Are the changes in the Arctic messing with our weather? Background

By: Dr. Ricky Rood , 4:02 AM GMT on January 14, 2014

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Are the changes in the Arctic messing with our weather? Background

(20140115: Revision: This is a revision. In the comments on the original post rlk and ScottLincoln questioned the magnitude of the pressure change in the figure used in the paper. I wrote Kevin Trenberth, the author, and he confirms that the units should be pascals, not hectopascals. I thank rlk and ScottLincoln, and indeed, I should have flagged this as well, rather than noting how large it was and moving along in the original post. The conclusions in the blog are not altered.)

This entry continues with my listing of the big-ticket items in climate change since I last taught in April 2012. In the last entry I wrote about how the technology used to extract oil and natural gas, hydraulic fracturing (fracking), stood as a threat to climate change because it assured the availability of fuels that we preferred and, also, provided desirable jobs. Some would argue that fracking might diminish our use of coal, which is a good thing. This is likely true, but there are several issues that need to be analyzed in that conclusion: selling our coal to other countries, the complete accounting of greenhouse gases associated with fracking, the broader environmental consequences of fracking, the fact that there are no real disincentives for using fossil fuels, and the fact that all burnt fossil fuels have a long-term cumulative effect (My Michigan colleagues integrated assessment of fracking). I don’t want to diminish the importance that the carbon dioxide emissions in the U.S. have, perhaps, been decreasing in recent years; however, it is not a fact that suggests we are on a path to addressing the problems of climate change. I assert we remain in a situation where economic growth, which we require for well-being, is still strongly linked to energy use and carbon emissions. If our economy grows so will our emissions as the preliminary 2013 emissions suggest.

The second big-ticket item that I want to highlight is the work investigating the changes in the Arctic and the possibility that these changes are already influencing the weather in the continental U.S. and, more broadly, in the Northern Hemisphere. I have written about this extensively in my series on the Arctic Oscillation and the hot and cold fluctuations in the U.S. (link to last in series, also see links below). I take some pleasure in noting that back in December I wrote, “The whole Arctic air mass is starting to move east, which means it will get a lot more press.” I did not imagine that it would lead to all of the anxiety about the rogue polar vortex (We the geeks).

I will leave the machinations of polar-vortex mania to my more able colleagues. I want to analyze why this work about the Arctic Oscillation, the polar vortex and wild fluctuations between warm and cold weather is important enough to be on my list of big-ticket items.

There is little controversy that there have been massive changes in the climate of the Arctic. These are most easily noted in the large changes in Arctic sea ice. There is also a whole set of coherent and convergent evidence that documents the changes in the Arctic. The most direct evidence is the increase in temperature, which is much greater in the Arctic than at lower latitudes and in the tropics (Polar or Arctic amplification). Coincident with this warming is a lengthening of the growing season and an increase in activity in the northern forests – the greening of the Arctic (200 blogs ago, Getting Ready for Spring 5). There is controversy about whether these changes in the Arctic are causing changes to the weather at lower latitudes. There is also controversy about if there is a change in the weather at lower latitudes, is it due to the local changes in the Arctic such as loss of sea ice.

I want to start the discussion with Figure 11 from a paper by Kevin Trenberth and John Fasullo entitled, An apparent hiatus in global warming? I will write more about this paper in a future blog. Trenberth and Fasullo provide a self-consistent global analysis that tracks the heating of the planet. Figure 11 of this paper shows the difference in average sea-level pressure between two time periods. An average is taken for 1999-2012 and another for 1979-1998. The difference between the two averages shows an increase in sea-level pressure. This increase is represented by the large red area stretching from the North Atlantic, east of Greenland, to the Arctic Ocean and centered over the North Pole. The maximum magnitude of this increase is about 150 Pa (pascal). To put this in perspective the surface pressure of the Earth is often cited as being 1000 hPa (hectopascal).



Figure 1: Mean annual sea-level pressure differences from ERA-Interim Reanalysis for 1999–2012 and 1979–1998 in Pa (pascal, colors) and for surface wind vectors (arrows) in meter per seconds with the key at top right. (a) Map projection centered on the Pacific and (b) polar stereographic projection of the Northern Hemisphere. (Note the magnitude of pressure is in Pa, not hPa, which is a typo in the original manuscript.)(Figure 11 from An apparent hiatus in global warming?)

This increase in the Arctic sea-level pressure can also be viewed in terms of the strength of the polar vortex, or in terms of wind, the strength of the rotation of the wind. Low pressure is associated with a strong vortex with strong rotation; high pressure is associated with a weak vortex with less rotation (earlier blog on strong and weak vortex). Hence, the observations show that there is a weaker polar vortex. As measured in terms of the Arctic Oscillation, the Arctic Oscillation is more negative. From our narrow U.S. perspective, this is associated with cold and snowy conditions over the eastern half of the U.S. leading to exaggerated political and press attention and excess purchase of toilet paper and bread in supermarkets from Atlanta northwards. It is quite easy to conclude that for the past decade and a half the Arctic Oscillation has been more prominently in its negative phase.

The analysis of Trenberth and Fasullo comes to the conclusion that this change in the Arctic is the consequence of changes in the global distribution of mass of the atmosphere. Specifically, Trenberth and Fasullo trace the changes in the Arctic back to changes in the tropics. Placing the Arctic changes as a part of a global circulation change stands in tension to the conclusions of Jennifer Francis and her collaborators, who are quoted extensively in my blogs. Francis and Vavrus (2012) in Evidence linking Arctic amplification to extreme weather in mid-latitudes correlate the changes in sea-level pressure to changes in the sea ice, the Arctic Oscillation and snow cover. This is a focus on a direct local effect in the Arctic causing changes in the global circulation.

The work that I cite above, in all cases, points to a time in the past 15 years where the Arctic Oscillation is often in its negative phase. There is a difference between the researchers in the determination of cause and effect. The difference in cause and effect leads, perhaps, to different conclusions about the future. The question: in the future will the Arctic Oscillation be more prone to its negative phase? With that question, I introduce another paper, by Elizabeth Barnes and co-authors Revisiting the evidence linking Arctic amplification to extreme weather in midlatitudes. Barnes et al. analyze the simulations used in the most recent Climate Model Intercomparison Project (CMIP-5) and conclude that the models do not support the conclusion that the Arctic Oscillation will become more negative in the future.

In the next blog, I will discuss the arguments offered by these different researchers. Then I will provide my analysis of why I conclude that what is happening in the Arctic makes it to my list of the big-ticket items of the past year.

r


Cold Weather in Denver: Climate Change and Arctic Oscillation (8)

Climate Change and the Arctic Oscillation 2

Climate Change and the Arctic Oscillation 1

Wobbles in the Barriers

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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1226. Xulonn
Quoting 1204. AGWSpecialist:

The link still stands, since I still have not seen anything scientific to refute. I haven't given up on you yet...
Classic denialist tactics as promoted by the right-wing think tank denialist training materials from places such as the Heritage Foundation.

"Claim that a point that has indeed been thoroughly refuted has not been refuted."

What you haven't given up on is persistence in pushing a falsehood.
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1224. Xulonn
Quoting 1203. AGWSpecialist:
I read this thread and see many people who disagree with AGW. And many people disagree with it. Remember Daisy World's article. It's up to 27% of the general public. It was lower, but now came up. Surely those people have an opinion on it and are not uninformed as you suggest.
Most all of the scientists in the world, and every significant and respected scientific association in the world support AGW/CC, and indeed, are focused on studying this monstrously complex issue and looking at possible mitigation measures.

The opinions of the misinformed have no substance. They are being suckered by the media who are looking for controversy where there is none - and it's not only Fox News...

Or they are suffering from denial related issues based on the not wanting to face the negative impacts that are coming...

Or they are swallowing the b.s. being fed to them via the media - including the internet, the capitalist "maximize profits at all costs" crowd, and the FF industry and conservative think tank funded AGW/CC denialist industry...

Or a combination of the above.

The basis of illogical AGW/CC denialism is quite clear to those who are aware enough to look at reality and think critically.
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Quoting 1215. Birthmark:

It's doubly laughable when one considers that the most recent solar minimum was the lowest in over one hundred years, and the current maximum is pretty weak...yet temperatures haven't fallen. Quite the contrary. lol

Todays CO2 levels are high enough to overide solar and prbital forcings for about 100,000 years. No need to be concerned about cooling until CO2 is back down to preindustrial levels.
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Quoting 1215. Birthmark:

It's doubly laughable when one considers that the most recent solar minimum was the lowest in over one hundred years, and the current maximum is pretty weak...yet temperatures haven't fallen. Quite the contrary. lol

SC 24 has been nothing short of pathetic. From what I understand, SC 23 had a fairly normal maximum, and you can see how it dwarfs our current solar cycle at their respective maximums.



Sure, there's room for the next cycle to go even lower, and it probably will, but one would think that with the massive decline in solar activity over the past 10 years or so there would be at least some evidence of a cooling planet if solar cycles are indeed a dominant force on Earth's climate.
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Quoting 1212. yoboi:



please archive it....


I don't have to...unless for some mysterious reason you get banned, all of your comments will remain here just as you typed them.
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Quoting 1195. martinitony:

So, you believe what exactly, that there is 95% certainty as to there being global warming, 95% certainty that it is AGW and then with trillions of dollars at risk and entire life changes necessary, that that certainty says do something now?
I'm thinking even if warming is certain, AGW is not and even if you were just as certain about that, 95%, I'd prefer to wait for 99% before I change my way of life and vote to spend trillions.
There is no proof nor any science that provides us with proof that waiting another 10 -15 years before taking the actions so many of you want, will matter. And then you might have your certainty at 99%.
I suspect we are going to get that time and I hope the Russians are right.


The way one of my Methods professors like to described uncertainty, mainly at the 95% level, was "It someone told you the Cowboys were 95% certain to win Sunday's game, who here is gonna put $500 on the Giants?".

Essentially arguing about the 95% level of certainty goes way beyond climate science and social science. Every group that uses statistics generally uses the .05 level. The reason being is in standardized tests the z score is a nice -1.96 to 1.96 for the .05 level. Makes the math simple.

We could definitely use the .01 level for these statistical tests. I'm pretty sure the same results would occur, although we may need to nudge that number of years up some more depending.

As for taking actions, my premise has always been simple. Regardless of warming, fossil fuels are a finite resource. Let's start the weening process now.
Member Since: June 1, 2010 Posts: 4 Comments: 5283
Is it evident guys, or do I need to come to each one of y'alls houses and ring a bell in your ears. :D

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Quoting 1186. yoboi:
The importance of Solar Cycle 25. Why the next Dalton Minimum could be sooner than you think. Another climate change is on the way, learn to adapt.



Link


*Heavy Audible Sigh*

I can't wait for SC25 to pass to make all of your comments on this particular area look even more laughable than they currently are.
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Quoting 1190. AGWSpecialist:

Your NWS vest is in clear view in your avatar on a weather forum.

Clearly, I'm aware. I'm the one that clicked "upload."
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Quoting 1173. MAweatherboy1:

Because of people like you who conveniently choose to ignore it. Lol.
You just won the internet.
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Quoting 1162. Naga5000:


In generalized terms, yes 60 years would be better than 30 years. However, due to the way the math works out as described in JohnLonergan's post#1124, there is mathematically no reason to go beyond that approximate 30 (for his data set it was 24). You'll be hard pressed to find a data set in this regard where 30 will not get you significant results at the .05 level. The only reason to go beyond those 30 would be a case in which there would be no significance at that level. In that case more data points would be needed.

So, while you certainly can use a 60 year data set, there is actually no need to do so. I most definitely trust 34 years. There is no reason not to, even given the variability.

So, you believe what exactly, that there is 95% certainty as to there being global warming, 95% certainty that it is AGW and then with trillions of dollars at risk and entire life changes necessary, that that certainty says do something now?
I'm thinking even if warming is certain, AGW is not and even if you were just as certain about that, 95%, I'd prefer to wait for 99% before I change my way of life and vote to spend trillions.
There is no proof nor any science that provides us with proof that waiting another 10 -15 years before taking the actions so many of you want, will matter. And then you might have your certainty at 99%.
I suspect we are going to get that time and I hope the Russians are right.
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1193. Xulonn
Quoting 1173. MAweatherboy1:

Because of people like you who conveniently choose to ignore it. Lol.
Oh man! The cavalry just rode over the hill - reinforcements are here.

Welcome MAweatherboy!
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Quoting 1184. Birthmark:

I've yet to see a green energy company post here.
Hey Birthmark,Did you see VW came out with a car that gets 292 mpg hwy? That will change alot of things!
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Quoting 1162. Naga5000:


In generalized terms, yes 60 years would be better than 30 years. However, due to the way the math works out as described in JohnLonergan's post#1124, there is mathematically no reason to go beyond that approximate 30 (for his data set it was 24). You'll be hard pressed to find a data set in this regard where 30 will not get you significant results at the .05 level. The only reason to go beyond those 30 would be a case in which there would be no significance at that level. In that case more data points would be needed.

So, while you certainly can use a 60 year data set, there is actually no need to do so. I most definitely trust 34 years. There is no reason not to, even given the variability.


One point, 30 years was selected by the World Meterological Organization approximately 80 years ago as the time needed to establish a climatic trend and it continues to be the accepted value.
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Quoting 1181. AGWSpecialist:

I just said I agree with you that a 30 year threshold should be used. There is no putting people's words in other's mouths as you say.

Do not take me for a fool. I've been watching the blog comment thread, and I know exactly what you are trying to do. Your M.O. is not a secret.
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Quoting 1181. AGWSpecialist:

I just said I agree with you that a 30 year threshold should be used. There is no putting people's words in other's mouths as you say.
Good point!
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Quoting 1172. Xulonn:
I think I understand what you mean by an "all-time" low. So rather than nit-picking and playing "gotcha" like denialists often do, I take it that you mean modern records.

It actually means that there is what Dr. Masters calls "whiplash weather" with a few more low temp records and a lot more high temp records.

AGW/CC does not preclude cold records. While global averages for temperatures increase, the number of both minimum and maximum records can increase, but globally,, the maxes are winning.

Also be aware that a thousand calibrated thermometers in one county could show a thousand record lows, so that would have to be considered, and would not offset an equivalent warmer area with only ten thermometers. The areal or spacial distribution of official weather stations is often not included when discussing temperature records outside of scientific circles.

So be aware that a large number of records in a small geographical area is actually not significant.
Well,I think it's funny! I have been saying that same thing "since records been kept" . Keep up the good work here,Xulonn!
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1180. Xulonn
Quoting 1151. AGWSpecialist:

You sure have a hard on for me. Why?
Honest answers to such queries from denialist commenters are strictly forbidden by WU Rules of the Road.
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Quoting 1174. Birthmark:

Because the public, by and large, aren't scientists. They frequently misinterpret the science, leading them to false conclusions...which they will, seemingly, defend to the death.


Not to mentioned the paid for google search positions from our favorite denial/conspiracy websites.
Member Since: June 1, 2010 Posts: 4 Comments: 5283

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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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