Directional movement of Noctilucent Clouds?

[Photosbykev]

Anyone care to enlighten me about the movement of NLCs wrt to lower 'normal' clouds? The NLCs seem to naturally move East to West with the normal  clouds going with the prevailing wind direction. Is it movement of the earth relative to the very high clouds creating this effect?

[LukeSkywatcher]

I can only guess that NLC's are so high up in the atmosphere that it is the rotation of the Earth that make them appear to move east to west (as the stars appear to do). Are NLC's even real clouds?. Clouds are water vapour/droplets held in suspension above us. NLC's are ice crystals reflecting sunlight. 

[Knight of Clear Skies]

I'm really not sure, I wonder if the apparent motion could have as much to do with the changing angle of the Sun as actual movement. This article claims they normally drift from NE to SW in the northern hemisphere. One thing to bear in mind is they are several hundred miles away so the direction of the prevailing wind at their location could be opposite to locally, as this map shows.

When I imaged them from Hertfordshire I used plate solving and trig to estimate the distance to the display and got a ballpark figure of several hundred miles, somewhere off the west coast of Norway, which came as quite a shock to me.

This site has a section on NLC movement (search for 'NLC Motion' on the page), it claims the movement is due to the Earth's rotation but I'm not quite sure what they mean by this. Hope that's some help, please let us know if you find out anything more.

[jambouk]

The rotation of the earth apparently:

http://www.nightskyhunter.com/Noctilucent%20Clouds.html

James

[LukeSkywatcher]

"When I imaged them from Hertfordshire I used plate solving and trig to estimate the distance to the display and got a ballpark figure of several hundred miles, somewhere off the west coast of Norway, which came as quite a shock to me".

Wow. That really is amazing. It just goes to show how high up they are if they are above the west coast of Norway but visible from your location.  

[Photosbykev]

The rotation of the earth apparently:

http://www.nightskyhunter.com/Noctilucent%20Clouds.html

James

This explanation seems to make sense