Cumulus Support

Hi,
With the arrival of the summer months comes the NLC season in the northern hemisphere.
There have been several decent displays already but the one last night was particularly interesting.
My timelapse video is here:

https://www.youtube.com/watch?v=oR9Rvk1 ... FDplXGcF6w

The NLC is moving rapidly in a strong generally ese wind. A rough (and I stress rough) estimate of the speed is 225mph/360kph!
It's a fast air flow up there!

cheers,
Bill.

Nice, not much of a night up there at the moment, not that we have much here either!

Nice work Bill
Is there there some sort of interference pattern developing for a while there between 2 layers?

G'day Gordon,

Great to hear from you! Although not absolutely uniform NLC tends to form in only one layer. These patterns seem to be caused by turbulence.
What generates that turbulence is a matter of debate. Whilst blowing extremely fast, as in this case, there can be quite a steep gradient in air velocity through the mesopause. It is quite a definite boundry (thats why the NLC form there) so that might have something to do with it.

Cheers,
Bill.