Beautiful spectacle of the rare noctilucent clouds

Noctilucent clouds is a strange atmospheric optical phenomena, very rare. It generally occurs in the summer of each year, this summer, people have taken the first batch of noctilucent clouds photo, following an up and enjoy the magic of noctilucent clouds beautiful.Every summer, residents living in high latitudes will be able to enjoy the beauty of noctilucent clouds, such as seen in this photo. Here is the Latvian capital of Riga, the photo was taken earlier this month, which is one of the sites this year's summer of the first observations of noctilucent clouds.Noctilucent clouds thin as onion skin, and therefore difficult to see during the day. Their height is very high, after the sun sets, its light is still able to irradiation in high-altitude clouds, and thus the beauty of the formation of noctilucent clouds. Noctilucent clouds by ice crystals, these rare clouds are distributed in the atmosphere in the middle layer, the height from the ground about 50 miles (about 80 km), so that they become known distribution of the maximum height of cloud in the world.

 This photo was taken on June 13, taken by astronauts on the International Space Station works. Looks from this angle, the blue luminous cloud constitute a boundary, the darkness of the space to isolate. Noctilucent clouds is also found in the southern hemisphere of the sky, but they are shooting less, which is much less the number of residents living in the southern hemisphere high latitudes sake.

 Noctilucent clouds over the town of Poland, Zubin (Szubin), there is one pair of nesting storks, photographs taken on June 17. The height of the formation of noctilucent clouds, the air density is less than 1/100 of the ground, the temperature as low as minus 200 degrees Fahrenheit (about -130 degrees Celsius).In addition, in the height, the formation of clouds the water must have been very rare. Hampton University in Virginia, James Russell (James Russell III), told reporters: "In this altitude, the dryness of the air 100 times in the Sahara desert" noctilucent clouds is difficult to see during the day and in the night, after sunset for a long time to see noctilucent clouds on a dark background showing.

This is the photographs in the United Kingdom Kendal Castle (Kendal Castle) on June 26, you can see noctilucent clouds over Cumbria, England. U.S. National Center for Atmospheric Research atmospheric chemist Dan Marsh (Dan Marsh) said, when the upper atmosphere in the extreme low temperature environment most conducive to the formation of noctilucent clouds. But the irony is that such environmental conditions in the summer. He said: "caused by the complexity of the factors this low-temperature environment in the summer." He said in a message, which involves enhanced polar air in the warmer season of upwelling. He said: "The rising air cools, so the contained water vapor will condense to form ice clouds."

After sunset on June 18, noctilucent clouds suspended over Djumala (Jurmala), in Latvia, as if a thin layer of Aurora. Although people have lived on for thousands of years near the Arctic, but the first information about the observations of noctilucent clouds record until 1885 was the first time in.

This photo was taken on June 21, Latvia Djumala over the noctilucent clouds. In recent decades, the phenomenon of noctilucent clouds seems to become more common, and even some doubt whether it is global climate change.Scientists say that this suspicion is well founded. Rising carbon dioxide levels in the upper atmosphere, it is this atmosphere region will cause more heat to space radiation, thus exacerbating the cooling rate of the air in this highly. Or cause this effect may be due to methane gas. According to the U.S. Environmental Protection Agency (EPA) data, since 1750, the concentration of such gases in the atmosphere has doubled to more than double. This rising trend is likely to start ablation is related to the deepening of the level of industrialization as well as the earlier tundra. When the methane gas to reach the middle layer below the stratosphere, this greenhouse gas will begin to decompose. Marsh said: "This results in the formation of more water vapor, these water vapor will increase the probability of the formation of noctilucent clouds." (Morrowind) Sina National Geographic News Beijing July 19, according to the report of the National Geographic website, noctilucent clouds, the is a strange atmospheric optical phenomena, very rare. It generally occurs in the summer of each year, this summer, people have taken the first batch of noctilucent clouds photo, following an up and enjoy the magic of noctilucent clouds beautiful.