High noctilucent clouds may signal human impact
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.
Additional Teacher Resources
NASA: Homepage for NASA AIM Satellite Mission
Includes information on launch coverage, images, news, facts, and more.
NASA Satellite Captures First View of Night-Shining Clouds
This NASA article describes noctilucent clouds and provides images of them. A satellite named AIM is dedicated to the study of these clouds. Scientists state that little is known about how these clouds form and why they are being seen more frequently. AIM principal investigator James Russell III stated that 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.
NASA – AIM: Exploring Clouds at the Edge of Space
This website provides information for teachers, students, and scientists on a NASA study of noctilucent clouds and AIM satellite data. Click on the Education box on the top bar to access lesson plans, PowerPoint presentations, and more.
