Noctilucent clouds 19./20.7.2012

Observed phenomena: Noctilucent clouds
Observed NLC forms:

  • I (Veil)
  • IIa (Bands with diffuse, blurred edges)
  • IIb (Bands with sharply defined edges)
  • IIIa (Short, straight and narrow streaks)
  • IIIb (Wave-like structure with undulations)
  • O (Unusual forms)

Brightness of the NLCs: 3 (clearly visible, standing out sharply against the twilight sky)
Colour of the NLCs: pale-blue

Upper limit: 150°
Lower limit: 3°

Apparent direction of movement: south

Date: 19./20.7.2012
Time: 00:55-02:10
Observing place: Kuru, Ylöjärvi, Finland
Observing method: Photography
Technical information about photographing equipment: Canon EOS 1100D, Canon EF-S 18-55mm IS, Samyang 8mm fish eye

This NLC display was clearly a display of band-wave -type. This display was dominated by long approximately N-S oriented longnitudinal bands (both with blurred and sharp -edges) and transverse waves (mostly type IIIb, but also IIIa). The start of the display was a modest one, but it developed into a nice display with NLC’s covering over half of the area of the sky extending over zenith! The brightness of the NLC’s was mediocre and colour was pale-blue. The apparent movement of the NLC’s seemed to be southwards.

In the end of my observing session, there was an interesting detail visible in the NLC’s. There was a long, bifurcated NLC band, which was casting a long, dark shadow into the NLC veil behind it (@02:06).


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