unbelievable. Beautiful. Great.
These are words many people use to describe one of the most beautiful images of the sky: glowing clouds.
And the time is right for Canadians to try to see them for themselves, especially during this long weekend – if you have clear skies.
Every year, from about the beginning of June to August, these clouds – also called NLC or polar mesospheric clouds – appear in the northern sky.
They do not look like any of the better known clouds: they look almost overflowing, bright and shimmering when darkness descends, the sun slips out of sight and the stars begin to illuminate the sky, or when darkness begins to turn into daylight when the sun begins. to rise.
Another photo from the amazing show of light clouds this morning. Newcastle upon Tyne, United Kingdom. June 23, 2022 pic.twitter.com/FHWJlxnKs8
– @DavidBflower
The phenomenon seems to have a standard recipe for formation: an increase in water vapor, very low temperatures and particles – such as dust left by meteors in our atmosphere or even exhaust gases – on which water vapor can freeze.
NLC are also located incredibly high in the atmosphere, at about 80 kilometers above sea level. For comparison, the highest clouds that we associate with the weather are located at altitudes between five and 13 kilometers.
Silver clouds observed over Medicine Hat, Alta, on June 26. (Submitted by Jackie Armstrong)
It is also believed that there are few new phenomena. They were first reported in 1885, two years after the massive volcanic eruption of Krakatoa. Although the early belief was that this was due to the eruption and that they would disappear, they have been seen ever since.
How to see them
In the past, NLCs have been observed mainly in the high northern latitudes, making Northern Canada an ideal place to observe them. However, in recent years they have been seen further south, all the way to Utah and even Nebraska in the United States.
There is a belief that climate change also contributes to their development and even to their being seen in unprecedented latitudes. For example, in 2019, they were observed as far south as Joshua Tree, California. The leading theory is that with more greenhouse gases in the atmosphere, there is more water vapor on which they can form.
A 2019 study suggests that the emergence of NLC fluctuates from year to year and even from decade to decade, but in general they have become “significantly” more visible.
These shining clouds appear in the summer in the Northern Hemisphere as more water molecules travel upward from the lower atmosphere and mix with meteorite debris. In addition, this is the time when the mesosphere – where these clouds develop – is coldest.
WATCH | Scientists have captured a spectacular cloud of light over Canada:
Most of Canada is in a good position to see these rising clouds, although those in southern Ontario may have more difficulty because they are at a lower latitude.
If you are going to try to spot them, the key is to have a good view of the northern horizon. In this case, you really do not need to get to a place with a dark sky, as the clouds are bright, illuminated by the sun, which is below the horizon.
They most often appear about 30 minutes to two hours after sunset or 30 minutes to two hours before sunrise, as the sun should be approximately 5 to 13 degrees below the horizon.
And you will be able to distinguish them from the weather clouds, because these clouds will be dark, not bright NLC.
So if you are at a villa, in a park or just celebrating this weekend, be sure to look up. You never know what you will see.
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