Travelers heading to Scandinavia in the coming days can witness some of the world's most stunning clouds, known as polar stratospheric clouds (PSCs), due to the region's extreme cold.
According to meteorological reports, these vibrant clouds have been observed in Sweden, Norway, and Finland, where temperatures have plummeted to -30 °C. Residents of Lapland are also experiencing these phenomena, with daily maximum temperatures not exceeding -20 °C. Such extreme low temperatures are essential for the formation of PSCs.
For those wishing to catch a glimpse of this celestial spectacle, early risers will be rewarded, as the most beautiful polar stratospheric clouds appear just before sunrise during twilight, when the sun is positioned approximately 1° to 6° below the horizon.
Ice polar stratospheric clouds are formed when temperatures drop to extremely low levels and are also referred to as nacreous clouds. Another type of PSC contains nitric acid and water and is often linked to ozone layer depletion.
According to the Meteorological Dictionary, this cloud type predominantly occurs during winter months in the lower polar stratosphere at altitudes ranging from 15 to 30 kilometers. They were first identified through satellite measurements in 1979.