At first glance, the snapshot of the week just shows some ice floes on the dark sea. But on closer inspection you can see how high-resolution these images are: the aerial photo even shows the footprints of a polar bear that had walked through the snow a short time before. Although the aerial photo was taken from a height of 100 meters, its two centimeters per pixel resolution is sharp enough to reveal even these details.
But for the scientists who take pictures like these, something else takes center stage: As part of an expedition led by the Helmholtz Center for Polar and Marine Research, they use such pictures to investigate the changes in the Arctic ice surface. With the help of two research aircraft – Polar five and Polar six – the team photographs the ice below them.
On board is the high-resolution MACS (Modular Aerial Camera System), which can be used to take very detailed photos even under extreme weather conditions. The camera makes it possible to determine the thickness of the ice edges and the roughness of ice and snow. Using near-infrared images, the scientists also detect temperature differences between the ice and its surroundings as well as freezing cracks.
Since the first flights at the beginning of September, more than 300,000 pictures have been taken. “Even with the currently very small temperature differences between water and ice, clear thermal signatures can be seen,” emphasizes Jörg Brauchle from the German Aerospace Center (DLR).
In addition, atmospheric researchers involved in the expedition are also studying the arctic air. They want to find out how clouds form over the Arctic Ocean. Because cloud formation can contribute to the warming of the arctic regions.