Knowing more about clouds in the Arctic may help to explain why climate change is warming the region twice as fast as the rest of the world, making life hard for polar bears. From ten years of observations by instruments in the north of Greenland, Sven-Erik Gryning of the Technical University of Denmark and colleagues have found that Arctic clouds do not behave as predicted by simulations, especially in spring when there are fewer clouds than expected, which affects the way that heat moves through the atmosphere.
When a cloud passes overhead on a sunny summer day, you feel colder, because the cloud blocks the sunlight from reaching you at the surface. But at night clouds act like a blanket, trapping heat released by the ground and making cloudy nights feel warmer. So understanding how clouds behave in the Arctic is important for understanding climate change there.
Measuring clouds in the Arctic is a challenge, however. The temperatures where instruments need to be deployed can be colder than the inside of your freezer (as low as -35 degrees C), and in some of the most remote locations on Earth. Only very sturdy equipment can survive these conditions, but the team's instruments have now measured Arctic clouds since 2011, using infrared beams to detect clouds overhead at two locations in the north of Greenland (see the map).
The instruments detected more clouds in autumn and winter compared with summer and spring, and in particular recorded far fewer clouds in spring than predicted by simulations of cloud cover for the region. But within each season, the amount of cloud cover varied from year to year without any clear trend, indicating a new layer of complexity for researchers trying to understand the effects of climate change in the Arctic.
This article was produced with the support and help of Dr. Jon Copley, in the framework of the COST Action training on story telling. We would like to thank Jon and the SciConnect company for the precious feedbacks and the excellent training provided to the PROBE science communication manager.
