Nacreous clouds page #1

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Nacreous clouds or mother-of-pearl clouds are difficult to document properly. Very often there is a dazzling brightness close to horizon while only a few degrees higher the sky is quite dark with clouds showing pastell colours. Capturing the bright part and the colours into same exposure is always a compromise.
Nacreous cloud pastell colours are a bit like those in iridescence, but if sun is close to horizon or below it, then one is observing nacreous clouds. (Iridescence will be either gone or has turned into red and is indistinguishable from ordinary twillight clouds.) On my observing site I rarely see great nacreous clouds. Rather, they are peculiar twillight colours and long lasting red twillight well after cirrus clouds have turned black.
Typical view at sunset is in he00652: milky and "soft", whitish veil. This stuff becomes visible only at sunset (or rise); it can be seen only about an hour prior to sunset (or after sunrise). Later this turns into red "twillight looking" cloud like in he01053 with an extremely brigh part close to horizon. And a bit later all but bright horizon dims like in he01332.
More text on pages #2 and #3.


he00134

he00152

he00153

he00211

he00213

he00222

he00424

he00452

he00611

he00652

he00944

he01011

he01053

he01233

he01332

he01452

he01513

he01533

he01642

he01753

he01851

he02013

he02042

he02123

he02232

he02243

he02323

he02622

he02653

he02834

he02931

he03112

he03131

he03141

he03211

he03222



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