Where are nacreous clouds found?
lower stratosphere
Nacreous clouds form in the lower stratosphere over polar regions when the Sun is just below the horizon. The ice particles that form nacreous clouds are much smaller than those that form more common clouds.
How rare are polar stratospheric clouds?
Polar stratospheric clouds (PSCs) are clouds in the winter polar stratosphere at altitudes of 15,000–25,000 m (49,000–82,000 ft)….
| Polar stratospheric cloud | |
|---|---|
| Precipitation cloud? | No |
Why are polar stratospheric clouds dangerous?
During the return of spring sunlight these radicals destroy many ozone molecules in a series of chain reactions. Cloud formation is doubly harmful because it also removes from the stratosphere gaseous nitric acid that would otherwise combine with ClO to form less reactive forms of chlorine.
What types of clouds are in Antarctica?
The areas around the coast of Antarctica are amongst the cloudiest places in the world.
- Lenticular clouds. When mountains provide an obstruction to the flow of winds there is strong turbulence and uplift and lenticular clouds frequently form.
- Nacreous clouds.
- Noctilucent clouds.
Where can you see stratospheric clouds?
Ice polar stratospheric clouds, or nacreous clouds, occur mainly at high latitudes during the winter when temperatures in the stratosphere fall below the frost point. They are most common in Antarctica, but have also been observed in the Arctic, Scotland, Scandinavia, Alaska, Canada and the northern Russian Federation.
What causes nacreous clouds?
Nacreous clouds will also only form when the temperature in the stratosphere is below a chilly -78°C, which turns any moisture in the air into super-cooled liquid or ice crystals. This light is refracted by the ice crystals in the clouds, a process known as cloud iridescence, producing the shimmering rainbow effect.
Are polar stratospheric clouds bad?
Casting an iridescent pastel hue across the sky, rare polar stratospheric clouds – also known as nacreous clouds because of their ‘mother of pearl’ color – are one of the most beautiful of all cloud formations. But they are also the most destructive for the ozone layer.
What do stratospheric clouds do?
These high altitude clouds form only at very low temperatures help destroy ozone in two ways: They provide a surface which converts benign forms of chlorine into reactive, ozone-destroying forms, and they remove nitrogen compounds that moderate the destructive impact of chlorine. …
What are nacreous clouds made of?
ice crystals
While clouds usually don’t form in the stratosphere because it is normally too dry for ice crystals to develop, nacreous clouds can be created there because they consist of ice crystals, supercooled water and nitric acid.
How do polar stratospheric clouds occur?
PSCs are clouds that form when water vapor enters the stratosphere and when temperatures are cold enough for water vapor to condense there. During the winter, the high latitudes receive very little to no solar radiation, so temperatures drop significantly during this period, known as polar night.