# Barriers in the Atmosphere: Arctic Oscillation (3)

By: Dr. Ricky Rood , 12:50 AM GMT on October 03, 2013

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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##### 419. JohnLonergan
Member Since: June 27, 2012 Posts: 0 Comments: 4339
##### 418. barbamz
 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: 73 Comments: 8460
##### 417. JohnLonergan
 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: 4339
##### 416. JohnLonergan
 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: 4339
##### 415. JohnLonergan
 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
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##### 413. Neapolitan
 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?"
##### 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.
Member Since: June 1, 2010 Posts: 4 Comments: 5411
##### 410. JohnLonergan
 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: 4339
##### 409. Naga5000
 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: 4 Comments: 5411
##### 407. Naga5000
 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: 4 Comments: 5411
##### 406. Xulonn
 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: 1774
##### 403. Naga5000
 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: 4 Comments: 5411
##### 402. Xulonn
 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: 1774
##### 401. Neapolitan
 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...
##### 399. Xulonn
 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.Aha! So you don't believe in science? Or do you simply not understand it? Did you do well in your high school and college science classes? Did you even take any?
Member Since: June 11, 2012 Posts: 0 Comments: 1774
##### 398. Xulonn
 Quoting 373. tramp96:Sorry man I try to watch her so I can see both sides but I can't take her attitude. It's like she watched Oberman for years and then became a female him.Read this please.LinkSo 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?
Member Since: June 11, 2012 Posts: 0 Comments: 1774
##### 397. Daisyworld
 Quoting 393. tramp96:You are both very short sighted.Either start defining your terms (e.g., "lib", "short sighted") and explain why you are here, or please stop posting. You've technically served an ad hominem twice now without explaining yourself, and that's breaking the community rules. Nothing you've written has added anything to the conversation about climate change or the topic of Dr. Rood's blog entry, and at the moment, it looks like you're simply trolling for an argument.
##### 396. JohnLonergan
 IPCC Report Shows Action on Climate Change Is Critical"The Intergovernmental Panel on Climate Change just released the first of four chapters of its Fifth Assessment Report. It shows scientists are more certain now than in 2007 when the Fourth Assessment was released that humans are largely responsible for global warming—mainly by burning fossil fuels and cutting down forests—and that it’s getting worse and poses a serious threat to humanity. It contains hints of optimism, though, and shows addressing the problem creates opportunities."
Member Since: June 27, 2012 Posts: 0 Comments: 4339
##### 395. JohnLonergan
 Inconvenient Uncertainties"The world is a messy place. The scientific method imposes some order, but in the case of climate change, that order is probabilistic. For the sake of science and the planet, we should not become distracted by a false sense of certitude. Imprecise truths are the most inconvenient ones. We know enough to act now. What we don’t know should prompt us to even more decisive action. "Read more >>
Member Since: June 27, 2012 Posts: 0 Comments: 4339
##### 394. JohnLonergan
 Robust twenty-first-century projections of El Niño and related precipitation variability>The El Niño–Southern Oscillation (ENSO) drives substantial variability in rainfall1, 2, 3, severe weather4, 5, agricultural production3, 6, ecosystems7 and disease8 in many parts of the world. Given that further human-forced changes in the Earth’s climate system seem inevitable9, 10, the possibility exists that the character of ENSO and its impacts might change over the coming century. Although this issue has been investigated many times during the past 20 years, there is very little consensus on future changes in ENSO, apart from an expectation that ENSO will continue to be a dominant source of year-to-year variability9, 11, 12. Here we show that there are in fact robust projected changes in the spatial patterns of year-to-year ENSO-driven variability in both surface temperature and precipitation. These changes are evident in the two most recent generations of climate models13, 14, using four different scenarios for CO2 and other radiatively active gases14, 15, 16, 17. By the mid- to late twenty-first century, the projections include an intensification of both El-Niño-driven drying in the western Pacific Ocean and rainfall increases in the central and eastern equatorial Pacific. Experiments with an Atmospheric General Circulation Model reveal that robust projected changes in precipitation anomalies during El Niño years are primarily determined by a nonlinear response to surface global warming. Uncertain projected changes in the amplitude of ENSO-driven surface temperature variability have only a secondary role. Projected changes in key characteristics of ENSO are consequently much clearer than previously realized.
Member Since: June 27, 2012 Posts: 0 Comments: 4339
##### 391. JohnLonergan
 Quoting 390. goosegirl1:belief: trust, faith or confidence in something or someonefact: something that truly exists or happensLearn the difference."Faith: not wanting to know what is true."(Friedrich Nietzsche / 1844-1900)
Member Since: June 27, 2012 Posts: 0 Comments: 4339
##### 390. goosegirl1
 Quoting 383. tramp96:Maybe watching to much Star Trek as a kid but I think we are meant to discover and achieve and one day explore space. If you are asking if I believe in God the answer is yes. belief: trust, faith or confidence in something or someonefact: something that truly exists or happensLearn the difference.
##### 389. BaltimoreBrian
 Hermes unveils line of \$11,000 bicyclesFor the environmentally conscious among the 1%. The updated 'limousine liberal' ;)
Member Since: August 9, 2011 Posts: 26 Comments: 11054
##### 388. BaltimoreBrian
 As in Elizabeth (Libby) Dole?Wait did I say 'dole'? :P
Member Since: August 9, 2011 Posts: 26 Comments: 11054
##### 387. VR46L
 Quoting 385. Daisyworld:"Lib friend"? Pray tell, what do you define as a "lib", sir/ma'am?A short form of Elizabeth ...as in Libby :)
##### 386. BaltimoreBrian
 Quoting 385. Daisyworld:"Lib friend"? Pray tell, what do you define as a "lib", sir/ma'am?The opposite of a 'con', perhaps?And no, I'm not a liberal. I've voted Republican in 5 of the last 7 presidential elections. And in other topics I have a feeling that many of the other commenters here would disagree with me. But if the tea party crazies who have emerged the past few years keep dominating the Republican party then moderates like me will not feel welcome in it. The hard right will always vote Republican. But they need people like me to win. You can't win without us RINOSRepublicans need us but we moderates don't need them. And without us you lose.
Member Since: August 9, 2011 Posts: 26 Comments: 11054
##### 385. Daisyworld
 Quoting 384. tramp96:No to use your terms I find it highly offensive that you choose to lecture me and not your lib friend when he, again using your terms was quite rude in referring to me in that manner. Why don't you let him fight his own battles."Lib friend"? Pray tell, what do you define as a "lib", sir/ma'am?
##### 382. ScottLincoln
 Quoting 380. tramp96:Go lecture someone else lib.I see that at this point, you are specifically asking to have your account banned. That's what happens when you provide no meaningful discussion and resort to ad hominem attacks. It might make you feel good to internet-bully others, but it really just speaks more about you when you choose to do so against someone who knows quite a bit about the topic at hand.You were provided with friendly advice beforehand, so be aware that all subsequent consequences are yours and yours alone.
Member Since: September 28, 2002 Posts: 5 Comments: 3480
##### 381. ScottLincoln
 Quoting 378. tramp96:I think that our effect on the weather is overstated by GW alarmists. What is a "GW alarmist?"Quoting 378. tramp96:[Ad homenem attack][CO2 is supposed to be burned for a divine reason][Fusion power will be developed before we need to act]None of these claims deserves a response.Quoting 378. tramp96:I don't believe that we are having the effect GWers would like us to think we are.You said you "don't believe" humans are having the effect on climate that climate scientists claim. It seems as though you may need a refresher on a century or so of work in the geosciences. Until you remedy that, people in a climate-science-specific blog are unlikely to take you seriously.What you call "GW" (specifically anthropogenic global warming) is simply the net result of the following chain of concepts:* Humans burn fossil fuels.* Burning fossil fuels produces CO2.* About half of that CO2 remains in the atmosphere.* Adding CO2 to the atmosphere raises its concentration.* CO2 in the atmosphere absorbs longwave infrared radiation.* The earth's energy budget is determined by the balance between absorbed shortwave solar radiation minus emitted longwave infrared radiation.*In the absence of positive or negative feedbacks, increasing the concentration of CO2 in the atmosphere reduces outgoing longwave radiation and raises the temperature by 1C per doubling.*The record of past climate changes (e.g., glacial/interglacial cycles) shows that net feedbacks within the earth system are not sufficiently negative to prevent large swings in climate.Every one of these is well established, from chemistry or physics to the geosciences. Each of these concepts adds up to "AGW".Which specific part of the process do you "disbelieve"?
Member Since: September 28, 2002 Posts: 5 Comments: 3480
##### 379. BaltimoreBrian
 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.On what do you base your belief?
Member Since: August 9, 2011 Posts: 26 Comments: 11054
##### 377. RevElvis
 "Carlo Maria Cipolla, an economic historian, is famous for his essays about human stupidity, such as "The Basic Laws of Human Stupidity". He viewed stupid people as a group, more powerful by far than major organizations such as the Mafia and the industrial complex, which without regulations, leaders or manifesto nonetheless manages to operate to great effect and with incredible coordination.These are Cipolla's five fundamental laws of stupidity:1. Always and inevitably each of us underestimates the number of stupid individuals in circulation.2. The probability that a given person is stupid is independent of any other characteristic possessed by that person.3. A person is stupid if they cause damage to another person orgroup of people without experiencing personal gain, or even worsecausing damage to themselves in the process.4. Non-stupid people always underestimate the harmful potential ofstupid people; they constantly forget that at any time anywhere, and inany circumstance, dealing with or associating themselves with stupidindividuals invariably constitutes a costly error.5. A stupid person is the most dangerous type of person there is."Stupidity Wiki
Member Since: September 18, 2005 Posts: 30 Comments: 1085
##### 376. ScottLincoln
 Quoting 368. tramp96:No i just know you have many opinions and i just wanted to see what your thoughts were on the difference between the two groups of "forecasters".One group uses scientific evidence and independent verification to prediction based upon assumptions; said prediction has known levels of uncertainty. The other group pulls things out of a hat.One probably shouldn't be called a "forecast" if you intend it to be a factual statement. There is a difference.
Member Since: September 28, 2002 Posts: 5 Comments: 3480
##### 375. ScottLincoln
 Quoting 365. tramp96:No just wondering if you want to control this blog since your not the administrator.Blogs on weatherunderground are also community moderated.Being rude, especially when you are new to a thread, is poor internet etiquette. Continued poor internet etiquette leads to "minused" posts, or ignored user handles. After so many "minuses," your posts get removed from the thread.This blog in particular is used to discuss Dr. Rood's posts, and climate science in general. That's a good place to start.A friendly reminder.
Member Since: September 28, 2002 Posts: 5 Comments: 3480
##### 374. Naga5000
 Quoting 373. tramp96:Sorry man I try to watch her so I can see both sides but I can't take her attitude. It's like she watched Oberman for years and then became a female him.Read this please.LinkUsing this as our starting point, can I take it to mean that you do think that increased CO2 does indeed cause an energy imbalance that results in warming, and that your issue is with "climate alarmism" and not with the basic scientific principles behind climate change?
Member Since: June 1, 2010 Posts: 4 Comments: 5411
##### 372. Naga5000
 Quoting 370. tramp96:Oh man, I thought we were having such a good time...and then...a double insult to a blogger and Rachel Maddow. There goes the neighborhood.
Member Since: June 1, 2010 Posts: 4 Comments: 5411
##### 371. Naga5000
 Quoting 368. tramp96:No i just know you have many opinions and i just wanted to see what your thoughts were on the difference between the two groups of "forecasters".Well then, one group of forecasters use data to run models, those models have a pretty decent track record. Obviously they aren't exact, but they preform well enough to give us a good picture of what to expect. Climatic models looks for averages over time unlike weather models that attempt to predict individual weather events, and therefore, are no that accurate after a few days. LinkLinkAs for Overwash's predictions, he just seems to think there will be a colder than normal winter, or maybe and ice age. I don't know what evidence he has to back it up, however the unscientific Farmer's Almanac seems to think that as well...
Member Since: June 1, 2010 Posts: 4 Comments: 5411

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