Looking for a specific product?

Make a search for products & suppliers, articles & news.

Warmer climate – fewer polar low-pressure systems to hit Norway

Severe storms along the Norwegian coastline and in the Norwegian Sea are often caused by polar low-pressure systems. Roughly half of all such storms have their origin in low-pressure systems formed above the sea ice covering the Arctic.

Each winter, an average of 12 polar low-pressure systems develop above the marine areas off northern Norway. These systems can move as far south as the UK.

Photo: Erik Kolstad What project researchers saw as they flew over a polar low-pressure system at an altitude of 10 000 metres. (Photo: Erik Kolstad)

Difficult to forecast

Meteorologists can predict other powerful low-pressure systems that are preceded by strong winds days in advance. But there are few early indications of the formation of polar low-pressure systems, which often develop so suddenly that ships’ crews are caught unaware, causing many shipwrecks. Both at sea and along the coastline, polar low-pressure systems often bring major snowfall as well.

In recent years, however, Arctic sea ice cover has declined, and a warming climate may exacerbate this even more. This could lead to fewer polar low-pressure systems – and fewer gale-force winds, storms and hurricanes in the northern areas.

Storms farther north

In the research project The Effect of Climate Change on Arctic High-Impact Weather Events (ArcChange), scientists studied relationships between climate change and polar low-pressure systems. The project received funding from the Research Council of Norway’s Large-scale Programme on Climate Change and its Impacts in Norway (NORKLIMA).

“We believe the frequency of polar low-pressure systems heading toward Norway will drop. As the extent of sea ice declines in the Arctic, the low-pressure systems should move farther north, missing the Norwegian mainland more. Svalbard, however, may be hit by polar low-pressure systems in the future,” explains Researcher Øyvind Sætra of the Norwegian Meteorological Institute.

Photo: ArcChange A polar low-pressure system seen from the ground. (Photo: ArcChange)

Arctic cyclones

Polar low-pressure systems form when extremely cold, dry Arctic air is carried from ice-covered polar regions and across warmer ocean surfaces. The temperature gradient between the air and water can reach up to 20°C – a temperature shock that creates atmospheric chaos and forms an Arctic cyclone, similar to but smaller than its tropical cousin.

There are forces constantly at work to equalise the difference in temperature between water and air. Vast amounts of energy escape the ocean in the form of heat within water vapor – enough, in fact, to power a cyclone.

Energy from the ocean

The ArcChange project has given researchers a whole new level of understanding about how the ocean supplies the energy for polar low-pressure systems. Knowledge about the dynamics of heat energy transfer from marine waters to the atmosphere is vital to international climate research.

During the project, researchers isolated the various physical processes of a polar low-pressure system. This has led to a better understanding of the role of factors such as waves and wind in the development of a cyclone.

Photo: Wikimedia Commons Notice the cyclone shape as a polar low-pressure system hits the coast of Finnmark, Norway’s northernmost county. At the top of the photo, the southern tip of Svalbard is visible. (Photo: Wikimedia Commons)

Wind is to blame

By dropping a total of 147 sondes (atmospheric sensors) into a cyclone from an altitude of 10 000 metres, the researchers were able to map the entire two-day progression of a polar low-pressure system. The team created a three-dimensional depiction of the pressure system; this data could prove valuable in future research.

“A common hypothesis,” says Dr Sætra, “has held that preceding the formation of a polar low-pressure system, the air down near the marine surface amasses huge amounts of what we geophysicists call CAPE (convectively available potential energy). But we found no such CAPE when we released our sondes to float down through the storm, so we have now concluded that it must be the wind that whips up the entire energy transport from the ocean to the air.”

Warmer ocean temperatures not a factor

Until now, many climatologists have believed that global warming and higher ocean temperatures would cause the transfer of more energy from the water to the atmosphere, stirring up higher winds and more storms.

The ArcChange researchers believe that higher marine temperatures have practically no impact on polar low-pressure systems, because in a warmer climate the atmosphere is warmed more quickly than the water. Thus the temperature gradient between the ocean and atmosphere would be more likely to decrease rather than increase.

The ArcChange project
The ArcChange project was a collaboration between scientists from the Norwegian Meteorological Institute, the Department of Physics and Technology at the University of Bergen, and the Bjerknes Centre for Climate Research in Bergen.

 

 

 

Related news

Latest news

BP Awards Schlumberger Contract for Mad Dog 2 Project

Export Conference 2017: A changing world

Register for this year’s most important conference for Norwegian exporters. We can promise you an interesting and inspirational day!

Meet Elkem Silicon Materials at the Ceramics Expo 2017

Elkem Silicon Metrials invites to meet their team at the Ceramics Expo 2017. This is North America’s largest, free-to-attend exhibition for Ceramic manufacturing and applications.

Event - TechnipFMC at Gastech April 4

Most ship owners are now looking very closely at the benefits that digitalization can bring in operational gains.

Deepocean Awarded Surf Contract from BP for the Foinaven Field

DeepOcean today announced that it had received a call-off under its new Master Service Agreement (MSA) with BP Exploration Operating Company Ltd.

Parquet Floor - a Furniture in itself

Read how a Nordic style, maintenance free new floor is a furniture all in itself. 

Haavik in as Sales Director

Tor Henrik Haavik enters the role as Sales Director in Steinsvik AS. Haavik has an engineering education from Høgskolen i Haugesund and has been employed in Steinsvik since 2002. Haavik comes from the position of Sales Man...

Powder Characterization Experts Offer Solutions to Optimize Process Performance

Freeman Technology, the powder characterization specialists, will be exhibiting at the Ceramics Expo for the first time (25 – 27 April, Cleveland, OH, USA). The company offers material characterization solutions aimed at o...