The Polar jet stream is pictured in this screencap of NASA video “Aerial Superhighway”. This image portrays a zonal jet stream, with winds moving swiftly west-to-east. The fastest winds are colored red; slower winds are blue. : Courtesy NASA (National Aeronautics and Space Administration) Goddard Space Flight Center

Laura Nielsen for Frontier Scientists

In September 2012, at the end of last summer, the Arctic sea ice extent reached a record low since satellite measurements began. And, according to the National Snow and Ice Data Center, summer sea ice extent in the Arctic has declined roughly 40 percent in the last three decades.

Sea Ice Retreat in the Beaufort Sea, north of Alaska. The MODIS instrument on NASA’s Terra satellite collected these images on May 13, 2012 (top), and June 16, 2012 (bottom). The rapid melt was part of a larger phenomenon of increasing sea ice melt.: Courtesy NASA (National Aeronautics and Space Administration) Earth Observatory

The Arctic is warming faster than other parts of the planet. This enhanced warming is called Arctic Amplification. It may seem like a far-away problem to many people, yet a study led by National Oceanic Atmospheric Administration scientist James Overland, Ph.D., and published in the American Geophysical Union’s Geophysical Research Letters shows that it is a much nearer concern. Amplified Arctic warming is contributing to more frequent and more extreme weather events in North America and Europe, making the Arctic an increasingly important player in shaping regional climate in the coming century.

Climate change and Arctic warming alter the nature of the jet stream, weakening those powerful winds and changing their flow. An altered jet stream can amplify extreme weather events and change the origin, persistence, and severity of regional weather. Let’s look at why.

The troposphere is the layer of our atmosphere which lies closest to earth. Bands of powerful winds called jet streams occur in the troposhpere where areas of high and low pressure meet. When the temperature difference between the pressure fronts is particularly pronounced, the resulting winds are fiercer, and jet stream winds can exceed 100 miles per hour. The jet stream in the Northern Hemisphere is known as the Polar jet stream.

Those pressure systems are often dominated in the north by two different forces. One is known as the Aleutian Low, which is an area of low pressure centered near Alaska’s Aleutian Islands. It dominates during the winter months, and tends to generate winter storms. Then, during the summer, that low system is pushed north toward the pole by a high pressure system called the North Pacific High which is influenced more by the warmer southerly temperatures. Both systems are semi-permanent and changeable. Where the fronts meet, cold polar air interacts with the warmer air originating in the tropics and pushing north through the mid-latitudes. It is that interaction which influences weather trends in much of the Northern Hemisphere, particularly in North America and Europe.

Images illustrating the Arctic Oscillation in its positive and negative phases.: Courtesy NOAA (National Oceanic and Atmospheric Administration) & NCDC (National Climatic Data Center)

When the standard low pressure system dominates in the Arctic and a high pressure system pushes northward from the mid-latitudes, the pressure pattern is described as a positive Arctic Oscillation, during which the Polar jet stream behaves in a predictable way. Winds blow swiftly from the west to the east, pushed out of a linear path only slightly by colder low-pressure troughs sliding south and warmer high-pressure air ridges pushing north. The fast, slightly wavy, west-to-east jet stream is called a zonal jet stream flow.

In contrast, a meridional flow describes a jet stream wind that meanders far from its path, blowing much more north-to-south. Its path is more radical because low-pressure troughs and high-pressure ridges penetrate further into the opposite pressure front. The winds follow an extreme winding path, and as a result move more slowly. Meridional flows correspond with a negative Arctic Oscillation, during which a high pressure front dominates in the Arctic. Simulations run on supercomputers foretell more of those intense high-pressure systems dominating the northern Pacific and Atlantic oceans as the 21st century progresses and levels of greenhouse-gasses continue to rise.

This matters because a slow, meandering meridional jet stream can mean weather conditions are more extreme and longer lasting. Cold Arctic temperature troughs reach further south, and hot pressure ridges stab further north. Severe storm fronts often form where the pressure systems with their wild temperature gradients rub against one another. And the meridional flow can make weather conditions dominate in one region for a longer duration. No longer blowing swiftly through along a stronger zonal flow, weather trends linger and sometimes persist. It’s called a blocking pattern, and it can inflict prolonged heat spells leading to drought and increased wildfire probability, extreme summer rainfall leading to flooding, or unseasonal cold. These upsets to regional climate spell potential trouble for humans, watershed integrity for crops, and wildlife habitat.

The Polar jet stream is pictured in this screencap of NASA video “Aerial Superhighway”. This image portrays a meridional jet stream, with winds meandering more slowly, predominantly north-to-south. The fastest winds are colored red; slower winds are blue.: Courtesy NASA (National Aeronautics and Space Administration) Goddard Space Flight Center

Jennifer Francis, Ph.D., of Rutgers, names “[T]he rapid regional changes and increased frequency of extreme weather that global warming is causing,” to be a high-impact symptom of climate change. She adds: “As the Arctic warms at twice the global rate, we expect an increased probability of extreme weather events across the temperate latitudes of the northern hemisphere, where billions of people live.” The Earth is one great system, and everything is interconnected. The Arctic, though remote, impacts regional climate patterns in North America and Europe; the amplified warming occurring there deserves our attention and care.

Eyes to the north.

.

Frontier Scientists: presenting scientific discovery in the Arctic and beyond

References:

‘A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming’ John Mason, Skeptical Science
http://skepticalscience.com/jetstream-guide.html

‘Arctic summer wind shift could affect sea ice loss and U.S./European weather, says NOAA-led study’ National Oceanic Atmospheric Administration
http://www.noaanews.noaa.gov/stories2012/20121010_arcticwinds.html

‘Evidence Linking Arctic Amplification to Extreme Weather in Mid-Latitudes’ American Geophysical Union : Geophysical Research Letters
http://www.agu.org/pubs/crossref/pip/2012GL051000.shtml

‘National Weather Service Glossary’ National Oceanic and Atmospheric Administration : National Weather Service
http://w1.weather.gov/glossary/

‘Weather-Making High-Pressure Systems Predicted to Intensify’ Duke University : Nicholas School of the Environment
http://www.nicholas.duke.edu/news/weather-making-high-pressure-systems-predicted-to-intensify

Date

June 13, 2013 – 11:49AM

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Resisting change could be catastrophic, says the founder of a high-profile international think tank.

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All aboard? Broadband visionary likens the NBN to the railways. Photo: Bob Finlayson

• NBN rollout slowed amid asbestos fears

The implementation of an effective national broadband network is critical to economic development and the federal opposition must not fear it, the founder of a high-profile “intelligent community” think tank has told IT Pro.

It is not sustainable if we allow the trend to continue where people flee rural areas for economic purposes.

Louis Zacharilla

Louis Zacharilla of the New York-based Intelligent Community Forum warned that failure to make the most of implementing the NBN in Australia would be the equivalent of ignoring railways in the 19th century.

“I get the fear and the resistance,” Zacharilla co-author of Broadband Economies: Creating the Community of the 21st Century, said.

“Governments are dealing with public money and dealing with significant change. I don’t declare bad intentions for the opposition [to the NBN]. I just declare them to be a bit fearful and a little bit too cautious.

“That is natural. That is human nature. We resist change. But if you speak with anyone who has had to overcome that resistance they will say to you, this is the right way to go – we just disagree about how to get there.”

Zacharilla, whose forum anointed Communications Minister Stephen Conroy Visionary of the Year in 2012, spoke to IT Pro ahead of his address at this week’s Digital Productivity Conference in Brisbane, hosted by the Department of Broadband, Communications and the Digital Economy.

The Intelligent Community Forum releases an annual list of “intelligent communities” highlighting regions around the globe that use communications technology to effectively boost their local economies.

No Australian community has made the ICF finalist list since 2004, when Victoria made the cut.

“Australia does not lack aspiration,” Zacharilla said. “They know what is at stake. They know they should keep the talent at home, but they don’t have all the tools yet.”

ICF’s work has received plaudits from New York City mayor Mike Bloomberg and government leaders in Taiwan, France, Finland, the Netherlands, South Korea and Afghanistan.

Toronto (Canada), Oulo (Finland), and Tallin (Estonia), were among the list of this year’s top seven communities.

In implementing broadband, Zacharilla drew comparison with the economic development of cities in the US that elected to use riverboats as their main form of industrial transportation against those that saw the benefits of railways.

“Chicago, which was a backwater city, saw this thing called the railroad,” Zacharilla said. “Chicago invested in it and even today has 10 times the GDP of the state of Missouri.

“Everything is at stake [with the NBN]. This is the new railroad. If your communities are not connected to it then it is difficult to put cargo on it.”

A major focus for ICF is broadband development for rural areas. According to Zacharilla, efficient connectivity outside urban centres is a critical factor in determining wider environmental sustainability.

“It is not sustainable if we allow the trend to continue where people flee rural areas for economic purposes,” he said.

“The smaller communities will lose everything and the big cities will not be able to take the people that flood in, especially in a place like China. All hell will break loose.

“If you can keep people where they want to be, embedded in their cultures, contributing to their towns and villages, looking after their elders and learning from their elders, raising their kids in the places where they want to but can connect them to a global society through internet and broadband, then it is a win-win.” 

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BRIGHT IDEA: The new A350 Airbus long-haul carrier does a taxiing test at the aérodrome of Toulouse-Blagnac. AFP PHOTO / ERIC CABANIS Source: AFP

Flown to France this week by Airbus for the finals of the company’s prestigious Fly Your Ideas aviation design competition aimed at university students, the Royal Melbourne Institute of Technology team yesterday made their final presentation to a panel of industry experts at Airbus’ Toulouse headquarters.

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Source: Supplied

Their proposition is for a combination of LNG and sustainable bio-methane, dubbed Bio-LNG, to replace JetA1 fuel, which has the potential to reduce emissions by up to 97 per cent, depending on the mix, and slash airlines’ operating costs.

The aerospace engineering students, led by 21-year-old Luke Spiteri, also produced modelling to support the modification of existing aircraft wing tanks and the addition of underwing fuel pods to accommodate the cryogenic fuel.

“We’re very happy with how we went,” Spiteri said. “It’s now down to the judges.

“But just to be here is so rewarding. This has been an unforgettable experience.”

The group, also including Mark Spiteri, Katherine Gregoriou, Martin Burston – all 21 – and James Herringer, 24, now have to wait until Friday to see if they have beaten the four other groups from Brazil, India, Malaysia and Italy who made the finals of the competition with its 30,000 euro prizemoney.

More than 8000 students making up 618 teams from 82 countries entered this year’s competition.

Dr Graham Dorrington, the RMIT team’s academic supervisor, said if Airbus really wanted to hear about potentially “disruptive” technology – radical ideas which challenged the status quo – then he believed the RMIT students had provided it.

“If Airbus takes notice the future (of aviation) is secure,”he said.

“And what I really want is for companies back home like Woodside to take note. If we can get the industry mobilised in Australia we can be ahead of the game and there’s a lot of bloody good people working in LNG in Australia.”

Spiteri said his parents, John and Margaret of Albany Creek, were excited the team had made it as far as they had.

“They are thrilled,” he said. “They know how much work we’ve put in over the past seven months.”

The winning team will be announced at a ceremony held on Friday at UNESCO in Paris.