News, Culture & Society

‘Freak warming’ in the Arctic stuns scientists


Buying or leasing a car in the UK? Check MOT of car before you do.

Europe has been buffeted by freezing temperatures in recent days and experts say this is the result of freak warming in the Arctic.

The Arctic is experiencing one of its hottest winters on record, with temperatures at the North Pole surging above freezing.

These unusual conditions, which scientists say have ‘never been this extreme’, are causing a disruption to the Arctic polar jet stream.

The jet stream carries winds east to west across the planet, at speeds of up to 200mph (320kph), in the upper atmosphere.

Warmer air in the Arctic has sent them off their usual course, blasting cold air over Europe – something likely to happen more often thanks to man-made global warming, researchers say.

 

The North Pole has surged above freezing despite it being the dead of winter, stunning scientists. This graphic shows global forecast system data of temperature difference from normal (in °C) on Sunday over the Arctic

On the northern tip of Greenland, the Cape Morris Jesup meteorological site has had a record-smashing 61 hours of temperatures above freezing so far in 2018.

This is linked to a rare retreat of sea ice in the Arctic winter darkness.

‘It’s never been this extreme,’ said Ruth Mottram, a climate scientist at the Danish Meteorological Institute (DMI). 

Warmth was coming into the Arctic both up from the Atlantic and through the Bering Strait, driving cold air south.

Around the entire Arctic region, temperatures are now about 20°C (36°F) above normal, at -8°C (17.6°F), according to DMI calculations.

The Arctic is experiencing one of its hottest winters on record, with temperatures at the North Pole surging above freezing. This graphic shows declining sea ice concentrations since February 20, 2018

HOW DO RISING TEMPERATURES IN THE ARCTIC CREATE COLD WEATHER IN EUROPE?

As long ago as 1973, a study suggested that an ice-free Arctic Ocean could make regions further south colder.

That ‘warm Arctic, cold continent’ (WACC) pattern is sometimes dubbed ‘wacc-y’ or ‘wacky’ among climate scientists.

When unusually warm air enters the region, it melts ice covering the waters of the Arctic Ocean.

This ice normally serves as an insulator, stopping the flow of thermal energy from the water’s surface into the atmosphere.

Without the ice in place, the oceans can transfer a huge amount of this energy into the air above.

This in turn increases air temperatures and this warm air rises up into the upper atmosphere, where it reaches the jet stream.

Jet streams are fast flowing, narrow currents of air that carry warm and cold air across the planet, much like the currents of a river.

They cover thousands of miles as they meander near the tropopause layer of our atmosphere.

The strongest jet streams are the polar jets, found 30,000 to 39,000 ft (5.7 to 7.4 miles/ 9 to 12 km) above sea level at the north and south pole.

In the case of the Arctic polar jet this fast moving band of air sits between the cold Arctic air to the north and the warm, tropical air to the south.

When uneven masses of hot and cold meet, the resulting pressure difference causes winds to form.

During winter, the jet stream tends to be at its strongest because of the marked temperature contrast between the warm and cold air.

The bigger the temperature difference between the Arctic and tropical air mass, the stronger the winds of the jet stream become.

The Arctic polar jet, which can reach speeds of up 200mph (320kph), flows over the middle to northern latitudes of North America, Europe, and Asia and their intervening oceans.

It moves from East to West, although its exact route varies and can be affected by various factors.

With the ice melt in the Arctic and the introduction of warmer air, the route of the jet stream becomes wavier and more erratic.

That means that the colder air it carries from the Arctic can penetrate further south and warmer airs from the tropics is carried further north. 

If the jet stream’s meander buckles south of the UK, it attracts cold air from the Arctic.

Conversely when it swings north, it sucks warm air from the tropics. 

To the south, a rare snow storm hit Rome on Monday and some Brussels mayors planned to detain homeless overnight if they refused shelter with temperatures set to fall as low as -10°C (14°F) in the coming week.

Hit by easterly winds from Siberia, cities from Warsaw to Oslo were colder than -8°C.

As long ago as 1973, a study suggested that an ice-free Arctic Ocean could make regions further south colder. 

That ‘warm Arctic, cold continent’ (WACC) pattern is sometimes dubbed ‘wacc-y’ or ‘wacky’ among climate scientists.

‘Wacky weather continues with scary strength and persistence,’ tweeted Professor Lars Kaleschke, a professor at the University of Hamburg.

The Cape Morris Jesup meteorological site has had a record-smashing 61 hours of temperatures above freezing so far in 2018. This graphic shows global forecast system data of temperatures (in °C) on Sunday over the Arctic

The Cape Morris Jesup meteorological site has had a record-smashing 61 hours of temperatures above freezing so far in 2018. This graphic shows global forecast system data of temperatures (in °C) on Sunday over the Arctic

Warmth was coming into the Arctic both up from the Atlantic and through the Bering Strait, driving cold air south. This is linked to a rare retreat of sea ice in the Arctic winter darkness. This image shows the current extent of sea ice in the Arctic

Warmth was coming into the Arctic both up from the Atlantic and through the Bering Strait, driving cold air south. This is linked to a rare retreat of sea ice in the Arctic winter darkness. This image shows the current extent of sea ice in the Arctic

Scientists say a long-term shrinking of sea ice on the Arctic Ocean, linked to global warming, exposes warmer water below that releases more heat into the atmosphere. This graphic shows sinking levels of ice since the 1980s

‘The question is whether this weather will happen more often. This is just one event so it’s hard to make a causal relationship,’ he told Reuters.

Scientists say a long-term shrinking of sea ice on the Arctic Ocean, linked to global warming, exposes warmer water below that releases more heat into the atmosphere. 

That in turn may be disrupting the high altitude jet stream.

‘The jet stream becomes wavier, meaning that colder air can penetrate further south and warmer air further north,’ said Nalan Koc, research director of the Norwegian Polar Institute. 

Arctic Ocean sea ice is at a record low for late February at 14.1 million square kilometres (5.4 million miles), according to the U.S. National Snow and Ice Data Center. 

That is about a million less than normal, or roughly the size of Egypt.

Erik Solheim, head of the U.N. Environment, said the rare weather fits a wider pattern driven by a build-up of greenhouse gases, mainly from burning fossil fuels from cars, factories and power plants.

The last ten days have seen a series of swings near and above freezing at Cape Morris Jesup. This graph shows Danish Meteorological Institute data showing hourly temperature reading in °C historically, in 2017 and in 2018, and on average

The last ten days have seen a series of swings near and above freezing at Cape Morris Jesup. This graph shows Danish Meteorological Institute data showing hourly temperature reading in °C historically, in 2017 and in 2018, and on average

The freak warming around the North Pole is sending a blast of Arctic cold over Europe in a sign of 'wacky' weather that may happen more often with global warming. This image shows Nasa satellite imagery of a storm near Greenland  that drew a major pulse of warm air into the Arctic

The freak warming around the North Pole is sending a blast of Arctic cold over Europe in a sign of ‘wacky’ weather that may happen more often with global warming. This image shows Nasa satellite imagery of a storm near Greenland that drew a major pulse of warm air into the Arctic

On the northern tip of Greenland, the Cape Morris Jesup meteorological site has had a record-smashing 61 hours of temperatures above freezing so far in 2018

The Cape Morris Jesup is found on the northern tip of Greenland, 442 miles (711.8 km) from the geographic North Pole

‘What we once considered to be anomalies are becoming the new normal. 

‘Our climate is changing right in front of our eyes, and we’ve only got a short amount of time to stop this from getting significantly worse,’ he told Reuters.

Under the 2015 Paris climate agreement, almost 200 nations agreed to limit a rise in temperatures to ‘well below’ 2°C (3.5°F) above preindustrial times, while pursuing efforts to limit it to 1.5°C (2.7°F).

‘The risk of an ice-free Arctic in summer is about 50 per cent or higher’ with warming of between 1.5 and 2.0 degrees, according to a leaked draft of a scientific report by a United Nations panel of scientists, obtained by Reuters.

The World Meteorological Organization said the chill in Europe was caused by a ‘Sudden Stratospheric Warming’ above the North Pole that led to a split in the polar vortex, a cold area of air above the Arctic that spilled cold south.

A big problem in figuring out whether the Arctic warmth is driven by human activities or natural variations is a lack of measuring stations. 

There are no thermometers at the North Pole and satellite measurements go back only to the late 1970s.

On the Norwegian archipelago of Svalbard, temperatures were just above freezing, with rain, and about 13.4°C (24°F) above the long-term average on Sunday.

‘There have also been recent winters with similar deviations,’ said Rasmus Benestad, senior scientist at the Norwegian Meteorological Institute.

U.S. President Donald Trump, who plans to quit the Paris Agreement, has often expressed doubts about mainstream global warming science during cold spells, such as at New Year in the eastern United States.

And Mottram at DMI said Europe’s winters had become less severe. ‘It’s not actually that cold. Its just our perceptions have shifted from a normal winter.’



Read more at DailyMail.co.uk


Comments are closed.