Very important research has just confirmed what the Alaska Progressive Review has been noticing, and been commenting on for some time. That extreme weather events are increasing across the globe, including here in Alaska. Many of which are being caused by changes in the jet stream leading to stronger, but slower-moving, and sometimes stationary, high pressure ridging episodes. Before we look at that though, we need to review some concepts, so that everyone understands exactly what is taking place. Because this is our future, scientifically confirmed.
First, what is Arctic Amplification? It refers to the fact that as the global atmospheric/oceanic system continues to warm due to the increasing levels of atmospheric CO2 and Methane from fossil fuel combustion, warming in the Arctic region is much greater than in lower latitudes. Due to changes in snow/ice cover extent and duration.
This is also occurring on the fringes of Antarctica, but because of it's much greater extent of ice/snow cover and high elevation, not as much in it's interior, so far.
Second, it's important to have a good understanding of how the global atmospheric circulation works. This little video is a model re-construction of an actual daily satellite composite of the western hemisphere, showing the different flow regimes, from the equatorial regions, to the higher latitudes.
http://serc.carleton.edu/eslabs/weather/3a.htmlVideo courtesy of NASA/Goddard Space Flight Center
Linked below as well, is a larger actual loop of infrared (IR) satellite images from the GOES east satellite, that sits over the equator and is one of two US satellites so configured, to remain over the same spot and provide continuous imagery 24/7, which is a primary tool for weather forecasting. Other countries have similar satellites focusing on their area of interest.
What are these showing us?
In a nutshell, the global atmospheric circulation is driven by the large-scale temperature differences between the equatorial and polar regions. Which exist because the sun is more directly overhead throughout the year in the tropical and subtropical regions, heating the continents and oceans much more than further toward the poles. Of course the fact that the Earth "wobbles" 23.5 degrees from the vertical on it's axis as it circles the sun drives the seasons, as portions of the globe are either tilted toward or away from the sun. But even with that, the overall solar energy inputs to the regions within 30 degrees either side of the equator are much greater than those further north or south. In fact, at our latitude here in Anchorage, AK (61N), from about early November, until roughly early February, more heat is lost through infrared radiation to space, than gained from the sun. Because of the low solar angles then.
On a stationary globe, what would end up existing, with the strong temperature gradients from the tropics to the poles, would be a giant circulation of rising air (because of the strong surface heating) over the tropics, with descending air in the polar regions. But because of the Earth's rotation, this simple circulation pattern breaks down roughly at latitudes between 20-35 N or S. And what we end up with is what you see in the image below, or in the satellite loops.
The Mid-Latitude cell on the above image corresponds to the area of the "jet stream", where high and low pressure systems meander around the globe, in a westerly overall direction (aided by the Earth's rotation), but with significant buckling toward and away from equatorial regions. These jet stream winds are strongest generally between 8000-11000 metres, but in weather forecasting several different atmospheric levels are used to track the features in the "jet stream" that drive the weather in the middle and higher latitudes. Here in the northern hemisphere, jet stream flow from the north drives colder air south from the polar regions, and from the south, warm air north from the sub-tropics.
Well, what we have been noticing over the past 10-15 years especially (since your lead editor has been a professional operational meteorologist since 1986), is that jet stream flows over western North America (since that is where I have been working) from the south, associated with upper-level high pressure ridging, have been getting stronger and often more slowly moving. So if you are in an area stuck under a stronger, more persistent high pressure ridge for weeks, or months, then generally speaking, much warmer, drier weather will result. A primary example being the US midwestern heat/drought (which still continues) of the previous spring/summer.
But if you are in an area ahead of or behind one of these slowly-moving or stationary high pressure ridges, under then overall low-pressure troughing, cooler, wetter weather will result. And depending on the exact area and pattern configuration, very adverse weather with flooding/heavy rainfall, or in winter, heavy snowfall, can result.
An excellent example of this here in South-Central Alaska was our truly dreadful month of September 2012, this past year.
A month that brought us just slightly cooler-than normal temperatures, but heavy rainfall, nearly double the average monthly amount, here in Anchorage. Punctuated with four low pressure systems/frontal passages that brought strong winds, the worst being the damaging storm of 9/04. Because S-Central Alaska was stuck in a pattern where strong southerly jet flow prevailed between colder upper low pressure to the west, and the strong ridging over the BC/WA/OR coasts. This strong south flow historically has been focused further south on the average, bringing heavy SEP/OCT climatologically expected rains from low pressure systems to SE Alaska. The enhanced west coast ridging forced this pattern north at times directly into S-Central Alaska in Sept. 2012. SE Alaska did receive it's climatologically "normal" rains in Sept., but further south in coastal BC Canada, it was much drier than average.
This picture, above, was during one of the weaker September storms, when winds at this time were probably gusting to 110 kph (67 mph) or so. Below, the North Fork of Campbell Creek was flowing at least three times larger than usual, toward the end of the month, at the end of a dreary 3-day "atmospheric river" rain event.
I had to make sure our research assistant Kluane didn't try and cross the raging middle portion of the creek. Mattie knew better. The little foot bridge crossing the creek was partially washed away, but some helpful souls, who remain anonymous, rebuilt it even better and stronger than it was afterward. Thanks to you all, whoever you are!
Whilst we were engaged in our September to forget, here in South-Central Alaska, downstream, jet-stream-wise, Northern California, Oregon, and Washington had an unprecedented nearly rainless month! September usually marks the time of the first of the fall rains returning in northern California, while further north in OR/WA, rains typically increase, as the jet stream usually begins to strengthen and dip a little further south. Not in September 2012! In fact, whilst visiting family in Oregon in early October, I was struck by the dry, desolate conditions in the Willamette Valley. Smaller trees and shrubs, coated in dust, were wilting from the drought. Fall rains didn't begin until mid-October, even in Oregon. Why? Stronger than average, persistent (slowly-moving) high pressure ridging along the west coast extending up into southern British Columbia, Canada.
Below are a few other articles the Alaska Progressive Review has presented on our changing climate due to global warming, and the effects we are seeing, locally and globally. Feel free to peruse these if you have the time.
OK, researchers in Europe are now able to scientifically model/describe why these kind of weather patterns (and many that are much worse) are occurring. Here is an article presenting their information, with a few comments from us for clarification.
http://www.redorbit.com/news/science/1112791761/weather-extremes-due-to-atmosphere-wave-patterns-022613/
Wave Patterns In The Atmosphere Help Explain Weather Extremes
February 26, 2013
Image Credit: Photos.com
April Flowers for redOrbit.com – Your Universe Online
In recent years, the world has suffered from severe regional weather extremes such as the heat wave in the US in 2011 [and 2012, eds], or the one in Russia in 2010 that coincided with an unprecedented Pakistan flood. There is one common physical cause behind these individual events, according to a new study from the Potsdam Institute for Climate Impact Research [PIK].
The findings of the study, published in Proceedings of the National Academy of Sciences [PNAS], suggest man made climate change repeatedly disturbs the patterns of atmospheric flow around the globe’s Northern hemisphere through a subtle resonance mechanism.
“An important part of the global air motion in the mid-latitudes of the Earth normally takes the form of waves wandering around the planet, oscillating between the tropical and the Arctic regions [the jet stream, eds]. So when they swing up, these waves suck warm air from the tropics to Europe, Russia, or the US, and when they swing down, they do the same thing with cold air from the Arctic,” explains Vladimir Petoukhov.
“What we found is that during several recent extreme weather events these planetary waves almost freeze in their tracks for weeks. So instead of bringing in cool air after having brought warm air in before, the heat just stays. In fact, we observe a strong amplification of the usually weak, slowly moving component of these waves,” says Petoukhov.
The study shows time is critical to this process. Two or three days of 86-degree Fahrenheit weather are no problem, but twenty or more days lead to extreme heat stress. prolonged hot periods can result in a high death toll, forest fires, and dramatic harvest losses for the many ecosystems and cities not adapted to such temperatures.
Global warming caused by greenhouse gas emissions from burning fossil-fuels is not uniform. In the Arctic, for example, the relative temperatures, amplified by the loss of snow and ice, is higher than on average [Arctic Amplification, eds] . As a result, the temperature difference between the Arctic and, for example, Europe is reduced, yet temperature differences are a main driver of air flow. It should be noted that continents warm and cool more readily than the oceans.
“These two factors are crucial for the mechanism we detected,” says Petoukhov. “They result in an unnatural pattern of the mid-latitude air flow, so that for extended periods the slow synoptic [the larger-scale "long-waves", eds] waves get trapped.”
To describe the wave motions in the extra-tropical atmosphere and show under what conditions those waves can grind to a halt and become amplified, the team developed equations which were then tested using daily standard weather data from the US National Centers for Environmental Prediction (NCEP). The trapping and strong amplification of particular waves – like “wave seven” (which has seven troughs and crests spanning the globe) – was observed during recent periods of major weather extremes. The data collected by the researchers show an increase in the occurrence of these specific atmospheric patterns, which is statistically significant at the 90-percent confidence level.
“Our dynamical analysis helps to explain the increasing number of novel weather extremes. It complements previous research that already linked such phenomena to climate change, but did not yet identify a mechanism behind it,” says Hans Joachim Schellnhuber, director of PIK. “This is quite a breakthrough, even though things are not at all simple – the suggested physical process increases the probability of weather extremes, but additional factors certainly play a role as well, including natural variability.”
The project spans a 32-year period, which provides a good indication of the mechanism involved, yet is too short for definite conclusions.
The study significantly advances the understanding of the relation between weather extremes and man made climate change, however, surprising the scientists with how far outside past experience some of the recent extremes have been. The emergence of extraordinary weather is not just a linear response to the mean warming trend, the study shows, suggesting the proposed mechanism could explain that.
In recent years, the world has suffered from severe regional weather extremes such as the heat wave in the US in 2011 [and 2012, eds], or the one in Russia in 2010 that coincided with an unprecedented Pakistan flood. There is one common physical cause behind these individual events, according to a new study from the Potsdam Institute for Climate Impact Research [PIK].
The findings of the study, published in Proceedings of the National Academy of Sciences [PNAS], suggest man made climate change repeatedly disturbs the patterns of atmospheric flow around the globe’s Northern hemisphere through a subtle resonance mechanism.
“An important part of the global air motion in the mid-latitudes of the Earth normally takes the form of waves wandering around the planet, oscillating between the tropical and the Arctic regions [the jet stream, eds]. So when they swing up, these waves suck warm air from the tropics to Europe, Russia, or the US, and when they swing down, they do the same thing with cold air from the Arctic,” explains Vladimir Petoukhov.
“What we found is that during several recent extreme weather events these planetary waves almost freeze in their tracks for weeks. So instead of bringing in cool air after having brought warm air in before, the heat just stays. In fact, we observe a strong amplification of the usually weak, slowly moving component of these waves,” says Petoukhov.
The study shows time is critical to this process. Two or three days of 86-degree Fahrenheit weather are no problem, but twenty or more days lead to extreme heat stress. prolonged hot periods can result in a high death toll, forest fires, and dramatic harvest losses for the many ecosystems and cities not adapted to such temperatures.
Global warming caused by greenhouse gas emissions from burning fossil-fuels is not uniform. In the Arctic, for example, the relative temperatures, amplified by the loss of snow and ice, is higher than on average [Arctic Amplification, eds] . As a result, the temperature difference between the Arctic and, for example, Europe is reduced, yet temperature differences are a main driver of air flow. It should be noted that continents warm and cool more readily than the oceans.
“These two factors are crucial for the mechanism we detected,” says Petoukhov. “They result in an unnatural pattern of the mid-latitude air flow, so that for extended periods the slow synoptic [the larger-scale "long-waves", eds] waves get trapped.”
To describe the wave motions in the extra-tropical atmosphere and show under what conditions those waves can grind to a halt and become amplified, the team developed equations which were then tested using daily standard weather data from the US National Centers for Environmental Prediction (NCEP). The trapping and strong amplification of particular waves – like “wave seven” (which has seven troughs and crests spanning the globe) – was observed during recent periods of major weather extremes. The data collected by the researchers show an increase in the occurrence of these specific atmospheric patterns, which is statistically significant at the 90-percent confidence level.
[Jet stream flow depicted at 500 millibars, roughly 5000-6000 metres, the flow is parallel to these contours. These contours are lines of equal height, where the pressure equals 500 millibars, which is a function of temperature. The higher the heights, the warmer overall the airmass is, e.g., the 582 contour = 5820 metres. Note "long-wave" larger ridges offshore of western North America and the UK/France/Spain. "Short-wave" ridges and troughs within these larger scale features are smaller-scale disturbances which move through these "long-waves", which this research shows now are slowing and becoming more persistent. eds.]
“Our dynamical analysis helps to explain the increasing number of novel weather extremes. It complements previous research that already linked such phenomena to climate change, but did not yet identify a mechanism behind it,” says Hans Joachim Schellnhuber, director of PIK. “This is quite a breakthrough, even though things are not at all simple – the suggested physical process increases the probability of weather extremes, but additional factors certainly play a role as well, including natural variability.”
The project spans a 32-year period, which provides a good indication of the mechanism involved, yet is too short for definite conclusions.
The study significantly advances the understanding of the relation between weather extremes and man made climate change, however, surprising the scientists with how far outside past experience some of the recent extremes have been. The emergence of extraordinary weather is not just a linear response to the mean warming trend, the study shows, suggesting the proposed mechanism could explain that.
So there you have it. Researchers are now able to scientifically describe not just how the global climate system is changing due to the increased heat from higher levels of CO2 and methane in the atmosphere, but the actual mechanisms that are acting to transport and re-distribute this increasing warmth.
Meanwhile, as the following article attests,
Arctic Sea Ice is now rapidly collapsing, and we here at the APR expect to see summer ice-free conditions within 5-8 years. Which will mean even further warming in the Arctic, reducing the tropical-polar temperature gradients ever more. Leading to more (and likely stronger) scenarios such as the previous article, and ours we've presented, have described.
Scientists Confirm: Arctic Sea Ice 'Collapse' at Our Door
Warming planet and new evidence portend future of ice-free Arctic
The Arctic Sea is experiencing rapid ice loss at a pace
so fast that the area will soon be ice-free in warmer months, scientists confirmed
in a report this week—showing a collapse in total sea ice volume to one fifth of
it
Arctic sea ice volume in 1000s of cubic kilometers (via Robinson)s level in 1980.
The alarming rate of melting was measured by the European Space Agency’s
CryoSat-2 satellite, which uses new technology to measure the thickness of the
sea ice in addition to how much of the region is covered.Arctic sea ice volume in 1000s of cubic kilometers (via Robinson)s level in 1980.While ice thickness is more difficult to see with the naked eye, its decline in volume is a harbinger of faster and more alarming ice loss, the scientists urged.
"Not only is the area getting smaller, but also its
thickness is decreasing and making the ice more vulnerable to more rapid
declines in the future," Christian Haas, a geophysicist at York University in Canada,
told NBC News.
The Arctic sea already hit record lows in 2012 with the lowest amount of ice
on record, covering only half the average area covered between 1979 and
2012.The newly released data confirms earlier reports—which included data from NASA's ICESat satellite between 2003 to 2008—that the Arctic, which normally maintains vast amounts of ice throughout the year, may soon be ice-free during warmer months. Another team of scientists came to the same conclusion in September using the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the University of Washington’s Polar Science Center.
"As the satellite measurements show that not only the area decreases but also its thickness, it is actually becoming more likely that the ice will disappear sooner rather than later," Haas told NBC News.
Researchers published the study online in Geophysical Research Letters.
"Other people had argued that 75 to 80 percent ice volume loss was too
aggressive," said co-author Axel Schweiger in a press release. "What this
new paper shows is that our ice loss estimates may have been too conservative,
and that the recent decline is possibly more rapid."
The Natural Environment Research Council (NERC), commented on the new
findings in a press release:Arctic sea ice volume has declined by 36 per cent in the autumn and 9 per cent in the winter between 2003 and 2012, a UK-led team of scientists has discovered….
The findings confirm the continuing decline in Arctic sea-ice volume simulated by the Pan-Arctic Ice-Ocean Modelling & Assimilation System (PIOMAS), which estimates the volume of Arctic sea ice and had been checked using earlier submarine, mooring, and satellite observations until 2008.
The data gathered so far by Cryosat were compared with information compiled by the US space agency's (Nasa) Icesat spacecraft in the mid-2000s.
For autumn (October/November), the analysis found the Icesat years from 2003 to 2008 to have recorded an average volume of 11,900 cubic km.
But from 2010 to 2012, this average had dropped to 7,600 cu km - a decline of 4,300 cu km - as observed by Cryosat.
For winter (February/March), the 2003 to 2008 period saw an average of 16,300 cu km, dropping to 14,800 cu km between 2010 and 2012 - a difference of 1,500 cu km.
The smaller relative decline in winter volume highlights an interesting "negative feedback".
New record low Arctic sea ice extent, reached in September 2012,
compared to the average summer minimum extent for the last 30 years in yellow.
Source: NASA 
Monthly sea ice volume anomalies from 1979 to the present (Axel
Schweiger / UW)
Of additional great concern, described in the article below,
is the fact that as the Arctic continues to warm, permafrost melting will release vast amounts of methane and CO2 that are currently locked up in the frozen subsurface layers. Which will be a "positive feedback" mechanism in the coming decades, producing even greater warming. And very likely, much greater melting of glacial ice in Greenland and Antarctica, producing rapid sea level rises.
This future scenario, which would eventually lead to great chaos and possibly the collapse of what we like to think of as "civilisation", as seaports are drowned, and the global transport of food/energy/industrial outputs ends, does not have to occur.
As the links below describe, alternative energy research and developments in being able to remove CO2 from the atmosphere are occurring.
What is needed is a crash-program to massively fund and develop on a global scale systems like these. Which would take just a fraction of what the US spends on it's "defense" budget yearly. The choice is ours.
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