A group of scientists currently on campaign in Finland have made their first autonomous landing with a weather sensor drone. This marks a revolution in the process of automating meteorological data retrieval.
Known as a SUMO (Small Unmanned Meteorological Observer), the weather drone can be used multiple times. This is in contrast to traditional weather balloons which can only be used once, cost nearly USD$400 each, are packed with radio probes, and often the disappear with the wind and get lost.
Professor of Experimental Meteorology at the Geophysical Institute of Bergen University, Joachim Reuder, spoke to Finnish tu.no, adding, “We are not so often interested in what happens in the highs up to 25 kilometers, as far as the radio channels ranges, but only the lower one to two kilometers. Then we will send a SUMO.”
The difference in cost does not matter, as he explains. “After around 15 flights it will be cheaper than with the weather balloons,” explains Reuder.
In a three-week campaign in France, they conducted 200 measurements with three SUMO flights to 1600 meters in height. The three planes they used during the campaign in France cost much less than it would cost to use weather balloons.
Reuder is currently in Finland on a major international campaign, with researchers from Bergen, Finland, Germany and the United States. They have been in the northern part of the Baltic Sea for a month, on a small island about 20 kilometers west of the city of Oulu, gathering as much meteorological information as possible.
By collecting data on wind conditions and temperature, they hope to understand the turbulent exchange processes in the atmosphere near the ground.
“Forecast models still have significant problems of predicting ground temperatures in very cold conditions,” says Reuder, adding that the reported temperature of the models is usually correct at 10 to 20 meters above the ground.
“But if you leave the house in the morning, it can easily be 10 to 15 degrees colder. It is precisely this cooling – in the last few meters – that the models so far do not provide. Here we hope to improve the way turbulence is treated in the numerical models, to get the last bit right, or at least better,” he says.
The SUMO, which looks like a small aircraft, has sensors for temperature, humidity and wind, and can also measure air pressure and temperature on the surface via infrared measurement.
Developed in partnership with Paparazzi, an open source code community for drone hardware and software project for autopilot systems and base station software for everything from multicopters to hybrid aircraft, the micro plane can fly predefined routes, which can be changed at any time via a two-way data link.
“Only the launch and landing is usually done manually, but can also be automated,” says Reuder.
Theoretically, the plane can go as high as 5 kilometers, but Reuder says it’s actual maximum is limited by regulation.
“But, of course, it depends on the flight permit we can get. Here in Finland we have blocked airspace that we can operate up to 1900 metres above the ground or the sea,” he says.
And while the use of drones is revolutionising Finnish meteorology, it does not mean that they have put the weather balloons on the shelf.
“No, the weather balls still exist and they are still very important. Mainly because they reach altitudes up to 20 or 25 km. And it is important entry information for all weather forecast models.”