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.
What causes polar stratospheric clouds?
Polar stratospheric clouds (PSCs) are formed in the polar ozone layer when winter minimum temperatures fall below the formation temperature of about −78°C. Reactions on liquid and solid PSC particles cause the highly reactive chlorine gas ClO to be formed, which catalytically destroys ozone (see Q9).
Why are there no clouds in Antarctica?
Although the Antarctic atmosphere is normally freezing many Antarctic clouds contain both water droplets and ice crystals. In the interior of Antarctica the temperature is very low (below -50°C) and here the clouds tend to be made up solely of ice particles.
Where are nacreous clouds found?
stratosphere
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.
How do you get nacreous clouds?
They are most likely to be viewed when the Sun is between 1º and 6º below the horizon and in places with higher latitudes, such as Scandinavia and northern Canada. For this reason, they are sometimes known as polar stratospheric clouds.
How are polar mesospheric clouds formed?
Polar mesospheric clouds (PMCs)—also called noctilucent clouds—are very thin ice clouds that form around 83 km near the polar summer mesopause. The polar summer mesopause is the coldest region of the atmosphere because of cooling that results from the gravity wave-driven circulation in the mesosphere.
How polar stratospheric clouds cause ozone depletion?
Polar stratospheric clouds (PSCs) play a central role in the formation of the ozone hole in the Antarctic and Arctic. These reactions lead to the production of free radicals of chlorine in the stratosphere which directly destroy ozone molecules. …
How do you identify 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). They are best observed during civil twilight, when the Sun is between 1 and 6 degrees below the horizon, as well as in winter and in more northerly latitudes.
What type of clouds are formed in the mesosphere?
Polar mesospheric clouds—also known as noctilucent or “night shining” clouds—form between 76 to 85 kilometers (47 to 53 miles) above the Earth’s surface, near the boundary of the mesosphere and thermosphere, a region known as the mesopause. At these altitudes, water vapor can freeze into clouds of ice crystals.
How are cirrus clouds made?
Cirrus clouds form from the ascent of dry air, making the small quantity of water vapour in the air undergo deposition into ice (to change from a gas directly into a solid). Cirrus is made up completely of ice crystals, which provides their white colour and form in a wide range of shapes and sizes.
How are clouds formed and how are they formed?
The Short Answer: Clouds are created when water vapor, an invisible gas, turns into liquid water droplets. These water droplets form on tiny particles, like dust, that are floating in the air.
How are nacreous clouds different from other clouds?
Nacreous clouds are rare and very high clouds, known mainly for the coloured light they reflect after sunset and before sunrise. The colours are reminiscent of the colours which reflect from a thin layer of oil on top of water, an effect known as iridescence.
How are clouds formed in the southern Indian Ocean?
Clouds are created when water vapor, an invisible gas, turns into liquid water droplets. These water droplets form on tiny particles, like dust, that are floating in the air. A camera on NASA’s Terra satellite captured this image of clouds over the Southern Indian Ocean. Image credit: NASA/JPL-Caltech. You hang up a wet towel and,
Where do nacreous clouds form in the 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.