USU Joins NASA Cloud Study

By Greg Lavine
The Salt Lake Tribune
April 12, 2007

Clouds forming at the edge of space appear to be getting brighter and more frequent, raising questions as to their possible link to global warming. An upcoming NASA mission, with an assist from Utah State University, will send a satellite into orbit to study noctilucent clouds, which appear to glow at night.

Normally, the clouds are only seen at high latitudes, but in recent years, the evening clouds have been spotted as far south as Utah.

“We don’t know why this is happening,” said Vicki Elsbernd, NASA program executive for the $140 million Aeronomy of Ice in the Mesosphere (AIM) mission.

The launch is slated for April 25 from Vandenberg Air Force Base in California, she said during a telephone press conference Wednesday.

Elsbernd said she hopes the mission “will literally rewrite the textbook” on how the sun interacts with the Earth’s atmosphere.

USU's Space Dynamics Laboratory built an instrument that will study the ultra-high clouds, which form at an altitude of 50 miles. The lab's SOFIE, or Solar Occulation for Ice Experiment, will gather information on the particles in the clouds and the chemistry involved in forming the clouds, said USU physicist Mike Taylor, a co-investigator.

“It will tell us the amount of water that makes up the tiny ice crystals that form the clouds,” he said.

Scientists may monitor these clouds in the future as signals for climate change, Taylor said.

While astronauts on the space shuttle, as well as equipment on other satellites, have spotted the clouds, no orbiting devices are equipped to probe these clouds, said Jim Russell, the principal investigator from Hampton University in Virginia.

“We are exploring clouds literally at the edge of space,” Russell said.

Taylor is examining the link between the lower and upper parts of the atmosphere. Weather patterns can produce pressure waves, which can impact the highest reaches of the atmosphere.

Noctilucent clouds need cold temperatures, water vapor and small particles to form, Russell said. It is believed that greenhouse gases, such as carbon dioxide, at high altitudes block incoming radiation from the sun.

These gases may be lowering the temperatures at high altitudes, meaning humans may be inadvertently causing more of these clouds to form.

Russell said the satellite is scheduled to orbit for two years, and will examine the clouds in the northern and southern hemispheres.

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