Scientists searching for bad weather

From February 25 to March 16, scientists stationed at Andøya has flown over the Barents Sea in search of bad weather. The results will be used to prepare weather models so that meteorologists will be able to provide more precise forecasts.

The bad weather that rages from time to time off of the Norwegian coast is so intense and localized that it is not possible to study by ship. Thus the scientists have been using a Falcon plane equipped with instruments that can measure what is happening inside a polar low pressure system or an Arctic front. They also measured several layers of atmosphere over large areas.

"The bad weather in the north is not necessarily worse than the bad weather in southern Norway, but it is far more difficult to forecast. Arctic fronts and polar low pressure systems are so small that they are not always captured by models and satellite pictures. In addition, we have a very fragmented observation network in the northern regions," explains Jon Egill Kristjansson, who heads the research project IPY-Thorpex. 

Less accidents
Extreme weather in the north can have significant consequences for those in the fishing industry. In 1974, 36 fishers were killed when the fishing vessel Gaul disappeared in a storm off of Nordkapp. And there are many indications that the Mehamn accident in 1982 was caused by the strong winds that result from cold air meeting high mountains.

The oil and gas platforms off the coast of Finnmark may become vulnerable to extreme weather as the activity on the continental shelf increases. And in a warmer climate, the shipping traffic from Asia through the Northwest Passage will increase. These ships could end up sailing through seas where polar extreme weather frequently rages.

Foto: IPY-Thorpex/ Gudmund Dalsbø
DLR Falcon. Polart lavtrykk i bakgrunnen. Foto: IPY-Thorpex/Gudmund Dalsbø

Better models
Observations from the expeditions at Andøya will be used by scientists participating in the project to fine-tune existing forecasting models. At the same time, data from some of the instruments have been used to forecast weather while the mission was being carried out.

"We are very excited about what these readings will tell us," says Jon Egill Kristjansson.

"Flying into various weather phenomena and gather high-quality data gives us a lot of information about extreme weather in the Arctic, and we can discover connections we were unaware of and thus make better weather models."

Cutting edge technology
Monitoring and measuring extreme weather demands extended use of high end technology. One of the crucial technologies that made the IPY-THORPEX project possible is called lidar, and can be described as the laser version of the radar.

LIDAR (Light Detection and Ranging) is an optical remote sensing technology that measures properties of scattered light. While the radar transmits radio-signals, the lidar transmits laser signals.

"This technology was absolutely crucial to the project. Together with the other instrumentation in the aircraft, the lidars secure the quality and precision of the data, and thus our analyses and models", said Kristjansson.

In the IPY-THORPEX-project, the scientists used two different types of lidars: wind and water-vapour lidars. In combination with dropsondes and the turbulent flux probe on the Falcon aircraft, the lidars provide information about wind-speed, wind-direction, and humidity.

Read more about the LIDAR-technology here.

Many different types of bad weather
The scientists have studied three phenomena that create extreme weather along the Norwegian coast: Arctic fronts, polar low pressure systems, and strong winds caused by high mountains and cold air. The winter months are peak season for this kind of bad weather, thus the scientists planned the mission for February and March because of the light conditions.

Foto: Foto: IPY-Thorpex/Gudmund Dalsbø
Jon Egill Kristjansson

"It makes all the operations much easier to carry out, including being able to see a lot of interesting things out of the airplane window. We were able to take a lot of instructional photographs of interesting phenomena, and use satellite pictures with visible light, and not just infrared pictures," explains Kristjansson.

An Arctic front is the wall that is created when milder air meets ice-cold air cooled over the polar ice in the north. This front can extend up to 500 kilometers, and can result in extreme winds up to hurricane strength and heavy precipitation.

Polar low pressure systems are created when cold air from the ice-covered areas in the north move south and meet warm oceans. This pumps enormous amounts of heat and moisture from the sea into the atmosphere. The Norwegian coast is particularly vulnerable because it is so close to the edge of the polar ice, at the same time that the Gulf Stream carries warm seawater northward along our coast.

The DLR Falcon
The research plane DLR Falcon is owned by Deutsche Forschungsanstalt für Luft- und Raumfahrt, the German aerospace center. The plane, originally produced for the private market, is extremely robust and constructed to be able to fly through hurricanes just as easily as 30 meters behind the jet motor of a passenger plane.

The plane can carry 1500 kilos of instruments, including the weight of the three people there were room for on board. During the three weeks that the plane was stationed on Andøya, it was in the air a total of 50 hours spread out over 15 expeditions. The area that was studied ranges from Nordland to Svalbard in the north, to the Russian border in the east, and to Iceland in the west.

On board the plane were instruments that can measure temperature, humidity, air pressure, wind strength, and turbulence. These readings was taken at least once per second to capture all the variations. 

The plane also released a total of 150 sondes that measured temperature, humidity, air pressure, and wind strength. The sondes have been used to feed meteorlogists all over the world weather forecasts during the mission

Drones used
In addition to the German plane, two drones  examined the atmosphere in Framstredet west of Svalbard.

The unmanned planes were rented from the research institute Norut in Tromsø and the University of Braunschweig in Germany. They weigh only 12 kilos, and travel about 100 kilometers an hour, with a range of about 300 kilometers. They were equipped with instruments to measure temperature, humidity, air pressure, and ocean-surface temperature.

The coast guard participated
The coast guards from both Svalbard and Senja have had Thorpex scientists on board during the project. The coast guard vessels has released radio sondes into the atmosphere to measure temperature, humidity, air pressure, and wind strength.

In addition, Russian scientists took readings of the atmosphere over Novaja Semlja, Murmansk and Franz Josef Land using balloons, while Norwegian weather observers released balloons from Bjørnøya, and German scientists from Ny Ålesund.

About the scientists
About 25 scientists lived and worked on the Andøya Rocket Range from February 25 to March 16.

"It takes a lot of planning to find out where we will fly. Much of the time are spent planning the next day's flight and directing the plane toward areas with bad weather while it is in the air," says Kristjansson.

Read more on IPY-Thorpex own pages

Top photo: polar low pressure seen from the inside. Photo: Erik Kolstad.