03-07-2008 - Earth

sagar: Author=’Jorge Salazar’ program=’5429′ video=”Night-shining clouds – also called noctilucent clouds – are high up enough that sunlight strikes them, even after sunset. These clouds may be evidence of anthropogenic change in the upper atmosphere. (Image credit: Mika Y)Attribution Some rights reserved.Earth’s highest clouds might signal changes caused by humans in Earth’s upper atmosphere. That’s according to Gary Thomas, who works with NASA’s AIM satellite. Earth & Sky spoke to Thomas at a meeting of the American Geophysical Union.

Night-shining clouds – also called noctilucent clouds – are high up enough that sunlight strikes them, even after sunset. They’re seen at high latitudes – over Canada, for example – or the poles. The AIM satellite found that falling icy particles create these clouds. It turns out even small changes in air temperature can cause these delicate clouds to gather and dissipate.

Gary Thomas: _These clouds may be evidence of anthropogenic change in the upper atmosphere. We’ve looked at historical records, and we’re pretty much convinced that they were not around before 1885. And they’ve been growing in frequency and growing in numbers over the last 120 years._

The AIM mission also discovered what are called ice rings, high in the stratosphere.

Gary Thomas: _We saw these in our images, and these are the highest resolution images ever taken from space, of these circular, ringlike features that are hundreds of miles across._

Written by Jorge Salazar

One Response to “Private: High noctilucent clouds may signal human impact”

1. Bob says:

   January 12, 2008 at 10:27 pm

   Now this is evidence. It is small evidence but it is evidence. This the first evidence I think is good evidence of global warming.

   Reply