NLC time again

I have to say I dont see it, thats not to say its not there, maybe other do so.?

We all see things differently. Because i see them as green(ish) i thought they were something to do with the aurora's........................

PJ,
what happens is that cold air comes down from the artic and forms ice on dust left by meteors at at altitude of 85km, much higher then normal clouds (5-15km).They're seen this time of year because the sun is not far from the northern horison and is therefore near enough to illuminate/reflect of it.

Some say that they are visible only around solar minimum as an active sun disturbs the upper atmosphere preventing these clouds from forming.

Last night we saw the NLCs for a few degrees above the horison in the NW/N and work its way to right on the horison, 2 hours later a NLC formed in the NE right on the horison and increased in altitude as the Sun got nearer to the horison, so it looks like some sort of reflection/sunangle going on here. This could seriously help in predicting NLCs, it would then be a matter of figuring how dirty the atmosphere up there is. I wish I had taking timings of the NLCs and it altitude.

PJ,
what happens is that cold air comes down from the artic and forms ice on dust left by meteors at at altitude of 85km, much higher then normal clouds (5-15km).They're seen this time of year because the sun is not far from the northern horison and is therefore near enough to illuminate/reflect of it.

Yeah thats about as much as i knew (maybe a bit more) about them.

So i'm right in saying you need a pretty clear view towards the horizon to see them? i mean they dont form 45 degrees up or anything even close to that.?

So i'm right in saying you need a pretty clear view towards the horizon to see them? i mean they dont form 45 degrees up or anything even close to that.?

don't think I've seen them much above 10-15 degrees.

Dave is right.
It's absolutely reflection.
When the sun is lower it illuminates at an acute angle
and the clouds 'appear'. These are on the horizon and the
striations look tightly packed due to perspective.
As the sun increases in altitude more of the light reflects off of the NLC
and therefore is appears to spread up higher and 'loosen out'.

When the cloud is there, it's just the particular angle of the sun that makes
it 'appear'

Obviously this diagram is a SEVERELY SIMPLIFIED indication
as to what I believe is happening.

Ah, now I know why you studied Art.