On the 31st of Januar I saw these clouds which I estimated to be very high in the atmosphere. I belived they could be mother of pearl clouds so I studied them for half an hour until sunrise. They never showed any strong iridescence so they are not mother of pearl clouds.
But when I got aware of that they had seen mother of pearl clouds in Norway on the same day 200 km from were the photo is shot I believe they are PSC.
/Mats