Took these images last night 8-9 July 2013 The noctilucent clouds (NLC) were very bright, see the panoramic view. As can be seen from this second video-clip the NLC were revolving like a slow motion tornado. The rotation appears to have just been starting in the first wide angle video but is shown better in the close up. This zoomed in second video was 30 frames (taken at 8 second exposure with a 9 second gap). Is rotation in the NLC a usual occurrence? I haven't noticed it before but I usually just tack stills. this is the first time I have tried animating my stills. I've had trouble uploading these videos but they can be seen on my flickr page @ www.flickr.com/photos/astrospade_1/9002092122/
Hi, These sharp boundaries are thought to be zones where "gravity waves" are influencing the NLC. I'm not sure what you mean by rotation? There is the usual streaming as the clouds are carried the meospheric winds but I don't see anything tornado like. Can you zoom us in to where on the frame you mean. However what I think you've caught is an occurence of what I call type L. Around the sharp boundaries there are well defined elliptical features (probably more circular with a better viewing angle). As distinct entities these seem to be quite rare. My own video was too crude and low res to see these. Good work in any case! cheers, Bill.
Its more of a rotating cell of cloud with the lower clouds rising up the sides of the cell as as they rotate. Ive included a 30fps animation at the address below this shows it a little better. www.flickr.com/photos/astrospade_1/9028113874/
wow yea I see rotation; or at least it gives the impression of matter falling from the right into a clockwise vortex if viewed from above, evaporating up high.. would be great to see it from above to find out .. either way, great timelapse Alan .. similar to this one by Pete Lawrence: spaceweather.com/gallery/indiv_upload.php?upload_id=82871