Wobbles in the Barriers: Arctic Oscillation (4)

By: Dr. Ricky Rood , 4:22 PM GMT on October 14, 2013

Wobbles in the Barriers: Arctic Oscillation (4)

This is a continuation of my series on the Arctic Oscillation / North Atlantic Oscillation. Links to background material and previous entries are at the end.

In the last entry I suggested that if you were on a bridge overlooking a swiftly flowing creek then you would notice that twigs floating in the water did not move across the current. They are carried downstream along the edge of the current. The purpose of that comparison was to demonstrate how fast-moving, concentrated flows have the effect of isolating one side of the creek from the other. This is true in the creek, and it is also true about jet streams in the atmosphere.

One way to understand the Arctic Oscillation is to think of it as the variation of an atmospheric jet stream. For the Arctic Oscillation the jet stream of interest is the southern edge of vortex of air that circulates around the North Pole (see previous entry). Air inside the vortex often has characteristics different from air outside it. Intuitively for the Arctic, there is colder air on the side toward the pole. If you look at trace gases, like ozone, they are different across the edge of the vortex. The takeaway idea is that the edge of the vortex is a barrier. It’s not a perfect barrier, but the air on one side is largely separated from the air on the other side. In this blog, I describe the difference between a strong and a weak vortex – which is the same as the difference between the positive and negative phases of the Arctic Oscillation and the North Atlantic Oscillation.

Figure 1: This figure is from the point of view of someone looking down from above at the North Pole (NP). Compare this perspective to Figure 1 in previous blog. This represents a strong, circular vortex centered over the pole, which encloses cold air, represented as blue. The line surrounding the cold air is the jet stream or the edge of the vortex.

Figure 1 shows an idealized schematic of the North Pole as viewed from above. This is the strong vortex case, when there is exceptionally low pressure at the pole. Low pressure is associated with counterclockwise rotation in the Northern Hemisphere. This direction of rotation is called cyclonic. This strong vortex case is the positive phase of the Arctic Oscillation. During this phase, the vortex aligns strongly with the rotation of the Earth, and there are relatively few wobbles of the edge of the vortex – the jet stream. I drew on the figure two points, X and Y. In this case, the point X is hot and the point Y is cold. It is during this phase when it is relatively warm and moist over, for example, the eastern seaboard of the United States.

Figure 2 compares a strong vortex and a weak vortex. In both cases, the circulation around a central point is counterclockwise or cyclonic. However, in the weak vortex case, the vortex does not align as strongly with the rotation of the Earth and there are places where the edge of vortex extends southwards. The vortex appears displaced from the pole; it is not centered over the pole.

Figure 2: Examples of a strong, circular vortex and a weak, more wavy vortex. See text for a more complete description.

Whether the vortex is stronger or weaker is determined by the atmospheric pressure at the pole. In the winter, an important factor that determines the circulation is the cooling that occurs at polar latitudes during the polar night.

What determines the waviness or wobbles at the edge of this vortex? The structure at the edge of vortex is strongly influenced by several factors. These factors include the structure of the high-pressure centers that are over the oceans and continents to the south of jet stream. One could easily imagine a strong high-pressure center over, for example, Iceland, pushing northward at the edge of the vortex. This might push a lobe of air characteristic of the middle latitude Atlantic Ocean northward. Since the edge of the vortex is something of a barrier, this high-pressure system would distort the edge of the vortex and, perhaps, push the vortex off the pole. This would appear as a displacement of the vortex and its cold air over, for example, Russia. If the high grew and faded, then this would appear as wobbles of the vortex.

Other factors that influence the waviness at the edge of the vortex are the mountain ranges and the thermal contrast between the continents and the oceans. The impact of mountains is easy to understand. Returning to the creek comparison used above, the mountains are like a boulder in the stream. The water bulges around and over the boulder; the air in the atmosphere bulges around and over the mountain ranges. The Rocky Mountains in the western half of North America are perfect examples of where there are often wobbles in the atmospheric jet stream.

Figure 3: This figure is from the point of view of someone looking down from above at the North Pole (NP). This represents a weak, wavy, wobbly vortex displaced from the pole. The vortex encloses cold air, represented as blue. The line surrounding the cold air is the jet stream or the edge of the vortex. (definition of vortex)

Figure 3 shows an idealized schematic of the North Pole as viewed from above. This is the weak vortex case, when the low pressure at the pole is not as low as average and the pressure is much higher than the strong vortex case of Figure 1. This weak vortex case is the negative phase of the Arctic Oscillation. During this phase, the alignment of the vortex with the rotation of the Earth is less prominent, and there are wobbles of the edge of the vortex – the jet stream. In this case, the point X is cold and the point Y is hot. It is during this phase where it is relatively cool and dry (but potentially snowy) over, for example, the eastern part of the United States.

These figures help to explain the prominent signal of the Arctic Oscillation discussed in the earlier entries (specifically, this blog). That is, when the vortex is weak and wobbly, then there are excursions of colder air to the south and warmer air to the north. This appears as waviness and is an important pattern of variability - warm, cold, warm, cold.

The impact of the changes in the structure of edge of the vortex does not end with these persistent periods of regional warm and cold spells. The edge of the vortex or the jet stream is also important for steering storms. Minimally, therefore, these changes in the edge of the vortex are expected to change the characteristics of how storms move. Simply, if the edge of the vortex has large northward and southward extensions, then storms take a longer time to move, for example, across the United States from the Pacific to the Atlantic Oceans. In the positive phase of the Arctic Oscillation they just whip across. In the negative phase, the storms wander around a bit. A more complete discussion of this aspect of the role of the Arctic Oscillation will be in the next entry. (Note use of dramatic tension and the cliffhanger strategy of the serial.)


Previous entries:

Barriers in the Atmosphere
Definitions and Some Background

August Arctic Oscillation presentation

CPC Climate Glossary “The Arctic Oscillation is a pattern in which atmospheric pressure at polar and middle latitudes fluctuates between negative and positive phases.”

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

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There is no pause yoboi and I and others have posted official measurements refuting your claim on several occasions.

Here is the GISS report.

NASA Research Finds 2010 Tied for Warmest Year on Record

2010 and 2005 are the warmest years on record. 1998 is third. From now on if you post there has been a pause we know you are lying.
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Quoting 199. Birthmark:

If there's no pause then there is no cause.

That's the actual case, btw. I've posted several graphs of temperature data that clearly demonstrate that it has been warming. The fact that you answer the data with nothing more than denial might lead one to conclude that you are a...now what's that word? lol

If evidence doesn't mean anything to you, why are you here?

Birthmark, What would you call asking the same question repeatedly and expecting a different answer? I know what Einstein called it.
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The Wealthy Will Lose Money Betting Against Global Warming

There is a lot of discussion about how victims of poverty will get hit the hardest from climate change disasters, but how will radical climate changes impact world economies, and the wealthiest members of society?

The consequences have proven that the poor suffer dramatically more from climate change disasters than the rich, but prosperous businesses are also being severely challenged and impacted. No industry falls alone. In the financial markets, everything is interconnected. Climate change is having a crippling ripple effect across global economies.

Wealthy investors will be hit hard by global warming. It's inevitable that billion dollar businesses will, if they haven't already, encounter vast losses of income given the range of investments affected by climate impacts in agriculture, fishing industries, tourism, real estate, insurance, and much more.

Global warming does not discriminate between the rich and those who are struggling to make ends meet. Global warming doesn't take bribes for favors or protection. Global warming trumps politics. There is nothing liberal or conservative about rising sea levels, floods and cruel droughts.


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From Media Matters for America:

Weather Channel Founder: Polar Bears Have Increased Because "Eskimos" Are Now "More Civilized"

San Diego TV Station Airs Heartland Institute Climate Denial Infomercial

The founder of the Weather Channel, now a local weatherman on a San Diego television station, dedicated nearly half an hour to climate change misinformation, including claiming that there are more polar bears because "Eskimos ... have now become more civilized."

John Coleman, who is a weatherman for the independent news station KUSI News after being "forced" out of the Weather Channel, said in a segment on climate change this week that polar bear populations have increased because "the Eskimos no longer kill the polar bears for the meat and furs in order to stay alive, it's -- we have now become more civilized in our Eskimo populations around the poles."

Video: Weather Channel Founder: Polar Bears Have Increased Because "Eskimos" Are "More Civilized"

In fact, the majority of polar bear populations for which there are sufficient data are declining. Those population levels are somewhat higher than in the 1970s thanks to a ban on polar bear hunting with limited exceptions for traditional hunting by Inuit populations. However, despite conservative media claims to the contrary, this recovery in no way negates the ongoing existential threat that global warming poses to polar bear populations.

In the segment, Coleman -- who has accused NASA climate researchers of "lying" about temperature records -- hosted four paid associates of the Heartland Institute, which has received funding from the fossil fuel industry and once compared those who accept climate science to the "Unabomber." Coleman called Heartland Institute President Joseph Bast, who claimed in the 1990s that moderate smoking has "few, if any, adverse health effects" while simultaneously receiving money from tobacco giants Philip Morris, "a hero of mine."

In addition to his "hero" and Jim Lakely, a Heartland spokesman, Coleman hosted Fred Singer and Bob Carter, who have been paid by the Heartland Institute and other organizations with fossil fuel funding. Coleman labeled them "distinguished -- and I mean truly distinguished and important -- climate scientists" and "absolute experts," even though between the two of them, they have only published a single peer-reviewed article casting doubt on manmade global warming. Both have repeated popular climate myths (Singer called climate change "bunk" and Carter said "carbon dioxide emissions are an environmental benefice [sic] ... it is plant food").

Coleman is not the only media figure to promote the discredited Heartland Institute. In fact Lakely told Coleman that in an "enormous victory," the group secured coverage from The Washington Post and The New York Times for a recent report that one climate scientist said contains "demonstrable garbage and falsehoods."

Video: "Enormous Success": Heartland Institute Celebrates Media Covering Climate Denial
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Wyatt and Curry part II: not waving but drowning

Begin by reading Role for Eurasian Arctic shelf sea ice in a secularly varying hemispheric climate signal during the 20th century? That post offers some snarks on the paper, and some indications why you might distrust it, but no really substantive criticism. I%u2019ll try to do that here but I won%u2019t fully succeed because (just like Wyatt and Curry) I don%u2019t really understand MSSA. I%u2019m hoping that someone how does know it will do a proper analysis.

Where%u2019s the meat?
If you look through the paper to find the core substance, you won%u2019t. There are layers of mush and piles of words but precious little hard matter. Figure 12 is about the closest they come to a mechanism, but its just a pile of words arranged in a picture; there%u2019s no maths here. So really, we%u2019re reduced to figure 2 and similar as being the only vaguely convincing bits.

And%u2026 well, it looks good, doesn%u2019t it? All those nice smooth wave-like lines showing clear evidence of %u201Cpropagation%u201D. What more could you want? Weeellll%u2026

... I think that%u2019s about it, really. All the stuff about exploding sardines is just fluff and can be ignored. The %u201Cmechanisms%u201D is an extended exercise in self-delusion.

my italics

To sum it up, ust more of Curry's tripe.

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..she blinded him with Science!

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Quoting 176. Cochise111:

Yes seriously. No trend from approximately 2000 to the present.

As an aside, another "environmentalist" sees the light:
Ouch! Man, did you get suckered on the Jim Steele b.s. or what!!

I went to HotWhopper and read the thorough shredding of Steele's really bad understanding of science and the dynamics and interactions of scientists in the biological effects of AGW/CC. I cringed at the thought that anyone would be foolish enough to dare post such rubbish here at the WU/CC blog comments section, where a number of intelligent folks with critical thinking and analytical skills would tear it apart.

I found that I agree with most of the comments at the end of the HotWhopper debunking article - here'a a sampling.

- I have to say that the man is a master cherry-picker.

- As far as I can see, Jim Steele will pick any fact (can be quite unrelated to the topic at hand) and turn it into a rant about how all the scientists are wrong about global warming.

- I just went back and read one of them. I also read one of the papers from which he picked out the bits that suited his meme and it was very noticeable the bits he didn't pick - and in fact that he flat out contradicted.

- And he pretends to be an environmentalist. What a horrible man.

- Steele seems to be a rising belch in the denial bog.
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Quoting 176. Cochise111:

Yes seriously. No trend from approximately 2000 to the present.

As an aside, another "environmentalist" sees the light:

So sorry, but it appears Anthony Watts has fooled you yet again. The (wannabe) mighty Jim Steele--subject of the article to which you linked--has been discredited by multiple sources, including the wonderful HotWhopper, who helps us see that Steele is just another run-of-the-mill, self-aggrandizing Watts-Bot with a persecution complex and a barrelful of ideological axes to grind (along with both a demonstrated lack of geographical or climate knowledge, and an unhealthy obsession with a particular scientist who seems to have hurt his wittle feelers at some point). (Also see here for more Steele.)

Try again...
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Five Times Rose The Global Curve, Then Paused, And Beckoned

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Thanks, Birthmark.
Actually-doing-the-work-to-analyze-the-data-corre ctly saves the day again.
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Quoting 173. Cochise111:

[No warming since 1998/2006/insert_year zombie myth]

No. Not even half true.
Warming continues to follow the trend line. All time periods of climatic significance continue to show warming in all heat storages of the climate system.
You are again completely wrong on a fundamental level, something corrected before, which indicates deliberate dishonesty.

https://f8bbfe8f-a-62cb3a1a-s-sites.googlegroups. com/site/wmscottlincoln/home/other/global-temperat ure-contributors/related-info/GISSTEMP_1979_1998_t rend.jpg
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Maybe I should just ignore the long term signal and focus on the
dramatic cooling that has occurred in the past 60 days at my NH midlatitude location (Washington DC)
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Jim Steele has hardly published anything in the empirical literature. When he claims that Polar Bears have benefitted from a reduction in Arctic ice he is nominally correct, but his argument assumes that the ice will remain stable hereafter. But of course both extent and thickness continue on their ‘death spiral’, meaning that Polar Bears are in deep, deep trouble.

Thing is, deniers will dredge up any opinions from people on the academic fringe if it supports their own pre-determined views. Steele is one such guy. There are so few of them that they are technically an endangered species. The vast majority of really qualified scientists wouldn’t touch Steele’s opinions with a barge pole.
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Quoting 176. Cochise111:

Yes seriously. No trend from approximately 2000 to the present.

As an aside, another "environmentalist" sees the light:


You do understand that getting a statistically significant trend by only using 12 years is tall task. It's basic statistics, I think you need a refresher...cherry picking years that suit your agenda is dishonest and flat out lying.

This is from the World Meteorological Organization looking at temps by decade. Notice something?

Your nonsense is very easy to debunk. It may play well on the conspiracy blogs, but not here.
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Quoting 173. Cochise111:

It's amazing how warmists can even distort graphs. Here's a graph taken from the same site that shows no trend since before 2000:


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An interesting read from 0urfiniteworld:

Two Views of our Current Economic and Energy Crisis

Quoting the final paragraphs:

We can think that the growth of human systems, including the economy, will go on forever, but we are almost certainly kidding ourselves. At some point, when Nature decides, new species will dominate–perhaps plants that can use more CO2. The transition will be the transition Nature dictates.

We are kidding ourselves if we think that we can decide to slowly reduce oil and fossil fuel usage over the next 40 or more years. If oil prices drop to, say, $30 barrel because of debt defaults, oil production will drop very quickly–not based on some slow decline curve. Natural gas and coal prices will drop dramatically too, essentially putting an end to their production. Jobs will disappear with the lack of fossil fuels. Eighty or ninety percent of us will again need to work in manual food production without fossil fuels. Education, government, and services of all kinds will shrink rapidly.

Nature is deciding for us right now what is ahead. We likely will have little choice in the matter. If we do have a choice at all, it is likely to be in the direction of serious back-pedaling, in terms of population, and in terms of learning to live essentially without fossil fuels. The future is likely to be very different from the past.
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Lloyd’s of London Latest Insurer to Warn on Warming, Mocks Deniers

I’ve made the point often. If you want to know if climate change is real, check with the people who actually have money on the table, skin in the game – the big insurance companies. These folks have more money than God, (almost as much as Exxon) and hire the smartest number crunchers in the world to assess their risk exposure. They are factoring in climate change, and pricing their coverage accordingly . As Eli Lehrer points out below, if they don’t get it right, someone will come in, undercut them, and eat their lunch.

Munich Re, the big euro re-insurer, has had climate on the radar since the early 1970s.

More at Climate Denial Crock of the Week...
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A climate skeptic states his case
It's an odd mix of hard-core physics, basic errors, and digs at Al Gore.

The Institute for Advanced Study, which has played host to such luminaries as Albert Einstein and Kurt Gödel, is holding a series of talks to celebrate the birthday of another one of its famous faculty: Freeman Dyson. Dyson made important contributions to a huge variety of fields and gave us the concept of the Dyson Sphere. The talks in his honor covered many of the fields that Dyson influenced. Here, we'll describe the talk by physicist William Happer.

As a physicist, William Happer is best known for laying the groundwork for adaptive optics, the method of reading the atmosphere's distortions so that telescopes can correct for them. This approach has revolutionized ground-based astronomy, allowing some observatories to produce images that rival those taken from space. These days, his research focuses on the quantum states of atoms and electrons.

Most people know of Happer for entirely different reasons. He's on the board of the George C. Marshall Institute, a conservative think tank that has attacked mainstream climate science (another member of the board is Roy Spencer, who takes a similar stance). Rather than critiquing the field in the scientific literature, Happer has generally focused on writing op-eds in The Wall Street Journal. Given that he was slated to speak to an audience of scientists at a science-focused event, I was curious to see what sort of talk he would give.

In many ways, Happer gave three different talks. And his strange mix of approaches left me wondering if any of the three should be taken seriously.

Read more at arstechnica >>
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Confused about the new IPCC's carbon budget?
So am I.

When the IPCC's new report on the physical basis of climate change was released in late September, media attention focused on a conclusion from the Summary for Policymakers that the world had emitted just over half of the allowable emissions if global warming is to be kept to 2 degrees Celsius (2°C) of warming.

Unfortunately, because many people think if you have a budget you should spend every last dollar, the "carbon budget" message could be interpreted as saying there is plenty of budget left to spend. The respected climate researcher Ken Caldeira told Climate Progress that the carbon budget concept is dangerous for two reasons:

There are no such things as an “allowable carbon dioxide (CO2) emissions.” There are only “damaging CO2 emissions” or “dangerous CO2 emissions.” Every CO2 emission causes additional damage and creates additional risk. Causing additional damage and creating additional risk with our CO2 emissions should not be allowed.
If you look at how our politicians operate, if you tell them you have a budget of XYZ, they will spend XYZ. Politicians will reason: “If we’re not over budget, what’s to stop us to spending? Let the guys down the road deal with it when the budget has been exceeded.” The CO2 emissions budget framing is a recipe for delaying concrete action now.

And the idea that 2°C of warming is safe is not a sustainable proposition. Prof. Kevin Anderson says that "the impacts associated with 2°C have been revised upwards, sufficiently so that 2°C now more appropriately represents the threshold between ‘dangerous’ and ‘extremely dangerous’ climate change".

Read more at ClimateCodeRed >>

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From Climate Crocks:

The Weather Channel’s New Series on Climate: Tipping Points

October 16, 2013

Hot tip from Jeff Masters – New Weather Channel series starts Saturday, October 19.

The Weather Channel:

Hosted by Climate Journalist and adventurer Bernice Notenboom, Tipping Points embraces commentary from leading climate scientists surveying the complexity of the major tipping points effecting our current climate and their impact on changing weather patterns around the globe.

Adventurous and informative, Tipping Points explores the interconnectedness of all the elements that make up our climate system that influence global and local weather patterns. The Earth is in a delicate equilibrium; once one factor reaches its respective tipping point the other factors will also breach stability. As the atmosphere heats up and the chemical makeup of the atmosphere shifts there will be repercussions felt on a global scale. These elements are what Bernice and her team of climate authorities are going to explore is some of the most remote locations on the planet.

From the canopies of The Amazon to the ice sheets of Siberia, these climate specialists will chase answers to behavioral patterns of tipping elements in the climate system affecting our weather systems.

How close to tipping are we? When will these climates tip and what will be the indicators? How will our climate and weather patterns be affected once stability has been ruptured? Will large-scale discontinuities be the biggest cause for climate catastrophes in this century? These are the questions Tipping Points dares to ask, and further answer.
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few statistical notes on the "hiatus"

30 years is the accepted norm for climate discussion. If you cherrypick short time frames you will find that the “pause” is not statistically significant. For any of the instrumental series, over any time span ending in the present:

• There is no period where warming is invalidated, against a null hypothesis of no warming. None.

• Against a null hypothesis of the long term warming trend, there is no period where a “no warming” hypothesis is validated. None.

• Over any period with enough data to show statistical significance, that data shows a statistically significant warming trend. Always.

Deniers conveniently forget to mentioon the 15-year time span, 1992 through 2006, during which the rate of warming was 0.28 deg.C/decade. That’s a lot faster than the warming rate from 1975 to now. The time-scales were too short for alarm then. They’re too short for complacency now.
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William Connolley(Stoat) takes a look at Curry's latest,
Role for Eurasian Arctic shelf sea ice in a secularly varying hemispheric climate signal during the 20th century?, needless to say, he's not impressed.

This is Curry’s Stadium Wave (Marcia Glaze Wyatt, Judith A. Curry, Clim. Dyn., Sept. 2013; henceforth W+C), but you don’t get a title like that past a staid journal like Climate Dynamics.

Note: the copy of W+C I started writing this from which I found at Curry’s site offers graphics of truely outstanding industrial-strength awfulness. Really: if you don’t believe me, go look. Most of them are completely unreadable (you need to go about half way down the comments at Curry’s before you find anyone who notices this, strongly suggesting what the comments there also suggest: that few have troubled themselves with reading the paper). I subsequently found a better version elsewhere, so I can’t claim ignorance as I was planning to.

Note: what this most reminds me of, off the bat, is the “Antarctic Circumpolar Wave” (White and Peterson 1996. I even made a small contribution to the literature). Its not the same – the ACW has a clearish mechanism and dynamics, and a very different though still “slow” period. But if I were W+C I’d definitely have mentioned it. Odd that they don’t.

More >>
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Quoting 128. Naga5000:

The American Thinker is not so much a thinker...you're letting political belief affect how you view science.

The only dissenting voice in climate change science comes from the extreme right in the form of blogs do you think that's a coincidence?

The America Thinker is an oxymoron.
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Dr. Ricky Rood's Climate Change Blog

About RickyRood

I'm a professor at U Michigan and lead a course on climate change problem solving. These articles often come from and contribute to the course.

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