2007-06-29

News: First images of noctilucent clouds from space

A view of the North Pole. White and light blue represent noctilucent cloud structures. Black indicates areas where no data is available.
Credit: Cloud Imaging and Particle Size Experiment data processing team at the University of Colorado Laboratory for Atmospheric and Space Physics


These are the first images of noctilucent clouds from space.
The first observations of these "night-shining" clouds by a satellite named "AIM" which means Aeronomy of Ice in the Mesosphere, occurred above 70 degrees north latitude on May 25. People on the ground began seeing the clouds on June 6 over Northern Europe. AIM is the first satellite mission dedicated to the study of these unusual clouds.

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 Northern Hemisphere’s summer season which began in mid-May and extends through the end of August and are being seen by AIM’s instruments more frequently as the season progresses. They are also seen in the high latitudes during the summer months in the Southern Hemisphere.
This is basic research in earth science. One thing is already known: the clouds are changing.
Very little is known about how these clouds form over the poles, why they are being seen more frequently and at lower latitudes than ever before, or why they have been growing brighter. [emphasis added] AIM will observe two complete cloud seasons over both poles, documenting an entire life cycle of the shiny clouds for the first time.

"It is clear that these clouds are changing, a sign that a part of our atmosphere is changing and we do not understand how, why or what it means," stated AIM principal investigator James Russell III of Hampton University, Hampton, Va. "These observations suggest a connection with global change in the lower atmosphere and could represent an early warning that our Earth environment is being changed."
PMCs occur 50 miles/80 km above Earth’s surface. This is at the top of the mesosphere. It's almost at the thermopause, the boundary between the mesosphere and thermosphere. In the United States, if you travel to this height, you're considered an astronaut. Just above this is where auroras form. Far below,
at 15-35km altitude, in the stratosphere, is the famous ozone layer.

We are so screwed.

4 comments:

Larry said...

Thanks for posting this fascinating image, Xris!

Ki said...

Wonderful eerie and beautiful image. I wonder if they're not closely related to the auroras - just the change in atmospherics. A different component of the solar wind exciting certain molecules existing at a specific height?

Xris (Flatbush Gardener) said...

Larry: Isn't it beautiful? I was going to post about this even without the image. But when I came across it while researching this project, I knew that was the one.

Ki: These clouds are really high, the highest clouds in our atmosphere. Weather balloons can't reach them, because the atmosphere is so thin. The auroras form just above these clouds. I'm sure that determining whether or not there are connections between the two phenomena and, if so, what they might be, are among the questions the team scientists hope to answer.

lisa said...

Thanks for this post! I'd never heard of such a thing, and while I don't want to, I tend to agree with you-we ARE screwed!