These polar storms can have hurricane-strength winds and are common over the polar North Atlantic, but are missing from climate prediction models due to their small size. Photo courtesy of NEODAAS Dundee Satellite Receiving Station.
Climate scientists advocate for more study of mesoscale Arctic weather systems
By Summit Voice
FRISCO — Intense, hurricane-like Arctic storms may play a bigger role in driving climate than previously thought, and most climate models have not included those effects in long-term projections, according to a new study from he University of East Anglia and the University of Massachusetts.
Adding the storms into the mix could change the long-term outlook, as the models currently may underestimate the amount of heat being transported toward Europe.
“By simulating polar lows, we find that the area of the ocean that becomes denser and sinks each year increases and causes the amount of heat being transported towards Europe to intensify,” Condron explained.
“Before polar lows were first seen by satellites, sailors frequently returned from the Arctic seas with stories of encounters with fierce storms that seemed to appear out of nowhere,” said Alan Condron, a physical oceanographer at UMass Amherst Condron,. “Because of their small size, these storms were often missing from their weather charts, but they are still capable of producing hurricane-force winds and waves over 11 meters high (36 feet).”
“The fact that climate models are not simulating these storms is a real problem … Because these models will wrongly predict how much heat is being moving northward towards the poles. This will make it very difficult to reliably predict how the climate of Europe and North America will change in the near future.”
“These polar lows are typically under 500 km in diameter and over within 24-36 hours,” said Prof. Ian Renfrew, with the Univerity of East Anglia School of Environmental Sciences. said. “They’re difficult to predict, but we have shown they play an important role in driving large-scale ocean circulation.
“There are hundreds of them a year in the North Atlantic, and dozens of strong ones. They create a lot of stormy weather, strong winds and snowfall – particularly over Norway, Iceland, and Canada, and occasionally over Britain, such as in 2003 when a massive dump of snow brought the M11 to a standstill for 24 hours.
“We have shown that adding polar storms into computer-generated models of the ocean results in significant changes in ocean circulation – including an increase in heat traveling north in the Atlantic Ocean and more overturning in the Sub-polar seas,” he said. “At present, climate models don’t have a high enough resolution to account for these small-scale polar lows.
“As Arctic Sea ice continues to retreat, polar lows are likely to migrate further north, which could have consequences for the ‘thermohaline’ or northward ocean circulation – potentially leading to it weakening.”
“Climate models are always improving, and there is a trade-off between the resolution of the model, the complexity of the model, and the number of simulations you can carry out. Our work suggests we should put some more effort into resolving such storms,” Renfrew concluded.
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