The images captured by Nasa's AIM probe show clouds that shine in the night. This is a new phenomenon. The clouds look like thin stretches of irradiescent cotton wool. They hover around 50 miles above the ground. The twilight clouds are increasing in frequency. Also they're getting more and more stretched out, scientists say. They are bepuzzled as to why it is that the clouds "alter rapidly, hour by hour and day by day", the BBC reports.
"These are things we don't understand and they all suggest a possible connection to global change; and we need to understand that connection and what it means for the whole atmosphere," dr James Russell told BBC News
He heads up the Aeronomy of Ice in the Mesosphere (AIM) mission. The clouds are big chuncs of ice. They are generated only in cold temperatures and consist of water vapour and small dust particles.
Dr. Gary Thomas, a colleague of Dr Russell said that the AIM team is studying massive rings in the clouds which despite their big size are extremely variable. "In just a few minutes, these holes are gone and others can appear. And some of these rings are huge - 300-400 miles across," said Thomas.
The scientists are studying the permanent footage from their probe to see what it is that triggers the change. Prime suspect is global warming. The scientists say that the clouds' behavior is altering due to a vital change in the climate's basic make up. It is a change that only has occurred in the last few years.
The NASA space craft has been launched only in April this year, so the research is relatively young. But the scientists say they're on their way to discover the main reasons.
One big clue they revealed is that temperatures are the main factor into the clouds' formations. AIM images seem to indicate that the clouds hover around the Arctic for about five days before they dissolve. The scientists refer to this as a 'rotation in longitude'. This movement is reflected in the temperature data.
"The interesting thing is that the magnitude of the temperature changes is only about five degrees Fahrenheit (3C)," said Dr Scott Bailey, AIM's deputy principal investigator from Virginia Polytechnic Institute and State University.
"So, a very small change in temperature leads to a dramatic change in cloud behaviour. We conclude from that that these clouds are a very sensitive measure of temperature change."