in bothC1 1ms avg. with C2 FONote: Splitting of left streamer below c2 FOV, while right streamer splits in C2 FOVWatec with C1 and C2 FOV

07:06:09 splittingKammae notes similarity of large streamer with lab streamers (AGU-2010)McHarg et al. [2010] reported on splitting streamers using 300 mm lensWider streamers split (390m), narrow streamers propagate (193m)Streamers brighten before they splitNew observations reveal Streamers splitting into multiple smaller pieces (8 in this case)Streamers as narrow as ~40mPdmin dependent on altitude but ~1 bar-mm if @ 75 km

Example 14 July 201004:58:55 JellyfishRange=421 kmSpatial mappingC1 106 m/pixC2 18 m/pixHalo very obvious in C1, again less so in C2Very short, ~5.5msC1 1ms avg. with C2 FOVNote: Telescope looking in central region of jellyfish

04:58:55 splittingSplitting at same time as development of afterglowVery fine afterglow structures formClouds in FOV very evident in C1Make conclusions about intensity variations in C2 suspect Could the rapid decay visible across the FOV be due to increased conductivity from streamers?

ConclusionsHigh speed telescopic imaging yields new views of streamer dynamicsStreamer splitting shows different numbers of daughter streamersWhy?Are streamers self-similaror is this due to the amorphous nature of streamers and simply due to smearing?Streamer width of ~40m observedHigher speeds and more resolution still warrantedAGU Dec 2007. AE42A-07

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