Polar ice clouds could be the symptoms of climate change

The wispy noctilucent ice clouds floating in the deep blue of the northern sky could be a symptom of a changing climate, say researchers from the Geophysical Institute at the University of Alaska Fairbanks.

Washington, Aug 21 : The wispy noctilucent ice clouds floating in the deep blue of the northern sky could be a symptom of a changing climate, say researchers from the Geophysical Institute at the University of Alaska Fairbanks.

"The question which everyone in Alaska is dealing with is what are the symptoms of climate change and, as in medicine, how do these symptoms reflect the underlying processes. It is believed that [these clouds] are an indicator of climate change," said Richard Collins, a researcher at institute.

Noctilucent clouds form under conditions that counter common logic. They only form in the summer, when solar radiation is most intense. This solar heating, however, rather than warming the mesopause, causes cooling.

"The mesopause region is colder in summer under perpetual daylight than it is in winter under perpetual darkness," said Collins.

Collins said the reason possibly lay in the movement of air within the atmosphere.

"Solar radiation heats the lower atmosphere, causing a rising cell of air over the summer pole. As the air rises it cools and that beats out the radiative heating," Collins said.

"Those cold temperatures allow the ice clouds to form in the mesopause. The clouds could serve as an indicator of climate change because an increase in carbon dioxide, which causes heating in the lower atmosphere, causes cooling in the upper atmosphere," he said.

The findings were presented at the Eighth International Workshop on Layered Phenomena in the Mesopause Region being held at the institute from Aug 20-23.

ANI