Today is Cloud Appreciation Day, and we can't get enough of these stunning, rare nacreous clouds. These iridescent formations are rarely seen and often appear in polar regions during cold conditions. Technically, they aren't clouds as we'd normally see, because they occur above the Troposphere, where all weather occurs. But, they form in the same way as clouds. They are also known as Polar Stratospheric Clouds and Mother-of-Pearl Clouds. They are most commonly seen in Arctic and Antarctic regions, such as these in Iceland. #nacreous #polar #clouds #shorts #internationalcloudday