Wednesday, December 12, 2007

Mysterious Clouds More Common Due to Climate Change?

Night-shining clouds are seen over Finland in this undated photo. Scientists say such clouds are appearing brighter and more often and that human-caused climate change may be the cause.

Mysterious "night shining clouds," that in view of the polar sky, the bright and frequently in the last few years, and climate change, the offender, scientists announced on Monday.

So-called noctilucent clouds, the stripes across the sky in vivid colors in the polar summer, ten times brighter than previously thought, according to recent data from NASA's Aeronomy of Ice in the Mesosphere (AIM) satellite.

The data collected during two polar cloud seasons, beat the formations appear daily, are widespread, and have begun, in the form of lower margins than before.

Canary climate change

Night illuminating clouds are mostly of ice particles in the water vapor condenses on atmospheric dust.

The AIM mission is the first detailed examination of the clouds that are about 50 miles (80 km) above Earth's surface - "literally at the edge of space", AIM Principal Investigator James Russell III said yesterday at a press conference at the American Geophysical Union fall meeting in San Francisco, California, USA.

The air there is more than one thousand times drier than the Sahara, and the temperature drops to minus 235 degrees Fahrenheit (minus 148 degrees Celsius) - ideal conditions for the creation of clouds.

A declaration is expected for the clouds' increase is that the temperatures in the upper atmosphere have become even colder by the construction of carbon dioxide in the atmosphere, says Russell.

Annual emissions of carbon dioxide levels have been about 20 percent since 1990. Most scientists agree, is the formation of the climate change and the heating surface.

In the upper atmosphere, carbon dioxide is not acting like a thick, heat-trapping blanket.

Instead, it forms a thin layer, to escape the heat, the temperatures drop and ice particles to form.

"[The] cloud is the mine's canary of global warming," said Russell National Geographic News.

No Other Plausible Reason

The evidence that carbon changes in the night sky illuminating is still hesitant, said Russell.

But, "quite frankly, we do not know of other plausible reasons why it is not global climate change," he said.

"If this is true, who says we are not only changing the atmosphere in which we live, we are changing a very remote, rarified part of our atmosphere."

Such profound change means that "we need to be," says Russell.

"If [the cloud changes] are, in fact, carbon dioxide to build, here is another reason that we confirm, it should strive to do something about this."

"Exquisite thermometer"

AIM also discovered "dramatic changes" in the cloud behavior, "says Scott Bailey, AIM Deputy Principal Investigator.

The data suggest that the clouds are very variable, rotating every five days after minute shifts in the temperature-even as little as 5 degrees Fahrenheit (2.7 degrees Celsius).

"These clouds are noble thermometer," he said.

"Now we are in a position to the entire life cycle [a cloud] for the first time," Bailey said National Geographic News.