# Dr. Ricky Rood's Climate Change Blog

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Barriers in the Atmosphere: Arctic Oscillation (3)
 By: Dr. Ricky Rood, 12:50 AM GMT on October 03, 2013 +19
Barriers in the Atmosphere: Arctic Oscillation (3)

I want to continue with the Arctic Oscillation / North Atlantic Oscillation. First, however, here is the link to my August presentation. Also here is a link to the GLISAclimate.org project workspace where I collected together the materials I used in the presentation - Arctic Oscillation: Climate variability in the Great Lakes.

Here are the previous entries in the series:
Behavior
Definitions and Some Background

This blog is mostly a setup for the next one. (And yes I did notice that the IPCC AR-5 report was released, but I don’t have anything different to say about it than many of my more able colleagues. I’ll get to it.)

In the talk that I linked to above, I used a couple of diagrams that the audience told me worked very well. I am going to try them out in this blog. In the previous blogs I used the CPC Climate Glossary to give the definition of the Arctic Oscillation. “The Arctic Oscillation is a pattern in which atmospheric pressure at polar and middle latitudes fluctuates between negative and positive phases.” This definition does not really do much for me. It’s one of those definitions that I imagine if I ask 10 atmospheric scientists to tell me what it means, I will get 12 answers. Therefore, I will draw a picture.

Figure 1: Adapted from Jim Hurrell – This picture is a schematic representation of the positive and negative phases of the Arctic Oscillation. In the positive phase the pressure is low at the pole and high at middle latitudes. This is the positive phase because if you calculate the difference between middle and high latitudes it is large. In the negative phase the pressure is not as low at the pole and not as high at middle latitudes. This is the negative phase because if you calculate the difference between middle and high latitudes it is small. The refrigerator suggests that this is like opening and closing the refrigerator door (see Behavior).

This figure helps me with the definition. I want to focus on the low pressure at high latitudes, which in this figure is drawn idealistically at the pole. In reality, it is likely to wander off the pole, a fact that will be important in the next blog. When the pressure is low at the pole, then there is a stronger vortex of air circulating around the pole. When the pressure at the pole is not as low, then there is a weaker vortex. In both cases, strong or weak vortex, the air generally moves from west to east.

For clarity, vorticity is a parameter that describes rotation in a fluid. A vortex is a feature in a fluid dominated by vorticity – that is it is rotationally dominated. Tornadoes and hurricanes are weather features that we often call vortices; there is an obvious circulation of air in these features. In the Earth’s atmosphere at middle and high latitudes rotation is an important characteristic of the flow, due to the rotation of the Earth. The reason air moves in the west to east direction for both the weak and strong vortex cases of Figure 1 is that the rotation of the Earth is important to the flow.

In Figure 2 I have set up an even more idealized figure. I also provide this link to a Powerpoint animation, that I am not smart enough to incorporate into the blog. In the animation I have five slides that clarify the point that I make in Figure 2.

Figure 2: A vortex and a ball. In the center of the figure is low pressure, meant to be an analogue to the vortex over the pole in Figure 1. Parcels of air move around the low pressure system. If it takes the same amount of time for a parcel farther away from the low pressure center to go around the vortex as a parcel nearer the center, then the parcel farther away has to go faster because the distance it has to go is longer. That is why I drew that arrow, saying that air moves “faster” at the outside edge of the vortex.

To set my point a little more, imagine you are on a bridge overlooking a running stream. If you drop a stick in the water near the edge where the water is moving slowly, then if the stick drifts towards the more rapidly flowing water, it is carried downstream at the edge of the fast moving water. It does not cross the core of fast moving water – this jet of water. In fact the jet is something of a barrier that keeps material from crossing the stream. Material is transported downstream.

Back to Figure 2: Imagine that you want to roll a ball into the center of a vortex. As the ball gets to the edge it gets caught up in the flow and pulled around the edge. It does not roll into the center. Look at the this link to a Powerpoint animation to get a better idea of what’s going on.

Now go back to Figure 1. The vortex in Figure 1 is also a barrier. The southern edge of vortex is a jet stream. Air on the two sides of the vortex often has different characteristics. Intuitively, there is colder air on the poleward side. 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 air on one side is largely separated from the air on the other side. In the next blog, I will describe the difference between the strong and the weak case and its relevance to weather, climate and, perhaps, climate change.

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 401. Neapolitan 1:41 PM GMT on October 14, 2013 Quoting 398. Xulonn:So you prefer more articulate, intelligent and reasoned TV luminaries like Glenn Beck, Bill O'Reilly and Sean Hannity, who use researched facts and let guests with opposing ideas freely talk about them without interruption or ridicule - in contrast to that dumb Rachel Maddow who just makes things up and gets really nasty with her guests?Let's compare:--Hannity: Two-time College drop-out (NYU; Adelphi)--Beck: high school graduate--Maddow: Graduate of Stanford (BA in Public Policy) and Oxford (Rhodes Scholar; PhD in Politics)Yeah, I can see the appeal of the first two to a certain part of the political spectrum... Member Since: November 8, 2009 Posts: 4 Comments: 12465
 402. Xulonn 1:47 PM GMT on October 14, 2013 Quoting 378. tramp96:I think that our effect on the weather is overstated by climate scientists. The reason I post so much is what I hear from the GWers is whining but the first time you take their heat or car ect. away they will be the first ones to cry. I believe carbons were put here as a stepping stone on our way to bigger and cleaner things. We are getting closer to fusion and will get there one day in the mean time I don't believe that we are having the effect climate scientists would like us to think we are.I edited your quote to reflect reality - the changes are in bold type. You can use it as a guideline to avoid looking bad in the future.Also, who took away cars and heat from "GWers and made them whine?You really should learn to distinguish between climate scientists and laypersons who might inject their "opinions" and "feelings" into the argument - which is what you are doing. What you "believe" or "think," unless backed up with intelligent reasoning and data, is essentially worthless, and will get you smacked down repeatedly here. This is a site to discuss climate science and AGW/CC, not a forum to argue whether it exists - that is a known fact and the basis for the existence of this forum.Unless of course, you are smarter and more knowledgeable than Dr. Masters, Dr. Rood and tens of thousands of scientists around the world. They have come to a consensus based on hard science. They are the people you need to rebut - not the laypersons you call "GWers." So bring some science (and not pseudo-scientific claptrap) into your comments, and you will treated with respect, and your questions will be answered politely. Member Since: June 11, 2012 Posts: 0 Comments: 836
 403. Naga5000 1:49 PM GMT on October 14, 2013 Quoting 378. tramp96:I think that our effect on the weather is overstated by GW alarmists. The reason I post so much is what I hear from the GWers is whining but the first time you take their heat or car ect. away they will be the first ones to cry. I believe carbons were put here as a stepping stone on our way to bigger and cleaner things. We are getting closer to fusion and will get there one day in the mean time I don't believe that we are having the effect GWers would like us to think we are.I really wanted you to not dodge the question. Member Since: June 1, 2010 Posts: 3 Comments: 1727
 404. yoboi 1:52 PM GMT on October 14, 2013 Quoting 401. Neapolitan:Let's compare:--Hannity: Two-time College drop-out (NYU; Adelphi)--Beck: high school graduate--Maddow: Graduate of Stanford (BA in Public Policy) and Oxford (Rhodes Scholar; PhD in Politics)Yeah, I can see the appeal of the first two to a certain part of the political spectrum...why did you leave Bill O'Reilly out?????? Member Since: August 25, 2010 Posts: 5 Comments: 634
 405. yoboi 2:11 PM GMT on October 14, 2013 Quoting 403. Naga5000:I really wanted you to not dodge the question.I don't think the person dodged the question....might have not said what you all would like to hear....why is it that you all attack someone who has a different view????? Member Since: August 25, 2010 Posts: 5 Comments: 634
 406. Xulonn 2:14 PM GMT on October 14, 2013 Quoting 394. JohnLonergan:Robust twenty-first-century projections of El Niño and related precipitation variabilityI truly dread the next strong El Nino. The gap between the last strong El Nino in 1997-1998 (the strongest in the record that goes back to 1951) and today has provided fodder for the denialist community. They use it as a starting point for their bogus trend charts. It seems that climate records - time series - that do not include at least a couple of La Ninas and El Ninos are invalid and skewed. The influence of those events really makes the 30-year minimum for climate trends seem logical - and more likely to be statistically valid. As I have asked before, if it's fair to use a 15 year period starting with a strong El Nino to determine the trend - as denialists do - would it then be fair to 1998 to 2001 La Nina as a starting point after the next strong El Nino? (Actually not, but it will be fun to watch them protest when that time comes and we serve them a dose of their own b.s.) Member Since: June 11, 2012 Posts: 0 Comments: 836
 407. Naga5000 2:24 PM GMT on October 14, 2013 Quoting 405. yoboi:I don't think the person dodged the question....might have not said what you all would like to hear....why is it that you all attack someone who has a different view?????Stop making generalizations...I asked a simple question based on the article, I did not receive any answer as to that question. Why do you feel the need to get yourself involved? This doesn't have anything to do with you nor your interpretation of said events. Member Since: June 1, 2010 Posts: 3 Comments: 1727
 408. tramp96 2:34 PM GMT on October 14, 2013 Quoting 407. Naga5000:Stop making generalizations...I asked a simple question based on the article, I did not receive any answer as to that question. Why do you feel the need to get yourself involved? This doesn't have anything to do with you nor your interpretation of said events.I'm working so I don't have a lot of time to answer but quickly I did not say Rachel was stupid I said I didn't like her attitude I can say the same thing about Hannity I rarely watch him. Member Since: August 15, 2009 Posts: 0 Comments: 645
 409. Naga5000 2:39 PM GMT on October 14, 2013 Quoting 408. tramp96:I'm working so I don't have a lot of time to answer but quickly I did not say Rachel was stupid I said I didn't like her attitude I can say the same thing about Hannity I rarely watch him.I meant regarding the science behind climate change. Not the Rachel stuffs. :) Your issue is with "alarmism" and not necessarily the processes of CO2 - energy imbalance - warming world. Is this a correct assessment? Member Since: June 1, 2010 Posts: 3 Comments: 1727
 410. JohnLonergan 2:40 PM GMT on October 14, 2013 From The ConversationAustralia to see worse drought thanks to intensifying El Niño ...Dr Wenju Chai from CSIRO, who did not contribute to the research, said that the paper is significant in that there is a stronger agreement between different climate models in predicting the future impact of El Niño.“Up until now, there has been a lack of agreement among computer models as to how ENSO will change in the future.”“During El Niño, Western Pacific countries (Australasia, including Australia) experience unusually low rainfall, while the eastern equatorial Pacific receives more rainfall than usual. This study finds that both the wet and dry anomalies will be greater in future El Niño years. This means that ENSO-induced drought and floods will be more intense in the future.” Member Since: June 27, 2012 Posts: 0 Comments: 1797
 411. Naga5000 2:46 PM GMT on October 14, 2013 Tramp96, if you would like to continue the conversation through WU mail due to scheduling difficulties, that would be great. Just drop me a line. Member Since: June 1, 2010 Posts: 3 Comments: 1727
 412. tramp96 2:55 PM GMT on October 14, 2013 Quoting 411. Naga5000:Tramp96, if you would like to continue the conversation through WU mail due to scheduling difficulties, that would be great. Just drop me a line.Ok Member Since: August 15, 2009 Posts: 0 Comments: 645
 413. Neapolitan 2:59 PM GMT on October 14, 2013 Quoting 406. Xulonn:I truly dread the next strong El Nino. The gap between the last strong El Nino in 1997-1998 (the strongest in the record that goes back to 1951) and today has provided fodder for the denialist community. They use it as a starting point for their bogus trend charts. It seems that climate records - time series - that do not include at least a couple of La Ninas and El Ninos are invalid and skewed. The influence of those events really makes the 30-year minimum for climate trends seem logical - and more likely to be statistically valid. As I have asked before, if it's fair to use a 15 year period starting with a strong El Nino to determine the trend - as denialists do - would it then be fair to 1998 to 2001 La Nina as a starting point after the next strong El Nino? (Actually not, but it will be fun to watch them protest when that time comes and we serve them a dose of their own b.s.)Of course, then the ignorati will say that the temperatures are so high only because of the El Nino. Or, they'll take the peak of the '98 EN spike, compare that to the next one, and say, "See? It hasn't warmed up that much, has it?" Member Since: November 8, 2009 Posts: 4 Comments: 12465
 414. yoboi 3:03 PM GMT on October 14, 2013 Quoting 407. Naga5000:Stop making generalizations...I asked a simple question based on the article, I did not receive any answer as to that question. Why do you feel the need to get yourself involved? This doesn't have anything to do with you nor your interpretation of said events.just like when I ask neap a question and all the hens jump in to answer for him......so I am just doing what you all do.... Member Since: August 25, 2010 Posts: 5 Comments: 634
 415. JohnLonergan 3:15 PM GMT on October 14, 2013 International climate agreements? There must be a better way With the release Friday of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report of the state of climate science, the message has never been clearer: we have to do something to get the world’s greenhouse gas emissions down. But the international legal framework for addressing the climate change problem – the United Nations Framework Convention on Climate Change (UNFCCC) and its Kyoto Protocol – has not worked.At Doha late last year, Kyoto parties determined that a second “commitment period” would start at the beginning of 2013 and end at the end of December 2020.This second commitment period will cover barely 15% of global emissions. It will include no major emitter. Targets may not increase; we won’t know until the end of the year, perhaps even later.At Durban in 2011, a non-binding “agreement to agree” on the development of “a protocol, another legal instrument or an agreed outcome with legal force” under the UNFCCC and applicable to all parties – both developed and developing – was launched. It will take effect from 2020.It now appears that an end of 2015 “deal” for implementation in 2020 may not be possible.It is a classic collective action problem.As Lawrence Summers, a former US Treasury Secretary and Harvard President has said, “considerable imagination will be required as to how agreements can be made attractive to the major developing countries or made to be effective without their participation.”Read on>> Sub-national action: more substance, less form Member Since: June 27, 2012 Posts: 0 Comments: 1797
 416. JohnLonergan 3:20 PM GMT on October 14, 2013 Could sectoral agreements solve climate change? This is part two of a three-part series that follows on from the release of the Intergovernmental Panel on Climate Change Fifth Assessment Report, looking at emerging alternatives to the UN climate agreement process.Since the climate change problem emerged as a major international issue in the late 1980s, a recurring policy question has been whether to address it comprehensively or industry sector by industry sector.The United Nations and its Kyoto Protocol adopt a comprehensive, global approach. But neither agreement precludes sectoral approaches. Indeed, the Kyoto Protocol says emissions reductions from aviation and shipping should be agreed by those sectors.Sectoral agreements and their advantages Member Since: June 27, 2012 Posts: 0 Comments: 1797
 417. JohnLonergan 3:24 PM GMT on October 14, 2013 Fixing climate change: the future isn’t what it used to beThis is the last part of a series following on from the release of the Intergovernmental Panel on Climate Change Fifth Assessment Report and looking at emerging alternatives to the UN climate agreement process.State based action and sectoral agreements show some promise in dealing with aspects of climate change. But from humanity’s climate change experience to date and its failure to address the climate change problem through a global agreement, it’s safe to suggest we are headed for trouble.Given our current path on generating and dealing with emissions, here are my predictions for the future of climate change and climate change action.Individual action doesn’t and won’t matter Member Since: June 27, 2012 Posts: 0 Comments: 1797
 418. barbamz 3:28 PM GMT on October 14, 2013 Expanding the Grid: A Vision for Fueling Europe on RenewablesSpiegel English, Oct 14, 2013, by Christoph PaulyEuropean Energy Commissioner Günther Oettinger is in Brussels on Monday to present his plan for the future of energy in the EU. He wants to export Germany's push toward renewables to the rest of the Continent -- and for the first time, he actually has the money to do it. ... Member Since: October 25, 2008 Posts: 34 Comments: 4013
 419. JohnLonergan 3:45 PM GMT on October 14, 2013 Member Since: June 27, 2012 Posts: 0 Comments: 1797
 420. WunderAlertBot (Admin) 4:22 PM GMT on October 14, 2013 RickyRood has created a new entry.

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