From now on, I’m blaming Barbara Bush... 
She’s prettier to look at!
Is it me, or does Barbara... 
and Kate Beckinsale favor each other?
Posted on 04/03/2007 10:04:27 AM PDT by Dacb
Since their discovery 120 years ago, strangely luminescent clouds called noctilucent clouds have been creeping slowly toward the equator.
Once confined to Earth's poles, the bizarre clouds have now been spotted above central Colorado, and they appear to be getting brighter and more numerous, too, said David Rusch, a University of Colorado atmospheric scientist.
This month, NASA plans to launch the $110 million AIM (Aeronomy of Ice in the Mesosphere) mission to measure noctilucent clouds and the circumstances in which they form - which may be linked to climate change.
The satellite will measure air temperature and pressure, moisture content and cloud dimensions.
Researchers at the University of Colorado at Boulder will control the satellite, process data and try to understand what some call the planet's most mysterious clouds.
Noctilucent clouds appear only at night, when their altitude - 50 miles up in the atmosphere - lets them catch sunlight no longer visible from Earth's surface, said James Russell, an atmospheric scientist at Hampton University in Virginia, the NASA mission's principal investigator.
That makes noctilucent - "night-shining" - clouds appear almost iridescent, he said. Most normal clouds are less than 10 miles up.
"They're very beautiful, they look very mysterious, but aside from all that, these clouds are changing in ways we don't understand," Russell said.
Researchers have many ideas about why noctilucent clouds may be growing in number and brightness, and most of them are related to global warming.
The greenhouse gas carbon dioxide, which warms Earth's surface, paradoxically cools the upper atmosphere, CU's Rusch said.
Noctilucent clouds - which are made of ice crystals, not water droplets - need very cold temperatures to form, he said.
In the atmosphere's coldest reaches, there's very little water vapor, a key ingredient for cloud formation, Rusch said.
Observed increases in water vapor in the atmosphere - a consequence of warming - may also make it easier for the clouds to form, he said.
Methane, another powerful greenhouse gas, may also be involved, said Scott Bailey, an engineering professor at Virginia Tech in Blacksburg, Va.
Methane's presence can increase the amount of water in the upper atmosphere, through a complicated chemical dance.
Scientists don't know enough yet to definitively call noctilucent clouds harbingers of climate change, Russell said.
"But right now, we don't have another explanation," he admitted. "We don't have enough information about them. Hopefully, in this mission, we'll be able to get it."
Staff writer Katy Human can be reached at 303-954-1910 or khuman@denverpost.com.
bump for later
They might be 50 miles up at the mid latitudes, but they are much lower at 64 north. They are so low I did not realize they actually are noctilucent clouds even though they are highly visible except in summer.
From now on, I’m blaming Barbara Bush... She’s prettier to look at!
Is it me, or does Barbara... and Kate Beckinsale favor each other?
It’s full of stars
Are you breeding your dog?
I have a male.
Don’t cross the streams!
I'd go spelunking with her
He's male, but fixed from puppy hood. He's a Schnauzer Louisiana Catahoula Leopard Dog (state dog of LA) cross. The blue eye, and/or the differing eye color probably comes from the Catahoula side. Picked him up at the Austin shelter. He had one litter mate of each sex. They were first available for adoption the day we were there, by the time we got back around after looking at other dogs, the female was gone, and while were doing the paper work, the other male came in to the office for adoption. They were really cute puppies and he's still a good looking and well mannered dog, but he's a fetching fool, he'll wear your arm out.
You forgot to mention the pony. Don’t you want a pony?
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