Frigid temperatures make the Arctic an extreme environment in and of itself. But a changing climate and a still incomplete understanding of the region are adding new phenomena and unpredictability to the mix. We already know that thawing permafrost and retreating sea ice are affecting the region’s weather. Other changes are harder to see, but their impact may be just as great
Extreme marine storms appearing in the Arctic and Southern ocean, also known as polar lows, are short-lived atmospheric low-pressure systems. They last for up to two days, producing strong winds over the areas of about 1,000 square kilometres and causing rogue waves, uncommonly large and dangerous waves that appear suddenly on open water and pose a threat to ships. One polar low occurring between Jan Mayen and eastern Greenland in 1952 led to one of the worst shipwrecks in Norwegian history.
In the Arctic, polar lows originate around 40° North and in the Antarctic around 50° South. They can be formed under a number of different conditions, such as when cold air meets warm air, and they are associated with snow squalls. Polar lows frequently develop close to where sea-ice meets open water, as well as along snow-covered shorelines.
Simulations of how the atmosphere functions helps to improve our understanding of polar lows; but predicting them is still elusive. As a result, polar lows hinder development of off-shore oil and gas projects in the Barents Sea and complicate the logistics of shipping activities along the Northern Sea Route, a Russian-controlled shipping lane. Given their relatively limited expanse and the short amount of time they exist, forecasting them in a manner that is useful for many commercial activities in the North poses something of a challenge.
According to the World Meteorological Organisation, a UN body, lightning is one of the more serious changes being seen in a warmer Arctic. It is caused by warm, humid air, and, decades ago, thunderstorms were believed to be rare over the Arctic Ocean; when it did occur, it was restricted to “infinitesimally small areas”. Nowadays, lightning is frequently observed in the polar regions. Recent observations at meteorological stations located above 60° North have shown an increased number of thunderstorms in interior Alaska, north-western Canada and much of Siberia and European Russia. Severe thunderstorms above 70° North over the Canadian Arctic Islands were recorded for the first time in 2014. The 2021 Lightning Density Map, produced by Vaisala, a Finnish firm, shows drastic growth in the number of lightning strikes above 80° North, with the furthest north recorded just 52 km from the North Pole.
Fog is another significant challenge to commercial activities in the Arctic. There are several reasons why fog is being observed more frequently, but one of them is the rapid retreat of sea ice. The larger areas of open water allow for greater heat and moisture exchange between the atmosphere and the ocean. Ground and satellite observations help to monitor changes in the Northern environment. Using simulations, scientists are able to foresee some of them, and they have recorded an overall reduction in visibility of between 8 % and 12% so far this century. Studies show it may cause significant risks to vessels navigating the Arctic waters in the near future.
Weather patterns originating from the other parts of the planet also have a growing impact on the polar regions. Strong and frequent cyclones, El Niño and atmospheric rivers, to name a few, all have consequential effects on the Arctic. The El Niño-Southern Oscillation, the irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, contributes to pan-Arctic warming through what is called the ocean-wave effect.
Scientists have also found that tropical Atlantic hurricanes are able to reach the Arctic Ocean, and that they have an impact on atmospheric circulation in the North. Cyclones that form at middle latitudes have a long range of effects on the polar regions, including creating what is known as atmospheric rivers, corridors of water-vapour stretching towards the North Pole, that modulate polar hydroclimate and amplify Arctic warming.
Weather forecasting is a complex process. Modern technology has helped us to gather massive amounts of information about atmospheric phenomena. We understand some interactions between large weather systems and local changes in the polar regions, but scientists will need more time to understand climate sensitivity in detail. They reckon that climate change will make some types of extreme weather events more frequent, more intense and more damaging. And that would make it more difficult for climatologists to forecast future weather.
Ekaterina Uryupova is a senior fellow at the Arctic Institute. She is an environmental scientist who has worked in the polar regions as a researcher and guide. Her areas of expertise include climate change, marine ecosystems, fisheries and environmental policy.
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