Scientist Roberta pirazzini has set up an Arctic expedition to do something no one has ever tried before, flying a drone in the Arctic. Sensors on the drone will assess the sunlight reflected from the ice. This measurement, called surface albedo, is the key to understanding how much solar radiation the earth absorbs and how much is reflected back into the atmosphere. This is one of the scientific challenges that can be used to help predict the rate of sea ice melting.
But flying drones at the northernmost end of the earth is not an easy task. Technicians specially designed a set of precision navigation system to deal with extreme weather. The Institute also conducted months of UAV flight training for scientists. After the training, the scientists embarked on the largest Arctic expedition in history. They will take the polar stern, an icebreaker, on a one-year mission. Hundreds of researchers from 20 countries alternate on Polarstern for the mosaic mission, an acronym for the multidisciplinary drifting Observatory for Arctic climate research. Led by Alfred Wegener Institute of polar and Oceanography in Germany, it is the first expedition in modern history to spend a whole winter near the Arctic.
The budget for this task is over 1 . EUR 400 million (1 . $6.5 billion), which will last 389 days at sea. The researchers also carried a smaller practice drone that could fly in their cabins in order to keep them proficient in the weeks before they finally set foot on the ice.
Roberta pirazzini and henna reetta Hannula, scientists from the Finnish Meteorological Institute, operate UAVs in the Arctic. Soon, pirazzini encountered two major problems that have plagued Arctic explorers for two centuries: dangerous navigation conditions and operation of equipment in extremely cold conditions. UAVs and helicopters are located near the Arctic, which are affected by the extreme high latitudes. The closer to the north pole, the more chaotic the navigation. In this Arctic expedition, UAVs will be closer to the north pole than ever before. Earlier, another drone encountered navigation difficulties. The UAV took off from the ship, flew out of control, and then crashed. Pirazzini is very afraid that her albedo measurement UAV will also encounter this situation. Her fears were confirmed when she stepped on the ice. The navigation system on the drone doesn’t work, which means she and her colleagues need to manually calculate distance, direction, altitude and wind speed. “The extremely cold and harsh environment is our main enemy. There is ice not only on the rotor blades of UAVs, but also on our fingers. And it takes very fine little movements to control the UAV. When your hand freezes, you lose sensitivity and your fingers can no longer perform precision operations. ” Pirazzini said.
The fog turns into ice around the blades of the drone. Gusts of more than 8 meters per hour often ground drones. Nevertheless, the two scientists managed to make 18 flights in three weeks. Albedo measurements from pirazzini, 49, and Hannula, 33, will be analyzed to study the effects of warming temperatures on the Arctic.
The northern part of the earth’s ice sheet is warming three times faster than the rest of the earth, greatly destroying the fragile ecosystem. Arctic sea ice fell to the second lowest level on record in September, after 2012. In the first half of this year, the Siberian Arctic suffered unprecedented heat waves, and the unusually warm climate made it more difficult for the ice to re form. Arctic sea ice is currently at its lowest level at this time of year since satellite monitoring began in 1979, 37% below the historical average. Samantha Burgess, deputy director of the European Copernicus climate change service, said: “by this time of 2012, the ice has begun to thicken again. It’s not the end of the season. It may be too early to say what the impact will be, but it is likely to affect the marine food web. “
As early as August, when pirazzini went to the Arctic for UAV data collection, the Arctic sea ice had dropped to the lowest level since records began that month. These horrendously low ice sheets allow the polar stern to reach the Arctic in just six days from Norway’s Fram Strait. “There’s open water everywhere and it’s easy to get there,” pirazzini said. But if you think about the future of the Arctic, that’s not good. It’s a very fragile environment. “
On August 17, Polaris encountered low ice on its way to the North Pole. As the ice layer shrinks, measuring albedo becomes more important. The white surface of Arctic ice reflects solar radiation back to the atmosphere, while the blue surface of the ocean absorbs it. However, not all ice has the same reflectivity, and scientists are trying to figure out how much solar radiation can be absorbed by melting and diffusing ice in shallow water as the temperature rises. Although sea ice area can be monitored by satellite, other measurements that are critical to understanding the rate of melting can only be obtained closer to the ground. This more fine-grained data is crucial for determining other drivers of climate change, such as how heat is transferred to the atmosphere and water through ice.
In the past, scientists used airplanes and helicopters to get albedo readings. But UAVs have more advantages in price, and can fly in worse weather conditions, even in low clouds. Pirazzini flies between 5 and 30 meters above the ice. “UAV technology is improving every month, every year,” she said. “We are in the initial stage of this business and I believe it will expand because these measurements are necessary.”
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