# 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.)

r

Previous entries:

Barriers in the Atmosphere
Behavior
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.”

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##### 857. goosegirl1
 Quoting 852. Doxienan:We installed a heat pump water heater. Initially, we wanted to install a solar hot water system, but the solar installer explained that the cost of solar PV is so low that solar thermal doesn't make sense. We added another 2KW of solar panels to provide hot water. There is more than enough for the two of us and lots of company on weekends. And I think we got a rebate from the electric company for it.Our house is south-facing and unobstructed. We live in New Hampshire at a high elevation. Lots of sun, but lots of winter. The PV system supples more than enough for our household electric, the water heater, and our plug-in car. We also added a lot of insulation (spray-on and rigid foam) and new windows. So far, an efficient woodstove is all we need to heat the house, with the original oil furnace as backup if we ever have to go away. If you're building a new house, I would investigate the German 'passive house'. Although our house is more than 200 years old, with careful planning, we have insulated it to withstand even the coldest NH winters.I like the passive house concept. I didn't know it at the time, but we incorporated a few of the design elements. The HVAC is a high efficiency reversable heat pump, with a 95% efficient propane furnace as back-up when the temps are too cold for the heat pump. The house is heavily insulated and well sealed. I'm hoping the heat pump water heater saves a lot of energy, along with energy star appliances. It only makes sense to us- it's responsible, and it saves money. We are also adding solar outside lighting.
##### 856. JohnLonergan
 From Bart Verheggen at My View on Climate Change:BBC interview: global warming pause, climate sceptics, long timescalesI was interviewed by Matt McGrath from the BBC last week, as were several other Dutch climate spokespeople (including PBL’s senior scientist Arthur Petersen and skeptical science writer/journalist Marcel Crok). Short parts of these interviews have appeared on the web and on Radio 4 (“The World Tonight”, 26-09). Below I try to provide a bit of context to my quotes.Both pieces are centred, as is fashionable these days, on the apparent smaller rate of surface warming in the past 15 years. The web piece is entitled “Climate sceptics claim warming pause backs their view”. Of course they claim it does. What sceptics did achieve –credit where credit is due- is to put this so-called “pause” on the agenda of mainstream media, until it got so fashionable that they all feel forced to use it as an anchor for any reporting on climate. But, as Gavin Schmidt is quoted as saying:focus on a global warming pause over the past 15 years is a “misplaced” distraction that misses the big picture. He said, “The IPCC and the issue of climate change is not about the weather next year or the next five years; it’s about the long-term climate change that we are engendering.”See also this useful figure from Stefan Rahmstorf, underscoring the silliness of drawing all too strong conclusions from 15-year trends.Figure showing NASA GISS global average temperatures with trendlines from 1992-2006 (light blue) and 1998-2012 (green) as well as the most recent 30-year trend in red. Naturally, starting in a very cold volcano-influenced or very warm El Nino influenced year will inflate or deflate the trend. (source: Stefan Rahmstorf)Read more >>
Member Since: June 27, 2012 Posts: 0 Comments: 4222
##### 853. JohnLonergan
 Colorado Floods - statistical certainty vs geophysical realitiesColorado experienced its most extreme weather event in memory between September 9th to the 15th. Golden, Boulder and Larimer counties received the worst of it with rain accumulations of sixteen/seventeen inches and more, some areas receiving nine inches on Thursday alone, resulting in massive flooding compounded by destructive run-off from mountainsides of burned-out forests that could no longer hold water.Predictably folks are asking: Is this related to manmade Global Warming? It's an easy and tough question to answer.Consider please, our climate system is a global heat distribution engine and our land, atmosphere, and the oceans have indisputably warmed, not only that, our atmosphere's moisture content has been measurably increasing. Given such geophysical realities, it is self-evident that all extreme weather events contain elements of this newly energized climate system. And that much more of the same must be expected.Read More ...
Member Since: June 27, 2012 Posts: 0 Comments: 4222
##### 852. Doxienan
 Quoting 831. goosegirl1:Time for a serious question and a shameless diversion from the, well, oddity to use a polite term. Has anyone installed a heat pump water heater in their home? I am considering it but wondered if there were any savings realized. I don't mind putting down the cash if it really heats water and does it effciently, but it is \$900 more than a standard electric. Thoughts?We installed a heat pump water heater. Initially, we wanted to install a solar hot water system, but the solar installer explained that the cost of solar PV is so low that solar thermal doesn't make sense. We added another 2KW of solar panels to provide hot water. There is more than enough for the two of us and lots of company on weekends. And I think we got a rebate from the electric company for it.Our house is south-facing and unobstructed. We live in New Hampshire at a high elevation. Lots of sun, but lots of winter. The PV system supples more than enough for our household electric, the water heater, and our plug-in car. We also added a lot of insulation (spray-on and rigid foam) and new windows. So far, an efficient woodstove is all we need to heat the house, with the original oil furnace as backup if we ever have to go away. If you're building a new house, I would investigate the German 'passive house'. Although our house is more than 200 years old, with careful planning, we have insulated it to withstand even the coldest NH winters.
##### 851. VR46L
 Umm I am pretty sure that is a serious breach of site rules .... posting what purports to be a private message ... I would suggest you take that down as I am pretty sure thats a perma ban offence
##### 849. JohnLonergan
 A new European report on climate extremes is out.A new report on extreme climate events in Europe is just published: ‘Extreme Weather Events in Europe: preparing for climate change adaptation‘. It was launched in Oslo on October 24th by the Norwegian Academy of Science and Letters, and the report is now available online.What’s new? The new report provides information that is more specific to Europe than the SREX report from the Intergovernmental Panel on Climate Change (IPCC), and incorporate phenomena that have not been widely covered.It provides some compelling information drawn from the insurance industry, and indeed, a representative from Muncih Re participated in writing this report. There is also material on convective storms, hail, lightening, and cold snaps, and the report provides a background on extreme value statistics, risk analysis, impacts, and adaptation.The main difference with the recent IPCC reports (e.g. the SREX) is the European focus and that it includes more recent results. The report writing process did not have to follow as rigid procedures as the IPCC, and hence the report is less constrained. For instance, it provides set of recommendations for policymakers, based entirely on scientific considerations.The report, in which I have been involved, was initiated by the Norwegian Academy of Science and Letters, and was written by a committee of experts across Europe. Hence, the final report was published as a joint report by the Norwegian meteorological institute, the Norwegian Academy of Science and Letters, and the European Academies Science Advisory Council (EASAC)
Member Since: June 27, 2012 Posts: 0 Comments: 4222
 Re:844The Mark Twain quote kinda supports my position.
Member Since: July 25, 2006 Posts: 2 Comments: 788
##### 847. JohnLonergan
 Quoting 835. BaltimoreBrian:I see how you got me in there.Napolean posting as Lonegan63
Member Since: June 27, 2012 Posts: 0 Comments: 4222
##### 846. bappit
 Quoting 845. Xulonn:Aquinas was spot on with sin as voluntary ignorance "as when a man wishes of set purpose to be ignorant of certain things that he may sin the more freely."
##### 845. Xulonn
 Sinners - repent. For AGW/CC denialism violates the 8th Commandment - "Bearing false witness."Quoting David Cruz-Uribe, SFO, at Vox Nova:We can now turn to my original question: is climate change denial a sin? I believe that it is. More specifically, it is a sin against the eighth commandment: you shall not bear false witness. In a word, it is lying. The Catechism defines lying as follows: “To lie is to speak or act against the truth in order to lead into error someone who has the right to know the truth” (2483). If the theory of climate change is true - and the overwhelming consensus of those qualified to hold an opinion is that it is — then denying it or calling it a hoax is to “speak against the truth.” And given the gravity and universality of the impact that climate change will have in the future, every person has a right to know the truth about it.One could argue that while those who deny the reality of climate change are in error, they are not deliberately lying since they are ignorant of the truth and express their beliefs sincerely. This is possible, but it strains my credulity to believe it. Further, it raises the question of whether this ignorance is involuntary or willful. Thomas Aquinas explained the difference in this way:It is clear that not every kind of ignorance is the cause of a sin, but that alone which removes the knowledge which would prevent the sinful act. …This may happen on the part of the ignorance itself, because, to wit, this ignorance is voluntary, either directly, as when a man wishes of set purpose to be ignorant of certain things that he may sin the more freely; or indirectly, as when a man, through stress of work or other occupations, neglects to acquire the knowledge which would restrain him from sin. For such like negligence renders the ignorance itself voluntary and sinful, provided it be about matters one is *bound and able to know.”
Member Since: June 11, 2012 Posts: 0 Comments: 1725
##### 844. Xulonn
 Quoting 799. PensacolaDoug:Are you incapable of comprehending something you read?That's not what happened at all. If you follow the series of posts, it appears that Nea responds, but under the JL moniker. (Edited for clarity.)Appearances can be deceiving...
Member Since: June 11, 2012 Posts: 0 Comments: 1725
##### 842. goosegirl1
 Quoting 835. BaltimoreBrian:Thanks, BB. I spotted a heat pump water heater in Lowe's and was just curious how it would perform in a basement and supplying 3 people. I didn't know exactly how they worked until I read on your link- a reverse refrigerator, cool (or warm, if you like- bad pun!)We are just beginning to build a new home and any suggestions on high efficiency and energy saving would be welcome. We do not have access to natural gas so we have to rely on a heat pump to heat and cool, with a propane backup since we get brutal winters here. Any ideas?
##### 841. schwankmoe
 Quoting 839. GiovanniDatoli:I hope so. I really do hope so.dogg i've been calling that dude out over 'it's the sun!' for a while now. you're new to the forum, you might want to read back a bit or at least watch the back-and-forth a bit before deciding who's who and what's what. it'll help a lot.
Member Since: October 18, 2005 Posts: 0 Comments: 819
##### 840. schwankmoe
 Quoting 829. HardTimesHenry:An man of integrity that can apologize. i'm a man of integrity? gee, thanks, mister!
Member Since: October 18, 2005 Posts: 0 Comments: 819
##### 838. schwankmoe
 Quoting 836. GiovanniDatoli:Incorrect on all counts.Can we try to stay away from infamous Roy Spencer garbage playbook and get back to what we try to call, um, you know, science...SighRoy Spencer has done some good work in the past with satellite sensing. However, as noted previously, he has over recent years stepped far outside the mainstream of science (climate and otherwise), latching onto one debunked, disproved, and discredited bit of anti-science after another. While that's made him a darling of the fossil fuel crowd, it has caused him a large drop in credibility and respectability in the science community--and rightly so. In addition (and for example), he's come out in support of the decidedly non-science of creationism, claiming (in contradiction to every biologist alive) that it's every bit as real as evolution.Seriously.To summarize, then: Spencer = good with satellite temperature data, bad with most everything else.I was kidding.
Member Since: October 18, 2005 Posts: 0 Comments: 819
##### 835. BaltimoreBrian
 Quoting 834. schwankmoe:it's gotta be the sun.
##### 834. schwankmoe
 Quoting 826. iceagecoming:There are a bunch here with low heat tolerance.When the facts don't match the theory, testy.it's gotta be the sun.
Member Since: October 18, 2005 Posts: 0 Comments: 819
##### 833. RevElvis
 We’ve Reached “The End of Antibiotics, Period”Bacteria, like any living organism, want to survive. They are adapted that way, and any successful bacteria is the bacteria that’s most able to survive in the environment. So bacterial resistance is largely inevitable, because bacteria will always change in order to survive.So anything that we do to try and kill bacteria, or anything the environment does to try and kill bacteria, bacteria will eventually discover ways or find ways around those.It’s important to know that this is a phenomenon that plays out in nature. Most of the antibiotics that we have available to us now were derived from products in nature. So penicillin was an agent that was excreted by molds in order to kill bacteria. Eventually bacteria will evolve, and they’ll adapt ways around that to overcome that obstacle.There are lots of bacteria. They have the advantage on us in terms of numbers. And whenever you have that many of an organism, it’s likely that one among them will be resistant to an antibiotic.If you use an antibiotic, then that one among the group that is resistant becomes the predominant one. So resistance is something that is an inevitable consequence of bacterial evolution. But it’s also something that we have certainly helped along the way.pbs.org (Frontline)
##### 832. BaltimoreBrian
 Quoting 831. goosegirl1:Time for a serious question and a shameless diversion from the, well, oddity to use a polite term. Has anyone installed a heat pump water heater in their home? I am considering it but wondered if there were any savings realized. I don't mind putting down the cash if it really heats water and does it effciently, but it is \$900 more than a standard electric. Thoughts?This might help
##### 831. goosegirl1
 Time for a serious question and a shameless diversion from the, well, oddity to use a polite term. Has anyone installed a heat pump water heater in their home? I am considering it but wondered if there were any savings realized. I don't mind putting down the cash if it really heats water and does it effciently, but it is \$900 more than a standard electric. Thoughts?
##### 828. barbamz
 Critical article about Germany's efforts of the so called "Energiewende" (maybe some truth in it):Reality Check: Germany's Defective Green Energy Game PlanA Commentary By Alexander NeubacherSpiegel English, Oct. 25, 2013Germany pretends to be a pioneer in the green revolution. But its massively expensive Energiewende has done nothing to make the environment cleaner or encourage genuine efficiency. One writer argues: Either do it right, or don't do it at all.
##### 826. iceagecoming
 Quoting 797. ncstorm:LOL..you guys are cracking me up with these possible scenarios..LOL..so now you speak for Skyepony..Donnie said in his previous post that "Skyepony is a mod and would know"..well she has laid it out for me in the main blog as well as on admin's blog that she dont have access to IP address nor does any other mod until admin gives it to them..she will need to come in here and verify how she got an IP address so easily when she in fact told me that wasnt possible..did she look up Nea's real name on that handle to see if he would foolishly apply to another handle..right..and dont try to turn it around on me like I'm worried..sorry to crush your dreams but no second handles over here..I'm just showing the holes in this so called web of deceit on rood's blog..LOLThere are a bunch here with low heat tolerance.When the facts don't match the theory, testy.
##### 824. iceagecoming
 Quoting 609. Xulonn:Iceagecoming demonstrates by his comments that her/she despises Dr. Masters and thinks the "good doctor," as many denialists call him at his blog, is an idiot!You can keep your theories and hate speech to yourself. Trying to point out the inconsistencies that many try to (overlook, fudge) is telling. Empirical data XULU? Not working for you.
 Quoting 820. schwankmoe:I think somebody mentioned that earlier.Apology accepted. I wouldn't do that. That's not how I roll.
Member Since: July 25, 2006 Posts: 2 Comments: 788
##### 820. schwankmoe
 Quoting 819. PensacolaDoug:Why did u think that?I think somebody mentioned that earlier.
Member Since: October 18, 2005 Posts: 0 Comments: 819
 Quoting 817. schwankmoe:I thought you posted all this stuff to the admin's blog. I guess I was wrong, sorry about that.Why did u think that?
Member Since: July 25, 2006 Posts: 2 Comments: 788
Member Since: July 25, 2006 Posts: 2 Comments: 788
##### 817. schwankmoe
 Quoting 815. PensacolaDoug:Since when did I ever call for a ban?I thought you posted all this stuff to the admin's blog. I guess I was wrong, sorry about that.
Member Since: October 18, 2005 Posts: 0 Comments: 819
##### 816. schwankmoe
 Quoting 814. PensacolaDoug:And as for who really gives a crap outside of you?It wouldn't matter to you as long as he spouts all the right talking points no matter how many sp's he may have.I don't give a crap about anybody's alleged sockpuppetry. it just doesn't matter very much. it's a silly thing to obsess over, much less with such little evidence.
Member Since: October 18, 2005 Posts: 0 Comments: 819
 And as for who really gives a crap outside of you?It wouldn't matter to you as long as he spouts all the right talking points no matter how many sp's he may have. Keeping in mind I only alleged one.
Member Since: July 25, 2006 Posts: 2 Comments: 788
##### 812. Patrap
Member Since: July 3, 2005 Posts: 433 Comments: 132748
##### 810. JohnLonergan
Member Since: June 27, 2012 Posts: 0 Comments: 4222
##### 808. RevElvis
 Oil companies in North Dakota fail to report almost 300 oil spills since 2012The director of the North Dakota Department of Mineral Resources, Lynn Helms, told the Associated Press that companies are worried about “over-reporting” spills. The state is trying to strike a balance so that “the public is aware of what’s happening, but not overwhelmed by little incidents.”One wheat farmer told the AP that he’s in favor of receiving information about every incident, since his livelihood depends on his land. He’s worried because the policy at the moment is “[w]hat you don’t know, nobody’s going to tell you.”“It would tell me if there is enough oversight and why these accidents happen and if they could have been avoided,” he said. “Right now, you don’t know if there is a spill unless you find it yourself.”RawStory.com
##### 807. Patrap
 Kate Sheppardkate.sheppard@huffingtonpost.comClimate Scientist Campaigns Against Ken Cuccinelli In Virginia Governor's RacePosted: 10/17/2013 11:45 am EDT | Updated: 10/17/2013 2:57 pm EDTWASHINGTON -- Climate scientist Michael Mann has teamed up with NextGen Climate Action in a new web video posted last week, urging Virginians to vote against Republican Ken Cuccinelli in the governor's race.Mann, a former University of Virginia professor, has been the subject of Cuccinelli's anti-climate science attacks. Beginning in April 2010, Cuccinelli attempted to use his position as the state attorney general to subpoena Mann's records and email correspondence, in order prove that the scientist's research constituted "fraud" against taxpayers in the state. The effort dragged on for two years and cost UVA hundreds of thousands of dollars, but was ultimately unsuccessful.Mann, who is now the director of the Earth System Science Center at Pennsylvania State University, campaigned against Cuccinelli in the state in July. Now he's taking to the web, accusing the attorney general of "trying to attack the science of climate change by attacking me." Mann's entry into the Virginia campaign marks an unusual step for a climate scientist."One would like to think that the attorney general would be representing the people of his state. Unfortunately, Ken Cuccinelli chose to spend the taxpayers' money, forced the University of Virginia to spend \$600,000 defending itself, and untold millions of dollars mounting this attack," Mann says in the video, posted last Tuesday. "Those millions of dollars could have been used to help Virginians already start to cope with the impacts that we're already seeing of climate change.""Climate change is here. We have to do something about it now," Mann says. "There's nothing you can do that's more important than voting and encouraging your friends and family and everyone else you know to vote."
Member Since: July 3, 2005 Posts: 433 Comments: 132748

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