These mystifying clouds are called Polar Mesospheric Clouds, or PMCs, when they are viewed from space and referred to as "night-shining" clouds or Noctilucent Clouds, when viewed by observers on Earth. The clouds form in an upper layer of the Earth’s atmosphere called the mesosphere during the summer and can be seen from the high latitudes on Earth.
Image Courtesy of NASA/Veres Viktor
Noctilucent Clouds
Noctilucent clouds (NLC’s) or polar mesospheric clouds (PMC’s) are found very high in the Earth's atmosphere. They are called Polar Mesospheric Clouds when they are viewed from space, and are referred to as noctilucent clouds when viewed by observers on
Earth. Unlike lower
clouds that are associated with
weather, these clouds form at the very edge of space in the atmospheric layer called
the mesosphere. Like some of the clouds we see more regularly, scientists think these clouds are made of frozen water or ice crystals.
As you can see from the image, NLC’s are seen best just after sunset. They glow an electric, blue-white. They are normally seen from locations near the poles of the Earth, but in recent years, they have been seen at much lower-latitude locations (like Colorado or Virginia in the U.S.). It’s this change in the locations of NLC’s that makes scientist think they may be a sign of global climate change on Earth, specifically global warming which is influenced by human activity. Scientists will look into this possibility with a new atmospheric mission, AIM (The Aeronomy of Ice in the Mesosphere).
These eerie looking clouds have only been studied in the recent past. Now, people are becoming more aware of NLC's. You too can be an observer of these clouds and can even share that information with others on the Internet!
You might also be interested in:
Earth’s climate is warming. During the 20th Century Earth’s average temperature rose 0.6° Celsius (1.1°F). Scientists are finding that the change in temperature has been causing other aspects of our planet
...more
There are many different ways that the plants, animals and other life on our planet, affect climate. Some produce greenhouses gases that trap heat and aid global warming through the greenhouse effect,
...more
Do you know what the highest clouds in the atmosphere are called? Polar Mesospheric Clouds (PMC’s), or noctilucent clouds (NLC’s)! The Aeronomy of Ice in the Mesosphere (AIM) mission will be launched in
...more
Observations of noctilucent or "night-shining" clouds were first reported in the summer of 1885. The observations were made in northern Europe and Russia. In the late 1880’s, it was proposed that the clouds
...more
Phenomena in the Polar Atmosphere There are some unique phenomena that happen in the atmosphere that is above the Earth's polar regions. Read on to discover more about some of the unique parts of the polar
...more
Rainbows appear in the sky when there is bright sunlight and rain. Sunlight is known as visible or white light and is actually a mixture of colors. Rainbows result from the refraction and reflection of
...more
The Earth travels around the sun one full time per year. During this year, the seasons change depending on the amount of sunlight reaching the surface and the Earth's tilt as it revolves around the sun.
...more
