by Judith Curry
Is the dramatic decline of Arctic sea ice, spurred by manmade global warming, making the weather where we live more extreme? Several recent studies have made this claim. But a new study finds little evidence to support the idea that the plummeting Arctic sea ice has meaningfully changed our weather patterns.
Arctic ice loss and extreme weather
Last October, a paper was published entitled Arctic ice loss may be making North America weather more extreme. The original NOAA press release is [here]. The basic idea of the paper is summarized in an article by Jason Samenow entitled Study: Arctic ice loss may be making North America weather more extreme. Excerpts:
Before 2007, typical summer winds at the Arctic surface were more variable but tended to flow from the west. Since then, the summer winds were found to blow more consistently from the south, through the Bering Strait, across the North Pole, and out toward the Atlantic Ocean relative to the mean pattern in previous decades.
The shift coincided with the rapid decline of Arctic sea ice.
“This shift demonstrates a physical connection between reduced Arctic sea ice in the summer, loss of Greenland ice, and potentially, weather in North American and Europe,” said James Overland, of NOAA’s Pacific Marine Environmental Laboratory and study lead author.
The resulting meandering flow regime has often favored atmospheric blocking, where weather systems lock in place and get stuck. This means if it’s cold, warm or stormy, such conditions are likely to persist under these circumstances.
Some scientists find this over simplistic:
Take for example, Randall Dole, deputy director for research at NOAA’s Earth System Research Laboratory, who said, “it cannot be assumed that the changes will necessarily make weather worse, at least by some metrics.”
Judah Cohen, a climate forecaster at Atmospheric and Environmental Research in Massachusetts added: “It is not simple to explain how sea ice loss that peaks in August and September impacts the circulation at mid-latitudes [during] December through March.”
This is a topic that I am pretty knowledgeable about (see this previous post on a paper from my research group.) Without going into detail, I certainly agree with the statement that the Overland et al. paper is over simplistic.
One of the paper’s coauthors, Jennifer Francis, has gotten quite a bit of mileage out of this paper. She has been involved with Al Gore’s Climate Reality Project, and was recently invited to give Congressional Testimony (discussed here). Francis has also been the chief proponent of a link between the Arctic sea ice decline and Hurricane Sandy:
Francis, a leading scientist of some of the research linking Arctic amplification and more extreme weather patterns in the mid-latitudes, said the unusual path of Superstorm Sandy may have been a consequence of the connection. The record loss of Arctic ice last fall favored a “block” or extreme slowing in the jet stream over Greenland that pushed Sandy towards the Jersey shore Francis contends.
Disputing the Overland et al. paper
This week, a new paper has been published:
Revisiting the evidence linking Arctic Amplification to extreme weather in midlatitudes
Elizabeth Barnes
Abstract. Previous studies have suggested that Arctic Amplification has 3 caused planetary-scale waves to elongate meridionally and slow-down, resulting in more frequent blocking patterns and extreme weather. Here, trends in the meridional extent of atmospheric waves over North America and the North Atlantic are investigated in three reanalyses, and it is demonstrated that previously reported positive trends are an artifact of the methodology. No significant decrease in planetary-scale wave phase speeds are found except in OND, but this trend is sensitive to the analysis parameters. Moreover, the frequency of blocking occurrence exhibits no significant increase in any season in any of the three reanalyses, further supporting the lack of trends in wave speed and meridional extent. This work highlights that observed trends in midlatitude weather patterns are complex and likely not simply understood in terms of Arctic Amplification alone.
Jason Samenow also reports on this paper, in a post entitled Arctic warming and our extreme weather: no clear link new study finds. Excerpts:
Is the dramatic decline of Arctic sea ice, spurred by manmade global warming, making the weather where we live more extreme? Several recent studies have made this claim.
But a new study finds little evidence to support the idea that the plummeting Arctic sea ice has meaningfully changed our weather patterns. The research, published today in Geophysical Research Letters, says links between declining Arctic sea ice and extreme weather are “an artifact of the methodology” and not real.
But the new research by Colorado State professor Elizabeth Barnes, which examined the waviness of the jet stream over the period 1980-2011, found no changes in its speed and no signs of increased blocking.
“We conclude that the mechanism put forth by previous studies … that amplified polar warming has lead to the increased occurrence of slow-moving weather patterns and blocking episodes, is unsupported by the observations,” Barnes writes.
Is Barnes’ paper the ‘last word’ on this topic? Heck no. But I find it to be an interesting and valuable contribution to the literature on this topic.
Jennifer Francis responds
In yet another post by Jason Samenow, entitled Researcher defends linking Arctic warming and extreme weather, Jennifer Francis responds to Barnes’ paper. Excerpts:
Jennifer Francis, an atmospheric scientist at Rutgers University and leading proponent of the theory, has sent me some comments vigorously defending it.
Her comments are technical, but I’ll try to extract the key points (I reproduce the comments, in their entirety, at bottom of this post).
Francis begins by questioning the motivation of Elizabeth Barnes, the author of the study which claims the link between Arctic warming and extreme weather is “an artifact of the methodology” and “unsupported by the observations.”
She calls Barnes’ approach “less than objective” and “a direct attempt to disprove work” she authored.
Excerpts from Francis’ verbatim comments at the bottom of Samenow’s post.
Questioning motives
I haven’t seen an attack like this on a scientific paper that directly questions the motives of the author since the heyday of the hurricane wars circa 2005 and the publication of the Emanuel and Webster et al. papers.
When I first saw Francis’ statement, I thought wow, what is going on here? Who exactly is this Elizabeth Barnes person? Is she a climate ‘denier’ or someone who has invoked the ire of the consensus police, or something? I went to Barnes’ web site, she is an Assistant Professor of Atmospheric Sciences at Colorado State University. I went through her web site pretty thoroughly owing to my Department Chair gene, I am always on the lookout for new faculty member talent. She looks like an excellent atmospheric dynamicist, and good atmospheric dynamicists are hard to find. Elizabeth is definitely a promising young scientist that I will keep my eye on.
So why on earth would Elizabeth Barnes be out to ‘get’ Jennifer Francis and discredit her work? Its very hard to imagine a reason, beyond the obligation of a scientist to challenge existing findings and push forward at the knowledge frontier.
JC message to Jennifer Francis: I’ve found that your credibility is reduced and your own motivations are questioned when you attack the motives of another scientist, particularly a young scientist without any apparent agenda beyond doing good science and advancing her academic career. The high ground is a much better place to be, and not just in a hurricane.
There has been no Arctic or Antarctic ice for 75% of the past 500 million years, the time during which multi-cell life thrived. And apparently the climate is more stable when there are no polar ice sheets.
So perhaps its just the transition to a more stable climate we should be addressing.
Climate may be more stable when there is no polar ice, but Climate is in our comfort zone when there is polar ice and temperatures are in the modern ten thousand year paradise.
Take your extreme stable period with no Polar Ice and put it where we will never see it.
I was going to crack a joke about how stability could also be described as “unprecendented” and thus bad, but somebody beat me to it.
Reblogged this on CraigM350.
I found Dr. Francis’ comments condescending. GRL is a top notch journal that has excellent editors and peer reviewers. Senior researchers should light the way for young scientists instead of attacking their motivations and reputations with unfounded accusations.
I think if one is getting in bed with Al Gore and trying to hype Sandy as due to global warming that their own motivated reasoning is quite evident.
Attacking someone else’s work in the way she did just confirms it.
From what Sandy is saying…
http://www.cbsnews.com/8301-201_162-57600023/farmers-almanac-predicts-a-bitterly-cold-winter/
it will be a very cold night as well.
The paper finds no evidence of an increased frequency of jet stream blocking or a decrease of jet stream speed, a result corroborated by a recent paper finding no significant changes of the jet stream over the past 140 years. The paper debunks claims by climate alarmists such as Heidi Cullen & Jennifer Francis that “Arctic amplification” is causing a “constipated jet stream” leading to increased extreme weather in North America.
http://hockeyschtick.blogspot.com/2013/08/new-paper-debunks-claims-that-arctic.html
The social psychologists who study this phenomenon of questioning motives behind non-consensus scientific papers are going to have a field in about 20 years. Is there no end to it? But it is repeated here by warmists every day so why should anyone be surprised.
As usual sea ice extent is now growing. The pace, however, has been freakishly brisk since Oct. 1st and amazing in scope. An Arctic refreeze record like this may portend exceptionally low winter temperatures, globally.
Some scientists foresee a global cooling trend in our future that could last for decades. If this will be the first winter of the next Ice Age what do the global warming alarmists of Western academia do then, give us our money back?
“JC message to Jennifer Francis: I’ve found that your credibility is reduced and your own motivations are questioned when you attack the motives of another scientist, particularly a young scientist without any apparent agenda beyond doing good science and advancing her academic career. The high ground is a much better place to be, and not just in a hurricane.”
How refreshing. A much needed spanking.
Bravo. Jennifer Francis also demolished her scientific credibility in her recent Congressional testimony with specious claims such as:
1. “Counter to claims by those who choose to ignore peer-reviewed scientific research, the heating of the Earth is not slowing down.”
2. Claiming Trenberth’s theory that the “missing heat” is going into the deep oceans is a proven fact
3. Claiming precipitation is increasing due to global warming using the only dataset showing so in NE US, while not mentioning there is no trend elsewhere in the US or on a global basis.
4. Claiming water vapor is increasing, while NVAP and radiosonde data over past 50 years show a decrease
5. Claiming warming increases tropical storms, while not mentioning many peer-reviewed papers & models show the opposite
6. Claiming warming decreases sea ice at both poles, while not mentioning Antarctic sea ice is at an all time high.
7. Claiming jet stream blocking has increased without mentioning contrary evidence.
http://www.epw.senate.gov/public/index.cfm?FuseAction=Files.View&FileStore_id=7bda72de-484b-418f-954f-c647de194569
Given all that, does Francis have any “scientific credibility”? Surely her peers will repudiate her as they did those exposed by Climategate? Oh, wait …
My gosh, Faustino, someone just makes a bunch of accusations and you accept them without question. Are you a skeptic or a sap?
“5. Claiming warming increases tropical storms”
I see a title: Warmer Oceans May Affect Tropical Storms
I’ve bolded two words which you’ve interpreted…weirdly.
This is why we call you climate deniers.
On the assertion that “the ‘missing heat’ is going into the deep oceans”.
I would like to find an analysis (or even a rough estimate) of the contribution of geothermal energy to the temperature of the deep ocean. For quick guesstimate, contribution from the Mid-Atlantic Ridge and East Pacific Rise (and the like) could be ignored, as could the cooling effect of descending ocean currents.
The temperature of deep mines (such as in South Africa) indicate a geothermal gradient exists; that energy has to go somewhere.
JC: DUPLICATE
Dagnabit.
Gonna repost with better formatting – just ’cause I know that PG would want me to…
Hmmmm.
Questioning motives should never be a part of the debate, IMO. I agree that it diminishes credibility – at least unless someone has actual evidence about motives.
That said….
Really, Judith? Given the comments you see daily on this blog, and further, given the thoughts that you write on a regular basis in your posts, you pick those comments to illustrate how it diminishes credibility when someone suggests that a scientist has been less than objective and should take a more balanced approach?
Selective reasoning is selective.
BTW – just to make sure that PG doesn’t get upset, I will add that you seem like a very nice person who is tackling the important issue of quantifying uncertainty, Judith – and you run a good blog.
Joshua:
Perhaps Jennifer Francis could have been a bit more indirect with her points.
Ragnaar –
Could have been and should have been. Judith is right that it diminishes Francis’ credibility, and Chris is right that Barnes has a right to publish her research w/o having her motives questioned.
But those conditions should apply across the board. No one should have their motives questioned, and questioning motivations diminishes the credibility of the questioner (unless they have evidence that directly speaks to motives.
I think that there is some question as to whether saying that someone is less than objective and should be more balanced is the same as questioning their motives – but it is close enough for Jazz.
But if Judith is going to hold Francis to that standard, then she would have to basically change her own entire approach to the debate to prove even-handed. Actually, I think that would be a good thing. It might help with building bridges.
Joshua said in his post on August 21, 2013 at 10:35 pm
“Really, Judith? Given the comments you see daily on this blog, and further, given the thoughts that you write on a regular basis in your posts, you pick those comments to illustrate how it diminishes credibility when someone suggests that a scientist has been less than objective and should take a more balanced approach?”
______
Good point. If it diminishes a person’s credibility to question a scientist’s motivation and objectivity, most of the people who post here have little if any credibility.
Josh,
you are past tedious and into first class ass territory.
Unless you are operating under motivated reasoning influences, it is almost impossible to see Dr Francis’s comments as either ad hominum or condescending.
To use a couple of phrases/terms from younger generations – “get a grip dude”.
Your grip on being able to have an informed, rational discussion is hanging by the fingernails.
Tim –
You’ve been writing virtually the exact same comments to me for months now (when you haven’t been pumping those pom-poms).
Now you seem like a smart person – so what do you think? Based on what has already transpired, do you think that I give any credibility to those comments of yours?
Josh passed tedious a long time ago. His “comments” are generally so vapidly wearying that they could well be utilized for the purposes of medically induced coma.
Oops, thats pokerguy.
PG – all I care about is that they get you to shower.
You know, when you read them “accidentally.”
Maybe timg56 was just following Judith’s example. Francis criticized Barnes, which diminished Francis, then Judith criticized Francis for criticizing Barnes, which in turn diminished Judith.
Josh,
if I have been doing so for months, that is indication of how long you have drifted into irrelativeness.
As to what I think, I think your comment at 10:55 is of the sort that makes you a credible commenter. At least up to the point where you can’t resist taking a shot at Curry.
i also think that your tribalism arguments are extremely filtered. If it wasn’t for Max OK’s age argument, yours would be one of the poorest put forth here. Dr Curry makes a good case for that point, yet because it doesn’t fit with your believe system, you feel you have to find fault.
Please tell me how you think Dr Francis’s remarks in response to reporting on the Barnes paper are not only reasonable, within the pale, what should be expected from one researcher to another and not in the least bit tribal.
In other words Josh, show some fucking integrity.
PS – I have never been that impressed by Chris Colose’s arguments on the science, but at least I’ve credited him for engaging and think his comment below shows greatly to his credit. You would do well to consider it as an example.
Joshua:
“What perplexes me, however, is that her intent in interpreting the new results in Barnes (2013) seems less than objective and is a direct attempt to disprove the work presented in Francis and Vavrus (2012; hereafter FV12). A very different interpretation of the results could be made…” – Dr. Francis.
Rewriting this in a softer way I come up with:
I have looked over the Barnes (2013) paper and raise the question of, could the results be interpreted another way? I hope that with both papers, the standard of objectivity is being followed.
Dr. Francis has I suppose already has seen a bit of bounceback from her comments, which is unfortunate. It could have turned out better for both sides I think. And of course I’ve made too many mistakes to even remember half of them.
Nice post, Ragnaar –
Although how it turns out could take an unexpected turn. Perhaps as a result of the bounceback, Francis will be more careful in the future to avoid drawing conclusions w/o evidence? It seems that is Judith’s conceptualization? Might be unlikely, but it is possible.
On the other hand, Francis may just become more entrenched, with more of a justification for a sense of victimhood. That does seem to be the pattern in the climate wars. Which is why posts like this puzzle me from Judith, as it seems that the pattern is fairly well established. You know, doing the same things and expecting different results, and all. Not very conducive to bridge-building, IMO.
Joshua
“What perplexes me, however, is that her intent in interpreting the new results in Barnes (2013) seems less than objective and is a direct attempt to disprove the work presented in Francis and Vavrus (2012; hereafter FV12). ”
1. how does francis know what the intent is
2. How is a direct attempt to disprove something less than objective?
This gets back to the silly notion that you should not disprove somebodies work, but rather journals demand that you find something new. Trust me I’ve seen this silly attitude on more than one occassion.
Next if Francis wants to respond she can do what we tell skeptics to do.
publish your response through normal channels
MORE Motive hunting
“The stratosphere is cooling with increasing greenhouse gases, leading to very different dynamical changes. Why did she choose to analyze this level? My only guess is to deliberately cast doubt on FV12.
I don’t know, steven. Unless Francis has some direct evidence (which I doubt) she couldn’t know intent. That’s why I said close enough for Jazz – (in the building trades, we used to say close-enough for government work, but there are too many libertarians about for me to want to use that kind of language).
As such, her statement would be an example of motivated reasoning and a scientist not employing a scientific approach to analysis – a smart person attributing causality (intent) when they don’t have evidence of such. It is ubiquitous in the climate wars. You see it in comment after comment in these pages. It’s easy to see even for those who aren’t terribly bright, like me.
.
How do you know what anyone was attempting to do? Your last paragraph is missing an endquote and attribution – making it kind of hard for me to parse.
At any rate, w/o rock solid direct evidence, I tend to assume that scientists are attempting to analyze the data, not prove or disprove something. But at any rate, attempting to disprove something is not mutually exclusive with subjectivity – so I don’t get your logic.
You see it in everyone but urself. Enough with ur mommy mommy crap.
Josh the last quote is from francis. Read harder
Steve,
I respect that you are consistent in taking apart an argument. People seem to lose that part of integrity all too often.
Good answer by the way on your follow up. I had not thought (did not know enough) to consider that perspective in sensitivity.
Agreed with this. Arctic sea ice and mid-lat relationships is complex and the Francis arguments have provided fodder as a good hypothesis for further testing, but the jury is still out. Barnes has every right to add to the discussion without her motives questioned.
+1
Chris,
Coming to the support of fellow scientists, whether or not you agree with their conclusions, is something to be recognized and acknowledged.
Good on you.
Well done, Chris.
The Jennifer Francis comments are nasty, over-the-top, and inappropriate for scientific discourse. They are strangely reminiscent of the politicized style of Michael Mann and his cohorts.
For a curious sidelight, I noticed that the younger scientist Elizabeth Barnes, who is being accused of somehow lacking objectivity and balance, was lead author on a 2012 methodology paper in which the UK Met Office’s chief scientist Julia Slingo featured as a co-author! The paper is paywalled, but from the abstract it seems to pay some obeisance to “global warming” worries….. so it turns out to be extremely bizarre that Elizabeth Barnes is being attacked by Jennifer Francis as though beyond the pale and outside the tribe of loyal climatologists.
Barnes, Elizabeth A., Julia Slingo and Tim Woollings, 2012: A methodology for the comparison of blocking climatologies across indices, models and climate scenarios.^^ Climate Dynamics, 38, 2467-2481, doi:10.1007/s00382-011-1243-6.
“The Jennifer Francis comments are nasty, over-the-top, and inappropriate for scientific discourse. They are strangely reminiscent of the politicized style of Michael Mann and his cohorts.”
I wouldnt call them over the top. maybe shes a bit testy.
mann attributed evil motives. Francis attributed good motives
” good grief, she wants to prove me wrong”
Well you know all this stuff far better than I do, but the reason I see Francis as way out of line is because Barnes published a peer-reviewed scientific article, and rather than submit a journal comment (which she may still do of course), Francis accuses Barnes (with no evidence) of acting from personal bias.
For the number of times we have all heard that proper ClimateScience-TM is only properly conducted in refereed journals, it is quite disappointing to see a senior figure trying to discredit a young scientist with this public (unsubstantiated) accusation of bias. In many tenure processes, this kind of lingering accusation could certainly affect someone’s professional prospects, not to mention possibilities for recruitment by other universities. Francis makes a scientific dispute quite personal and vindictive, imho.
“For the number of times we have all heard that proper ClimateScience-TM is only properly conducted in refereed journals, it is quite disappointing to see a senior figure trying to discredit a young scientist with this public (unsubstantiated) accusation of bias.”
Disappointing? I thought this is what climate skeptics wanted. Climate skeptics haven’t been shy to attack scientists and smear them online.
I don’t think you can act concerned or disappointed when a scientist does it to another scientist.
Speaking of attributing evil motives, now Michael Mann (on Twitter) is accusing Judith Curry of “purveying distraction and confusion” (I actually heard the Harris piece with Judith Curry on NPR today, and thought it was decent although certainly not an uncritical “puff” piece — it did portray our hostess as on the outs with a lot of the CliSci world) —
=====================================================
Michael E. Mann @MichaelEMann
Pathetic #RichardHarris @NPR puffpiece glorifies #JudyCurry for purveying #climatechange distraction & confusion http://fb.me/1mzJ62jBi
lolwot, I can ask and demand that ppl adhere to their own professed standards. Since numerous ClimateScience-TM adherents tell us that personal attacks on blogs are inappropriate for scientific discussions, when I see a prominent climate scientist making unprovoked personal attacks I can certainly point it out.
“Since numerous ClimateScience-TM adherents tell us that personal attacks on blogs are inappropriate for scientific discussions”
No-one has told you that.
Personal attacks have nothing to do with scientific discussions. Blogs are just the right kind of place for personal attacks.
I don’t see *language* as intemperate as is suggested, but the undercurrents are still there. Perhaps, Francis would like to reword her response? I mean, the transition from something about waves and amplitudes to motivations doesn’t make any sense.
I do agree, however, that once your line is presented to Congress on matters of climate, it is easy, thanks to people like Joshua, to cast scientific challenge to your theory as political/motivated objections and deal with them that way. It kills two birds with one stone.
Thank you, Professor Curry, for your excellent blog on climate science.
If the simultaneous loss of integrity in science and constitutional government is no mere coincidence – as some of us believe – then the Electronic Frontier Foundation has some good news (via tallbloke)
http://tallbloke.wordpress.com/2013/08/22/eff-victory-results-in-release-of-secret-court-opinion-finding-nsa-surveillance-unconstitutional/
And to top it, the whole thing ice-melt=’extreme’ weather is post-hoc bulls*** reasoning in the first place.
I think when someone negates the conclusion of your paper as just an “artifact of the methodology” that looks like a serious attack, and it needs some serious backing up. Francis obviously did not see that the strong wording was merited, and pointed out some reasons that the criticism is not that black and white and some choices made in the paper that looked like motivated reasoning, to coin a term.
It is also noteworthy that Barnes did find support for Francis’s idea in October to December (OND), which are precisely the periods that Britain had exceptional snow in recent years. In her abstract Barnes said the Francis results “are” an artifact, not “could be”, or even “seem to be”. Words are important because exception could be taken. This paper could easily have highlighted that positive support for OND, but chose a different route.
Jim D:
“In her abstract Barnes said the Francis results “are” an artifact, not “could be”, or even “seem to be”.”
As hesitant as I am admit this, I see your point.
And we could blame the reviewers for not picking up on such a strong statement without strong support, unless it was added in a late revision. Things like this get through.
JimD said;
“Britain had ‘exceptional snow.’
Citation please. What do you mean by ‘exceptional’ and which ‘recent’ years are you talking about? Thanks
tonyb
tonyb, Decembers 2009 and 2010 were exceptional in the UK from what I heard. Maybe another one since then. I don’t live there, but you do, I thought.
JImD
I do live in Britain which is precisely why I picked you up on your comment. You said;
‘It is also noteworthy that Barnes did find support for Francis’s idea in October to December (OND)”
Now you are merely referring to just two Decembers. A couple of months out of many, spread over ‘recent years’ hardly makes any sort of case either way does it?
tonyb
it is also noteworthy that Barnes did find support for Francis’s idea in October to December (OND)”
OND is when the stratosphere allows the arctic vortice to form o3 decreases by around 20-30%
2009 was at the trough of solar minima so o3 production would be at its least, 2010,and 2011 there was significant O3 decreases due to the Iceland volcanos and the invariable transition to a positive arctic oscillation.
The set of coincidences being consistent of what was seen in 1784 (Laki)
maybe Francis does not understand chance.
Maksimovitch
We can provide evidence for the real world effects of Laki. This is an extract from the archives of Exeter Cathedral
‘1783 ‘Extra poor relief in extreme cold’
Tonyb
Thordarson, and Self 2003 exceptional paper on this covers good references to both meteorological data and manuscript as well as synoptic weather maps of the westerly jet.
http://adsabs.harvard.edu/abs/2003JGRD..108.4011T
I find that the Overland/Francis paper and Barnes one were looking at North America, so while the basic idea is similar to previous Met Office explanations about those British winters, it was not quite relevant to bring it up. Britain is in a prime spot at the west of a large continent to feel any such easterly anomalies that may occur through weakened zonal flows. I am sure people have studied this in the context of sea-ice cover, or, if not, they should. Perhaps the record is not long enough yet, because the sea-ice decline only became faster in the past decade during which Britain had two exceptional winters. It may need a decade or more of these events to prove anything regarding climate change.
We quantify observed trends in the meridional extent of waves over the North Atlantic/North America region using two different metrics and three re
analyses. We find that the metrics disagree on whether a significant trend in wave extent has been observed, and we explain this disagreement as arising due to the methodology of defining the wave on either daily or seasonal time-scales. In addition, we demonstrate that metrics that focus on a narrow range of isopleths to track the ridges and troughs of a passing wave will incorrectly interpret a shift of the geopotential height field as a change in wave extent. When this shift is accounted for, no significant trend is found. We further investigate whether large-scale waves have slowed down in the recent decades and find no significant trends except in the Autumn months, although the significance of this trend is sensitive to the diagnostic field and the specific averaging domain. Furthermore, no significant increase in blocking occurrence is detected in any season. We conclude that the mechanism put forth by previous studies (e.g. Francis and Vavrus [2012]; Liu et al. [2012]), that amplified polar warming has lead to the increased occurrence of slow-moving weather patterns and blocking episodes, is unsupported by the observations.’
Don’t need to read the paper – just the abstract? Usually – and as well – you need to read one or two others papers at least to put things into a sensible context.
I should not respond to a multiple sockpuppet offender such as the Chief, but he did quote from the abstract which mentions the issue of the geopotential height change with global warming.
As it happens, my most recent in-depth blog post analyzes the change in geopotential height over the past 65 years. The change is significant and it appears to have a subtle lapse rate change component.
http://theoilconundrum.blogspot.com
See latest post on “Expansion of Atmosphere and Ocean” and scroll to the bottom for lapse rate calculation updates.
I would like to see more data and analysis on the topic of geopotential height changes, and I think that is what Barnes is providing.
I first of all quoted from the conclusions. The geopotential height is the height of a pressure surface with the atmosphere. It changes with temperature. Elizabeth Barnes incorporates changes in geopotential height to analyse for changes in storm tracks.
‘ In addition, we demonstrate that metrics that focus on a narrow range of isopleths to track the ridges and troughs of a passing wave will incorrectly interpret a shift of the geopotential height field as a change in wave extent. When this shift is accounted for, no significant trend is found.’
The lack of trend in storm tracks is the important point and not a value that is acknowledged to change.
Webby’s geopotential height and dry adiabatic lapse (not the actual environmental lapse) rate are conceptual properties based on incorrect physics and gross approximations. They are climate trivia that can be calculated using simple formula by an 8 year old.
e.g. http://www.aerostudents.com/files/aerodynamicsA/relationsPressureHeight.pdf
http://www.shodor.org/os411/courses/_master/tools/calculators/lapserate/
Here is some actual and meaningful data in the real world that webby doesn’t seem to inhabit.
http://iridl.ldeo.columbia.edu/maproom/Global/Atm_Circulation/Monthly_Height_500hPa.html
The geopotential height is the height of a pressure surface with the atmosphere. It changes with temperature. Elizabeth Barnes incorporates changes in geopotential height to analyse for changes in storm tracks.
Fioletov, 2008 shows there is a strong correlation with total column O3 and weather conditions such as t and the resulting location of pressure lows and highs.Tropospheric height can vary fast (Hours) in response to column O3 changes( up to 5 km).
Snap to it Chief.
I wouldn’t normally expect a multiple sockpuppet abuser like the Chief to actually do anything useful, but might as well suggest that he give that dataset he linked to a deeper analysis.
I bet that will never happen, as Chief said you have to be as smart as an 8-year old.
That essentially excludes The Chief hisself.
.
Climate trivia and blog abuse are twin webster specialities. The simple formulas for geopotential and dry adiabatic lapse rate are not terribly useful in the real world.
The database linked to shows real world variability in contrast to simple formula and gross assumptions. The point was to contrast the real world to delusionally simple minded self aggrandisement.
It all gets a bit tedious.
I should probably not respond to a multiple sockpuppet offender like the Chief Hydrologist, but he really needs to be shamed more often.
The analysis that I did here http://theoilconundrum.blogspot.com/2013/07/expansion-of-atmosphere-and-ocean.html is actually quite sophisticated. The point of looking at the increased geopotential height over time is to evaluate the global warming signal from a different perspective than is usually done.
The likelihood is that the lapse rate has changed slightly due to the increased warming, as the atmosphere has the potential to hold more water.
Notice how a low-life internet scum such as the Chief Hydrologist has nothing better to do than to adopt multiple sockpuppet identities and lash out in anger at other commenters. He does this while not lifting a finger in doing a detailed analysis, assuming that people reading his stuff think that arbitrarily copying & pasting links substitutes for deep thinking.
Webster, the atmosphere has changed over time. What little quality atmospheric data we have agrees well with the little OHC data we have. The Stratosphere data tracks the oceans quite well. But 0.8 C per ~316 years is not something that can be attributed to CO2 forcing “mainly” without a significant Tropical Troposphere hot spot. As Maks said, sensitivity to O3 has increased, that can be a negative feedback. Water vapor response is not following the CO2 forcing game plan, an indication of greater than expect natural variability.
All of these little hints that things don’t respond the same at different energy levels. What do you make of that?
Cappy, You speaketh gibberish.
Ask the UN.
http://www.weeklystandard.com/blogs/state-department-refers-questions-about-ambassador-power-un_750073.html
The difference between webby and myself is that is that I actually discuss science with quotes, links and everything. Must be hundreds of papers – more all the time. Several more in the past couple of days. I have always – well since the age of three – been a speed reader. I am trained in engineering with a hydrology background – an intensive experience in itself – and in environmental science. I have an advantage in studying the source of global rainfall regimes starting with a single paper by 2 Australian geomorphologists in 1988.
Here I was discussing the paper itself and webby jumps to his usual simplistic ideas – this time about geopotential heights. The formula is very simple and the concept simpler. I linked to a site earlier. He calls this heavy lifting – sophisticated analysis – but it is nothing more than one line of mathematics representing a single and simple concept. It is bizarre that he makes so much of this. It means nothing – it is climate trivia with which he wastes everyone’s time.
Webby is an electrical engineer who insists that the oceans are a CPU heat sink – and other such conceptually incorrect climate trivialities – when he references ‘science’ it is his delusional blog science in a quite silly and self aggrandising manner. For the most part he is simply abusive and obnoxious. It seems tied up with his sense of self worth somehow. I suspect it is a space cadet habit of assumed intellectual and moral superiority classically symptomatic of groupthink. It seems destined to crash and burn.
Many commenters here have an extremely limited understanding of quite basic aspects of climate science. There are things that would be better learned before venturing an opinion. I have used Dr Dunderhead in the past couple of days in some gentle and polite didactic sense. The clear sense is that I am not entering a discourse but espousing some basic concepts that they need to make even the most elemental sense of climate science. I do not change my email address so it should be fairly clear to Judith who I am. I don’t think that I am fooling anyone – that’s part of the joke. Although webby does seem to lack a sense of humour as well. I may continue in the didactic manner when warranted.
Captain Kangaroo was a climate warrior on a blue horse called Shibboleth. He was promoted to Generalissimo Skippy and retired after the “Great Northern Rivers Frog Battle of 2012′. His identity is a secret of the climate war known only to a cowgirl on a damn camel.
It is a shame that the site has degenerated to carping and smarmy snarks with little content, less civility and no sense of fun and creativity. The eSalon is looking decidedly faded. Seriously – if this were Big Brother we could vote webby off. Failing that – I’d suggest adding the words ‘peak oil’ to the moderated list.
The camel went feral Chief, think the cg maybe did too. (
Bts
The Chief Hydrologist is a multiple sockpuppet abuser who has gone by the deceptive names of Captain Kangaroo, Generalissimo Skippy, Dr. Dunderhead, and who knows how many others.
Sockpuppets are the low-life scum of the internet as they adopt aliases as a means to deceive and create fake grassroots enthusiasm for their usually krackpot ideas.
To top it off, The Chief jumps the shark with his self-aggrandizement and delusions of grandeur. He has no peer-reviewed citations to speak of so blathers on and on.
I disagree, Jim D. If the results are in fact an artifact of the methodology, how else to say so, and why not say it? It doesn’t say anything about the motives of the person using the methodology; anyone can make an honest mistake, and that may have been what it was.
I’m reminded of Andrew Wiles’ first attempt at proving Fermat’s last conjecture. After presenting his work at a conference, he wrote up his proof and it was refereed. One of the referees picked up a mistake, which meant Wiles had to go back to the drawing board and correct it, which took quite some time. But he accepted that his initial proof was an artifact of his erroneous methodology.
Did that mean his reviewer had made a “serious attack”? Did it mean that Wiles was some kind of scoundrel or incompetent? Should the reviewer not have pointed out the error and described it in detail for what it factually was?
Honestly, this kind of attitude is exactly why people have so little confidence in, and respect for, climate scientists. What’s wrong with directly addressing a possible error in methodology? Why is that framed in terms of being a “direct attack” and “less than objective? To me, it just seems like normal science. If Dr. Francis thinks Dr. Barnes’ critique is incorrect, then she should simply show why there is no error in her methodology. And if she can’t, then she needs to go back to the drawing board just as Andrew Wiles did.
If you don’t want a field to degenerate into a dumpful of garbage results, some degree of basic methods policing is essential. In management, there used to be a literature on “strategic groups” that clustered firms by maximizing the within-v.-between F-statistic and then “tested” for “significance” of the clusters using the same F-statistic. Oops. The Boston Consulting Group for years successfully pushed their “growth-share” matrix for classifying the business units of diversified firms; one critique that mostly killed it off among academics was that trivial changes in market definition would completely alter the classification.
You’ve got to kill off the stuff that’s fundamentally wrong even if it embarrasses people, not restrict yourself to arguing over the debatable fine points. Natural sciences are thought to be better at this than social sciences, probably with good reason. It would be perverse to establish a norm of not loudly calling BS on invalid methods.
Wiles didn’t make a mistake. He use a piece of math that was a conjecture, empirically derived, but that there was no existing proof. So after the first paper he had to return to the conjecture and derive a proof, which he did with the aid of two other mathematicians.
So mistake is a little harsh.
Jennifer Francis’ comments are the purring of a a pussy cat.
Did you know that “the leading scientists” now think that ” every extreme weather event now has a component of global warming in it?” And that deniers are like racist, slave owning, homophobes, financed by the Koch brothers and Exxon-Mobile?
You know it’s so, because Al Gore says so.
http://www.washingtonpost.com/blogs/wonkblog/wp/2013/08/21/al-gore-explains-why-hes-optimistic-about-stopping-global-warming/
We skeptics are blessed by the nature of our opponents.
“And that deniers are like racist, slave owning, homophobes, financed by the Koch brothers and Exxon-Mobile?”
______
I doubt many are financed by Exxon-Mobile.
Jennifer Francis writes:
“So why on earth would Elizabeth Barnes be out to ‘get’ Jennifer Francis and discredit her work? Its very hard to imagine a reason, beyond the obligation of a scientist to challenge existing findings and push forward at the knowledge frontier.”
Well, gosh, Jennifer, the obligation of a scientist to challenge existing findings necessarily leads to the discrediting of the work that produced the existing findings when that work produced false claims about data, misrepresented data, produced incorrect inferences from hypotheses or theories or contained any number of other problems that made the work discreditable. Check Elizabeth’s work and see what she said you did wrong. Then you will know why she discredited your paper.
Theo, I think she did some checking on Barnes’ work. Didn’t you read Jason Samenow’s article. JC gave a link to it.
“Jennifer Francis writes:
So why on earth would Elizabeth Barnes be out to ‘get’ Jennifer Francis and discredit her work? Its very hard to imagine a reason, beyond the obligation of a scientist to challenge existing findings and push forward at the knowledge frontier.” ”
I don’t know where you found this quote, Theo, but I assure you that I never said it. JAF
What is needed is a proper study evaluating the pressure pattern changes that occur during atmospheric changes experienced during low solar cycles.
This is the real driver behind the jet stream changes that continue to create havoc and will continue to do so for decades if my solar predictions pan out.
The upcoming NH winter will still experience unusual jet stream activity despite a return to more “normal” Arctic sea ice extent.
Correct.
http://www.newclimatemodel.com/new-climate-model/
” But a new study finds little evidence to support the idea that the plummeting Arctic sea ice has meaningfully changed our weather patterns”
It will affect. When ice disappears on arctic – winters in USA, Europe become much colder – than equalizes.
warmth doesn’t melt the ice in arctic, but, the salty water currents from below – when currents speed up -> more ice is melted
There has been very little examination of the satellite data from Nimbus 1, II, and III, which would provide an excellent example of atmospheric dynamics in the mid to late 1960’s, including two hurricane seasons. As far as I know not one scientist beyond the National Snow and Ice Data Center’s work on ice pack data, which has some interesting results….
As Hockey Schtick linked to:
“As the oceans continue to absorb additional heat trapped by ever-accumulating greenhouse gases (1), as sea ice continues to disappear (1), and as the Arctic continues to warm faster than the rest of the globe (1), we can only expect to see more weather-related adverse impacts (2). The details of those impacts are still emerging from ongoing research (2), but the overall picture of the future is clear (1).” – J. Francis – Senate Hearing – 7/18/13. Conclusions.
(1) Stated as fact
(2) Qualified – that is, less than certain.
My point is not the accuracy of anything she said above. It is the confidence she had in this paragraph. I do like her style: 1, 1, 1, 2, 2, 1. The 2s are buried, placed where their position de-emphasizes them. Strong start, strong conclusion.
It seems Dr. Francis in that one paragraph, a tiny part of all the work she’s done, was driving with her foot on the gas. This sure is a complicated deal.
Ragnarr,
Dr. Francis is confident.
Dr. Barnes is confident. As you said: “In her abstract Barnes said the Francis results “are” an artifact, not “could be”, or even “seem to be”.”
No uncertainty among these two. JC should be appalled.
Max_OK writes:
“Dr. Francis is confident.
Dr. Barnes is confident.”
Which I think might true in this case, but overall I don’t know. A lot of Science is done without so bright a spotlight on it and in this case, two Scientists that were previously unknown to me are front and center. There’s the additional pressure of large audiences on them and what I think is called the tribalism. Where each new paper is breaking for news for us. I see I jumped into this topic without a good understanding of it, because of my bias. I’ve a ways to go. I am sorry I criticized Dr. Francis, and thank both the Scientists for their work.
plummeting? Oh ignoring climatic history.
JC wrote:
“In yet another post by Jason Samenow, entitled Researcher defends linking Arctic warming and extreme weather, Jennifer Francis responds to Barnes’ paper.”
_____
JC, you didn’t mention that Jason Samenow asked Jennifer Francis’ for her thoughts on the Barnes’ paper. In the comments section of his article he says this:
“In fairness, I asked Dr. Francis for her thoughts on the paper, and she sent them to me. Of course, she can also submit a more formal comment to the journal so this debate gets aired through academic channels.”
The dog ate my global warming.
OK, that’s apparently the only excuse the IPCC is not going to use to explain the “pause” in the AR5.
“The IPCC report attributes this hiatus to short-term factors that result in temporary cooling periods, including volcanoes, solar cycles, absorbent oceans, non-greenhouse-gas pollutants, and a string of other temporary-yet-powerful natural forces.”
http://www.nationaljournal.com/energy/separating-science-from-spin-on-the-global-warming-pause-20130821
Well, GaryM, some people might think a pause is short term.
Max_OK
Yep.
But it looks like it’s getting longer day-by-day.
Max_CH
Of course we have to remember the warming trend since 2009 is running at about 0.24C/decade. The warming trend up to 2009 was 0.16C/decade.
http://www.woodfortrees.org/plot/uah/plot/uah/from:1979/to:2008/trend/plot/uah/from:2008/trend
“Of course we have to remember the warming trend since 2009 is running at about 0.24C/decade. The warming trend up to 2009 was 0.16C/decade.”
Are you sure it wasn’t 0.24321 and 0.15962?
What is it with these alarmist prima donnas who seem to think that it is their Gaia-given right to have their published work accepted without question?!
Why are they still dancing as though the world scientific stage has not advanced since 2009?
And when will they realize that conjuring up adverse “motives” on the part of their critics – as a way of avoiding dealing with the reality of the <<gasp>> content – simply does not wash any more? Not for Mann and his coterie, and not for Francis.
Well, IMHO, it never really did, but they always seemed to get away with such self-serving nonsense … back in the halcyon days when mediocrity still ruled, and nothing ever seemed to matter – as long as it was in line with the message of the month for “the cause”!
Where did Francis say she had a right to have her published work accepted without question?
Are you questioning her right to comment on Barnes’ work about her work?
“Are you questioning her right to comment on Barnes’ work about her work?”
strange. you know a while back when Nic Lewis publically critcized Fosters work, here at climate audit several folks ( like FOMD, josh, willard kinda sorta ) got their panties in a knot for Nic violating good science manners.
Where were you to defend Nic?
ah yes, no where to be found
Steve, you may not know I go for days even weeks without looking at Climate Etc. I don’t recall readers accusing Nic Lewis’ of violating science manners, so I don’t know whether I would have defended him.
Really max .. suggest u reread yourself
Steven, I don’t remember the discussion about Nic Lewis’ science manners. Do you have evidence I participated in the discussion or was aware of it?
‘Prediction of weather and climate are necessarily uncertain: our observations of weather and climate are uncertain, the models into which we assimilate this data and predict the future are uncertain, and external effects such as volcanoes and anthropogenic greenhouse emissions are also uncertain. Fundamentally, therefore, therefore we should think of weather and climate predictions in terms of equations whose basic prognostic variables are probability densities ρ(X,t) where X denotes some climatic variable and t denoted time. In this way, ρ(X,t)dV represents the probability that, at time t, the true value of X lies in some small volume dV of state space.’ (Predicting Weather and Climate – Palmer and Hagedorn eds – 2006)
Some people have the odd idea that uncertainty means that no comment can be at all definitive and every, small thing should be garnished with qualifications.
Certainly with climate data is incomplete – whole realms of unknown or poorly known mechanisms – and limited in either temporal or spatial coverage. (One of the essential problem of these types of studies is the small time periods covered by data. A blink in timescales of planetary variability.) The models are intrinsically uncertain because they are inherently chaotic. Emissions are uncertain because it depends on so many factors.
‘We conclude that the mechanism put forth by previous studies (e.g. Francis and Vavrus [2012]; Liu et al. [2012]), that amplified polar warming has lead to the increased occurrence of slow-moving weather patterns and blocking episodes, is unsupported by the observations.’
Seems not all that uncertain. Prove that it’s wrong.
Prove it’s wrong?
You must have lost your science cap.
Australia, the West Virginia of Asia. HA HA !
Science cap? West Virginia? Why don’t you try for the record for idiot non sequiturs. I have faith in you.
http://nsidc.org/arcticseaicenews/
Global sea ice extent is 5.94 + 18.70 = 24.64 msk or around 4% below the 1979-2000 average baseline for this date.
Max
Comments back on on this thread?
Yes, seems like a comment from Fan nuked the thread.
It’s that junk he puts at the end. Using that sort of stuff requires testing, and should only be done with
a goodan extremely good reason. Stupid smiley faces aren’t a good reason, and it’s obvious he doesn’t understand how the HTML he’s sending actually works.For the record, if you want to test your comment on Windoz, you can copy the stuff from the comment window into a local HTML file you’re editing with notepad, fire it up in a browser, and see the results. For simple stuff like blockquote tags, bold, italics, etc. that works fine.
The posting software strips out paragraph tags, and translates a double return into a paragraph tag, so if you want your comment to work both in the blog and your test environment, you need to start each paragraph with two returns and a paragraph tag.
I use a fairly quick process:
– ctrl-a to highlight everything in the comment window,
– ctrl-c to copy it to the clipboard,
– click the mouse on the notepad window (assuming it’s already up),
– ctrl-a to highlight all the old stuff in the window,
– ctrl-v to copy the stuff from the clipboard to the notepad window (which deletes everything already highlighted),
– ctrl-s to save the test file,
– click the mouse on the browser tab containing the test file,
– and click the refresh button in the browser.
Takes about 2 seconds for a single test cycle, which means I can edit and test until the comment looks good.
I like Fan’s crayon box and various and sundry doohickey’s. As soon as I see them I know I don’t need to read a word. They are real time savers. He should just put them at the beginning of his comments. Like those bio hazard signs they have for medical waste containers in hospitals. “This comment contains material that could be hazardous to your IQ.”
Imagine that. Fanny’s injecting ill-behaved content. Sounds like “professional grade hacking” to me (which is what he was accusing Watts of doing).
Harold, to be fair, I think he only accused me of hacking. I don’t think anyone claims following the links I shared was hacking. I could be wrong though.
I received this email from a recent PhD alum from Georgia Tech, makes all this worthwhile.
——
Judy –
Hope all is well with you, Peter, and everyone else in EAS.
I just wanted to send you an e-mail and ‘thank you’ for your recent blog
post on Jennifer Francis and her unfortunate response to Elizabeth
Barnes (http://judithcurry.com/2013/08/21/arctic-sea-ice-and-weather/).
When I read the article yesterday and Francis’s remarks, I was taken
aback. The science is grounded in having scientists conduct analyses,
offer hypotheses, and have those hypotheses tested. Opposing points of
view are likely to emerge (and should!), but to impugn another
scientist’s motives and scientific integrity is stepping over the line.
Again, thank you for blogging about this.
Judith, I’m sure such comments are deeply gratifying.
I’ve come to admire your forbearance greatly. At the same time, my sense is you’ve become a little more willing to speak your mind, as in your response to J.F. I don’t think you’d have done such a thing a year ago, though of course I could be wrong about that. I’m also liking that you seem lately to be more willing to engage “on blog.” At least on this thread. It makes for a livelier proceeding imvho.
As arctic sea ice is increasingly melting in summers (providing new maritime shipping routes) and as, at the same time, antarctic winter temperatures seem to become much lower than usual … all the above observations suggested me the hypothesis that there must exist some kind of heat transport mechanism between south towards northern hemispheres. Is my theory speculative?: Yes, but if Al Gore and a Panel of scientist support my idea, all the world would end up believing in it.
“As arctic sea ice is increasingly melting in summers”
If we are losing ice in the Northern Hemisphere, at an increasing rate, then we should be able to observe this in the sea level.
I had a look at the UC seasonal adjusted dataset and plotted the rate.
I can see on evidence for an ‘increasing’ rate of sea level rise, which means that landlocked ice isn’t melting at an increased rate and that the oceans have not heated at an accelerated rate.
http://i179.photobucket.com/albums/w318/DocMartyn/SatalliteSeaLevelandrateofchange_zpsc3f847e9.png
Antonio, you write “there must exist some kind of heat transport mechanism between south towards northern hemispheres”
Not necessarily. There could be a global phemenon, such as a change in cloud cover, which causes the Arctic to get warm, and the Antarctic to get cold.
Obviously, radiative physics fails miserably in the Southern hemisphere.
The global sea ice anomaly is a big, fat goose egg.
Nesting unicorns prevent warming and we all know they are a migratory species that give birth in the Polar regions of the Southern Hemisphere.
Francis’ critique: “What perplexes me, however, is that her intent in interpreting the new results in Barnes (2013) seems less than objective and is a direct attempt to disprove the work presented in Francis and Vavrus (2012; hereafter FV12).
…
These new results provide additional insight into those linkages, but it appears that the interpretation of these results in Barnes (2013) was conducted with a particular intent.”
Her choice of words is confusing. Her intent is less than objective? Subjective and objective intent are distinctions with a difference in criminal law, and contract law. But those distinctions make no sense as used by Francis.
If this is an attempt to suggest improper motivation, or “big-oil funding” type bias, it is a pretty sloppy way to do so. It seems to me, if you are going to question someone’s integrity, you should not not only present some evidence, but maybe at least have the decency to say exactly what the hell you mean?
A couple of comments. I think it ironic that this discussion is takng place when the trend towards lower Arctic sea ice extent seems to have been broken. A quote from the mid-August NSIDC report http://nsidc.org/arcticseaicenews/
“Projections of the likely minimum extent this year based on retreat rates from past years argue that it is highly unlikely that sea ice will surpass the record-setting low extent seen in 2012. With retreat rates similar to those of 2007 to 2012, the minimum extent would be near 5.0 million square kilometers (2.0 million square miles) in mid-September.”
It seems to me that Prof. Francis’s actions indicate that the warmists are getting desperate. The IPCC AR5 report also seems to be in very serious trouble. When one relies on expert opinion, instead of empirical data, life becomes difficult when the empirical data challenges the expert opinion; c.f Richard Feynman.
Come off it, you guys thought the trend towards lower arctic sea ice had been broken in 2008.
When you going to learn that a single year does not make or break a trend.
” Jennifer Francis and her unfortunate response to Elizabeth Barnes”
_____
Well, it wasn’t exactly a response to Barnes. It was Francis’ response to the Post’s columnist who asked her for her thoughts on Barnes’ paper. She was honest in telling him what she thought. Aren’t scientists supposed to be honest?
My previous post obviously is in the wrong place.
Her “response,” that was “her thoughts on Barnes’ paper,” in response to a question from a columnist who asked for her “thoughts,” was not her response to Barnes?
Your post is not only in the wrong place, it is…OK, I won’t say what first came to mind, because that would be mean. But I will say – confused.
GaryM, I will say the first thing that comes to my mind.
It’s not exactly the same thing, but your inability to see the difference doesn’t surprise me.
Many are concerned with the “loss” of ice, many cheering about the “gain” of ice. You may as well fear loss of darkness or gaining of light each day. The Arctic ice advances and retreats in cycles, does it not? Is somebody seriously trying to say it did not advance after the fifties and retreat after the seventies? Tambora or no Tambora, did it not retreat very substantially after the Napoleonic Wars? Yes or no? Or did Banks and the Royal Society imagine that? Wasn’t there a bunch of Arctic ice by the end of the 19th century, but a whole lot less after WWI? If the present retreat is more (or less) extensive, so what?
Even if none of this is so, a “scientist” would have to be intensely interested in past fluctuations as a primary matter for inquiry. Instead, most treat the past like a faded sepia photo, lost in a drawer, somehow of less importance. In fact, the past is equal to the present. Same planet, same poles. There were no satellites whizzing overhead in 1817, but – don’t be surprised now! – it was the very same planet. Don’t have enough info on past conditions? Fine. Don’t beat yourself up. If you do not have enough information about the past, then you do not have enough information. What bad luck! It is clear then that you should not pronounce, and, above all, you should not not publish. We’re talking about climate, not those shorter 20-30 year cycles which bring back new versions of The Locomotion.
I’m perfectly open to be informed of the period when climate, Arctic ice etc were stable and as they should be. Was it 1980 (popular choice for satellite gazers)? 1950? It certainly wasn’t the 1930s. So, when was the climate normal? After all, it would be folly to attempt a return to a norm which does not exist. Me, I’d like to get back to that golden period of 2007 to 2012, at least in my little part of the world. Cooler summers, plenty of rain…that’s for me! Sadly, I know it’s not a norm, just more stuff that happens.
The global coupled atmosphere–ocean–land–cryosphere system exhibits a wide range of physical and dynamical phenomena with associated physical, biological, and chemical feedbacks that collectively result in a continuum of temporal and spatial variability. The traditional boundaries between weather and climate are, therefore, somewhat artificial. The large-scale climate, for instance, determines the environment for microscale
(1 km or less) and mesoscale (from several kilometers to several hundred kilometers) processes that govern weather and local climate, and these small-scale processes likely have significant impacts on the evolution of the large-scale circulation.http://journals.ametsoc.org/doi/pdf/10.1175/2009BAMS2752.1
So you’re still intent on bad mouthing Kylie? 1817 was in fact the year without a summer. It is the one where whales frolicked amidst icebergs with 2nd fleet surfers off Bondi Beach. A time traveling Kylie wore her magic silver ugh boots – http://upload.wikimedia.org/wikipedia/commons/5/54/Kylie_Minogue_in_an_Aphrodite_costume.jpg – . Seriously – how can you not want to just lick her all over like an ice cream? It is pretty much what they are complaining about in Minnesota – the no summer not the Kylie licking. But let’s face it – what happens in Minnesota is ultimately in the realm of who cares. It might as well be a different planet. In fact it is probably the one you live on Moso. Somewhere out near Beetle Juice. Not a Chysler fin, a six shooter or a Kylie Queen in sight. Just down at heel bourgeoisie wondering why the hoi polloi keep laughing.
To set you straight yet again – climate is the new weather.
A technicality: I am not a down-at-heels bourgeois. I am a down-at-heels toff.
Also, 1816 was the year without a summer. The cold was doubtless helped along by Tambora, but it was pretty bloody cold anyway around that time. 1817 was the year Banks announced a radically opening Arctic. Volcanoes are handy for explaining stuff you don’t know much about. I’m sure there’s a theory floating about that Tambora melted the ice. Whatever.
Joseph Banks was a true toff, once of my ilk, so I tend to believe him. There’s some gossip that he tried to smuggle a courtesan, disguised as a flute player, on board the Endeavour. Never mind whales, save the toffs!
I am routinely meticulous in checking my usage – although somewhat given to poetic license. ‘Across the globe during the so-called “Year Without a Summer”—which was, in fact, a three-year climate crisis—harvests perished in frost and drought or were washed away by flooding rains.’ http://www.branchcollective.org/?ps_articles=gillen-darcy-wood-1816-the-year-without-a-summer
Similarly with bourgeoisie. I took the model as Molière’s ‘Le Bourgeois Gentilhomme’ – http://en.wikipedia.org/wiki/File:Le-bourgeois-gentilhomme.jpg – and not the latter day existentialist perversion of the term. The wealthy upper stratum of the middle classes – and not the landed and titled gentry.
Let’s face it – a class that everyone feels entitled to laugh at. One rung lower and the become missionaries. My partner comes from a little island called Misima. She is still faintly embarrassed that they ate the first missionaries to arrive. They are reputed to taste like sour grapes. As for the Arctic – I can only suppose that Sir Joseph Banks was too busy buggering cabin boys and sent the cook up to watch the ice. And regret that he failed to stop in at Misima on the way.
If I have this wrong – I’ll just sardonically tug my forelock Lord Moso.
Perhaps Jennifer Francis has detected a lack of objectivity in the paper. A series of errors that suggest a non-objective intent.
Perhaps. However, even in this case it is the most stupid way imaginable to launch a counter attack, I mean by attributing dark intents and motives to Elizabeth Barnes. Like her paper was a “direct attempt to disprove the work of presented in Francis and Vavrus (2012; hereafter FV12)”. Why, of course it was. That’s what scientists do.
She should have restricted herself to technical details, showing, by data & logical analysis, that this “direct attempt to disprove” has failed this time. However, she has done nothing like that, just thrown in some references to figures in Barnes, 2013, then went on with her innuendo.
Personal attacks add nothing to scientific progress, debugging does.
” The Arctic ice advances and retreats in cycles, does it not? Is somebody seriously trying to say it did not advance after the fifties and retreat after the seventies?”
To borrow what should become the new hot catch phrase of the climate wars from Willis Eschenbach at WUWT:
Because science.
The Arctic was open in the 14 hundreds and then there was the Little Ice Age and recently it has opened again.
The interesting part of this is that if the comment had been the other-way round, ie if Barnes had questioned the motivation of Francis, the climate skeptic blogs would full of celebrations about it on their blogs. Inhofe would have the letter put up on Climate Depot. They’d all be cheering Barnes for “exposing the hoax”.
It’s only because the the questioning of motivation comes in a direction inconvenient to climate skeptics that they are voicing discomfort and acting concerned, trying to play the moral high ground. As if they’ve never dreamed of questioning scientist’s motives before!
Judith writes: “I haven’t seen an attack like this on a scientific paper that directly questions the motives of the author”
You haven’t been reading climate skeptic blogs then?
Okay sure, you are talking only about scientists. But then it’s another example of one rule for climate skeptics another rule for climate scientists isn’t it. Which comes down to a rank issue. The fact that despite what they want to believe, climate skeptics do not have the credibility to lose in the first place, whereas climate scientists do.
climate skeptics do not have the credibility to lose in the first place, whereas climate scientists do
I believe that as of now, with Climate Models failing for decades, it is the other way around. Climate Scientists no longer have any credibility to lose.
+10
You sound much more reasonable than the usual greenie meanies that drive prius (drivers of which have been found to be the rudest). These are the ones that will come for me when I am 90 and tell me I have run out of carbon credits and it is time to die.. for the planet.
I would like to hear your rection to the idea that co2 is good (plants like it).
Some evidence suggests a greener warmer world would be a good thing..
How about the idea that co2 rising is a reaction to warming (which the sun is obviously responsible for).
We are actually starved for co2… hot houses pump the stuff in…
Why are the other planets in our solar system getting warmer? Lots of suv drivers on those worlds…
***She calls Barnes’ approach “less than objective” and “a direct attempt to disprove work” she authored.***
We’ve heard this from the hockey team before and I think the use of the idea that someone is trying to “disprove work” should be trademarked by the team. This IDs Francis as a member.
Scientists should TRY to disprove each others work. That’s the acid of science. That’s what makes science shine above other attempts to find the truth.
mm yeah ice metls in the summer.. it comes back in the winter…
“The winds change the ocean currents which in turn affect the climate. In our study, we were able to identify and realistically reproduce the key processes for the two abrupt climate shifts,” says Prof. Latif. “We have taken a major step forward in terms of short-term climate forecasting, especially with regard to the development of global warming. However, we are still miles away from any reliable answers to the question whether the coming winter in Germany will be rather warm or cold.” Prof. Latif cautions against too much optimism regarding short-term regional climate predictions: “Since the reliability of those predictions is still at about 50%, you might as well flip a coin.”
http://www.sciencedaily.com/releases/2013/08/130822105042.htm
From a new ‘model study’ on the 19976/77 and 1998/2001 climate shifts from Latif and colleagues. On the other hand the mind is much more subtle in identification and extrapolation of patterns. These climate shifts added to global temperatures in the period between the shifts and was amplified in the Arctic, the US and Europe. It is leading to moderation of global temperatures currently – and should lead to cooling over decades especially apparent in high NH latitudes. The regimes explain ice and temperature variability in the Arctic far better than sulphides.
On the other hand winters in the NH have been pretty intense over the past decade. It is related to the position of the mid latitude jet stream and thus somewhat influenced by the state of sea level pressures in the Arctic.
‘The Arctic Oscillation (AO), shown below, is an important Arctic climate index with positive and negative phases, which represents the state of atmospheric circulation over the Arctic. The positive phase (red) brings lower-than-normal pressure over the polar region, steering ocean storms northward, bringing wetter weather to Scotland and Scandinavia, and drier conditions to areas such as Spain and the Middle East. While the value of the AO index was strongly positive in the early 1990’s compared to the previous forty years, the value of the AO has been low and variable for the last nine years. The year to year persistence of positive or negative values and the rapid transition from one to the other is often referred to as “regime-like”. http://www.arctic.noaa.gov/detect/climate-ao.shtml
Lockwood et al (2010) – http://iopscience.iop.org/1748-9326/5/2/024001/fulltext/ – ascribe the relationship between Central England Temperature (CET) to solar activity.
The results presented in section 4 allow rejection of the null hypothesis, and hence colder UK winters (relative to the longer-term trend) can therefore be associated with lower open solar flux (and hence with lower solar irradiance and higher cosmic ray flux). A number of mechanisms are possible. For example, enhanced cooling through an increase in maritime clouds may have resulted from the cosmic ray flux increase [25]. Alternatively, tropospheric jet streams have been shown to be sensitive to the solar forcing of stratospheric temperatures [26]. Solar forcing of the stratosphere is via ozone/UV interactions.
There seems little doubt that an open Arctic is a source of increased NH rainfall. Judith Curry has a study on this.
However, the atmospheric circulation change linked to the reduction of sea ice shows much broader meridional meanders in midlatitudes and clearly different interannual variability than the classical Arctic oscillation. This circulation change results in more frequent episodes of blocking patterns that lead to increased cold surges over large parts of northern continents. Moreover, the increase in atmospheric water vapor content in the Arctic region during late autumn and winter driven locally by the reduction of sea ice provides enhanced moisture sources, supporting increased heavy snowfall in Europe during early winter and the northeastern and midwestern United States during winter. We conclude that the recent decline of Arctic sea ice has played a critical role in recent cold and snowy winters.’ http://curryja.files.wordpress.com/2012/03/pnas.pdf
A combination off factors but – a priori – either leads to an increase in mid-latitude blocking patterns. The CET is clear evidence of North Atlantic variability and has changed dramatically since 2000. I think Jennifer Barnes might be wrong – but still the Arctic changes seem more natural than anthropogenic. I wonder as well if ‘increased moisture sources’ create the potential for decreased thermohaline circulation, further cooling and ice sheet growth in the NH.
Chief, ” On the other hand the mind is much more subtle in identification and extrapolation of patterns.”
That makes it a fun puzzle. Also one of the reasons that three or more methods are needed to make sure what the mind sees is not a phantom.
That and you toss a coin!!!!
Chief, knowing when to flip a coin is half the battle. But at a higher energy level, the odds move to down and at a lower energy level the odds move to up. Once you know what “average” is, the real coin toss, you can get ahead in the game.
@Chief..jeez just write a book.. what exactly are you saying?
I wanted to indulge in a serious discussion of the topic.
There are processes that have influences on decadal scales. Climate shifts in 1976/77 and 1998/2001 are inflection points for trajectories of global and Arctic temperatures – and involve changes in Pacific Ocean indices.
These might be related to polar fields – the Northern and Southern Annular Modes – through solar UV forcing of stratospheric ozone. I would suggest modification of the north and south Pacific gyres through the same mechanism that changes the location of the mid-latitude jet streams. More or less cold water pushed into the Californian and Peruvian Currents.
The latter suggests longer term amplification of solar variability – but certainly seems part of the reason for more recent NH cold winters.
Chief Hydrologist,
Please excuse me, but : –
You said “I wanted to indulge in a serious discussion of the topic.
There are processes that have influences on decadal scales. . . ”
– and then followed this with the usual maybes and suggestions, and threw in a definite more or less, for good measure. We are still in the dark as to the nature of these mystical “processes”. Any fool can propose any number of cycles, oscillations, or repetitive processes to explain variations of natural,occurrences. It requires a special kind of fool to explain the causes of the cycles, oscillations, and so forth, in such a way as to make them useful. Analysis of past data using methods ranging from “eyeballing” to sophisticated statistical analysis can reveal all sorts of cycles and patterns which turn out to have precisely zero utility in predicting the future.
Unfortunately, the left hand side of the graph is no guarantee as to the shape of the graph yet to come.
Have you anything a little less nebulous to contribute? A different hypothesis? A logical (or even illogical) critique of the status quo? Something which may actually advance the cause of science?
On the other hand, you may exercise your mental faculties trying to devise some fresh epithets, (in the sense of abuse), or other aspersions to cast my way. If you can come up with something witty, or at least novel, I would be most appreciative.
Live well and prosper,
Mike Flynn.
I cast aspersions because you are waste of time – replete with mad theories and a line in obfuscation, dissimulation and sardonic sneers.
The short exposition was here because because fred asked. The longer discussion is just above. Starting with a new Latif paper. The clues are ‘climate shifts’ and ‘tossing a coin’ – but some people I expect to remain clueless.
Chief Hydrologist,
As usual, you cannot provide a single fact to back up your assertions. If you choose not to answer reasonably simple and easy to understand questions, this could be taken as an indication that you have no cogent answers.
Alternatively, you may be allowing your emotional response to comments by my good self to cloud your objectivity. It is of little consequence to me. I am surprised that you choose to waste your time and effort in tossing mindless (and frankly, quite childish), invective and insults in my direction.
I am curious – what is it that you are intending to achieve?
Live well and prosper,
Mike Flynn.
As usual you indulge in mindless obfuscation and long winded whines.
Read the post – full of science heavy on interpretation and relevant to the post – and p_ss off. I don’t really care
http://judithcurry.com/2013/08/21/arctic-sea-ice-and-weather/#comment-368036
Reducing CO2 would reduce the world food supply and would only change temperature and sea level rise a fraction of a trace. Water is Abundant, in all of its states, and being able to change state in our comfort zone regulates the temperature of earth. When Climate Models fail to forecast correctly for decades, it is time to question how bad they really are. No temperature or sea level data is out of bounds. Ice core data shows that temperature has been inside plus and minus one degree C for most of the past ten thousand years. Ice core data shows that temperature has been inside plus and minus two degrees C for all of the past ten thousand years. This is true for Greenland and Antarctic Ice core data. Modern temperature is inside the one degree and not headed out. The only thing that is out of bounds is Climate Model Output. They trust the output from their computer even when it does not match reality.
Climate temperature goes up and down and up and down. Climate Model Output goes up and up and up and up and never comes down. Climate Data has regular cycles. Climate Model Output is smooth. Their curve fits were developed during the warming period between the little ice age and now using 130 years of thermometer data. Their curve fits extrapolate up and up and up and don’t know that down follows up.
Look at some model output.
http://popesclimatetheory.com/page5.html
Look at some real data
http://popesclimatetheory.com/page6.html
http://popesclimatetheory.com/page9.html
Their model output looks nothing like real data.
That is because it is not anything like real data.
They do not know that the warm times are necessary because that is when snow falls to rebuild ice volume on earth. The data knows that and those of us who look at and understand data recognize it snows more in warm, wet, times and snows less in cold, frozen, times. You can see this in the data. After it snows more for the years in a warm time, it always gets cold after because the ice advance later after it develops sufficient volume.
Maurice Ewing and William Donn figured out this ice cycle and published this in the 1950’s and 1960’s. Most modern consensus climate scientists did not get taught the theory of Ewing and Donn. Some of our Climate Study Group went to a lecture by Michael Mann at Texas A&M. Some of his past students were also there. I talked to them after the lecture and none of them were familiar with Ewing and Donn and their ice cycle theory that ice advances after large snowfalls during warm times and that ice retreats after the polar oceans freeze and the snowfall stops. This is clearly shown by the ice core data and this was not even available to Ewing and Donn when they created this brilliant Theory.
Yes, glaciers are still retreating because this is still a warm time. The snow is already falling on the heads of these glaciers that will cause them to again advance later. Their ice volume is now increasing. Ocean sea levels have stopped or will stop rising soon. Earth Albedo has stopped decreasing. We are in a warm time much like the Roman and Medieval Warm times and snow falls in the warm times and that causes the next cold times.
I have studied Maurice Ewing and William Donn Climate Theory since April of 2008 when Tom Wysmuller lectured our Johnson Space Center Alumni Association about Ewing and Donn Theory.
http://www.colderside.com/Colderside/Home.html
Tom gives credit to Al Gore for getting him started in Climate Study. Tom was already a Meteorologist. Al Gore did more to waken Skeptics than anyone else has. If Gore was not on the Consensus Team, they might have slipped this CO2 science past us for a lot longer.
John N-G is already part of our Climate Study Group. We are not a consensus group. We have people from different sides with different Theories. There are more than two sides. The rest of you should consider joining.
http://www.therightclimatestuff.com/
In order to mitigate, adapt and/or suffer, we need to understand what really causes what before we introduce the absolute wrong fix and increase the suffering.
The Consensus People are highly confident that they know what is going to happen because their models tell them. These are the same models that have failed for decades now.
Question for Climate Scientists. You say we were not supposed to warm and we only did warm because of the extra man-made CO2. Explain why this time we were not supposed to warm like we always warmed after every cold period in the past ten thousand years.
I know why. Computer Curve Fits do smooth the data of the past ten thousand years. According to model output, none of the up and down cycles should have been there. Michael Mann did that and he was called on it and the IPCC was forced to take his Hockey stick out of their report following the one it was included in.
Climate Scientists still say this warm period should not have happened. They put the Medieval Warm Period and the Little Ice Age back in the data Michael Mann used. That means this warm period was supposed to happen.
They smoothed out the past cycles and that caused them to smooth out future cycles. That makes this normal warm period to be not normal.
Temperature and sea level are just where they should be in this phase of the climate cycle that keeps repeating.
So, what we have is a hockey stick, but this hockey stick is ten thousand years old. You need to put the past warm and cold periods back in the past data and look at what a proper curve fit projects forward.
This Warm Period and Sea Level Rise and Open Arctic is normal and natural and clearly shown to be so, in the actual data.
Get rid of the ten thousand year Hockey Stick.
There was a quote from Judah Cohen in this posting.
Judah Cohen has written multiple really good papers on Arctic Sea Ice and Weather. Read some of them and pick out your own quotes.
http://web.mit.edu/jlcohen/www/papers.html
Re: Arctic Sea Ice. No record this year, and note the storm.
Samenow, Jason. “Arctic Sea Ice Loss Dramatically Slows; Record Minimum Unlikely in 2013.” News. Washington Post, August 9, 2013. http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2013/08/09/arctic-sea-ice-loss-dramatically-slows-record-unlikely-in-2013/
Please excuse me for this somewhat off topic post.
It occurs to me that the Earth’s average surface temperature, (however defined) must have been at some point 2C higher than now. I know I am stating the obvious, but some people refuse to accept that the Earth has cooled from its creation to now, and you can’t skip temperatures on the way down. The average surface temperature had to pass through 1000C, 500C, 300C, and so on.
Is there any research that indicates what the conditions around the globe were during the periods of higher temperature regimes? If not 2C hotter, then 10C, or something in between.
It would be interesting to know this, as there seems to be some trepidation about a future rise of temperature of a couple of degrees. As it has certainly happened in the fairly recent past as the Earth cooled, what were conditions like throughout the world.
I have searched as best I can, but I don’t have academic access, which at least some of the commenters on this blog obviously have.
There are some studies about localised archeo climate, but given a particular date BCE, research shows only that one locality was warmer, another was colder, and so on. Nothing about the global temperature.
Can anybody help?
Live well and prosper,
Mike Flynn.
Warming one decade,
pausing the next,
causing the warmists
ter feel very vex’t.
Here’s hoping we’ll soon
be a little bit warma
’twill cause the alarmists
ter feel a bit calma.
They long fer a tipping point
their theory ter vindicate,*
take us back ter a golden age,
disregard the next Ice Age
when our inter-glacial-warming
disappears inter space.
* and behaviour of Climategate.
Verses from the field by beth the serf.
Oh dear, what can the matter be,
Global warming has gone down the lavatory,
They thought that they saw it last Friday or Saturday,
Now it’s gone goodness knows where!
Live well and prosper,
Mike Flynn.
Let,s get this right. Arctic sea ice melts from the bottom and edges. When the currents are warmer more ice melts. The decline in arctic sea ice is a consequence of transferred warming from elsewhere in the ocean as will be the re growth of arctic ice when the full value of the colder La Nina’s of recent times comes through.
But extreme weather? Extreme weather is something that happens once every twenty years. (Angech definition).
Proof is cyclones in Australia. Darwin, the capital city of the Northern Territory is hit by a major cyclone roughly every 20 years. There are a lot of cyclones every wet season but the path of such storms is such that there is only a 5 percent chance of one of them hitting the same spot in a year.
Shifting this concept to the North one old have to show that extreme events are happening more than 5 percent of the time to the whole of the area being considered.
Going south to great storm Sandy such events have happened before, will happen again and will always have an excuse (sorry, reason) such as a blocking high or a freeing low or two fronts/three fronts merging or moving apart. It’s called weather.
The key point is, is it more or less common than 5 percent. As I understand it Hurricanes are at a low in recent years and there is no evidence of extreme weather other than the usual extreme weather of yore.
Landfalling storms may be at a low, but the number of named Atlantic storms have been at an almost persistent high since 2000. It has been active out there with no sign of slowing.
Signs of slowing?
POLICLIMATE: Global Tropical Cyclone Activity, Ryan N. Maue, PhD
2012-2013 Activity Updates http://policlimate.com/tropical/index.html
Global Hurricane Frequency (all & major) — 12-month running sums, updated July 31, 2013
http://policlimate.com/tropical/global_major_freq.png
Last 4-decades of Global and Northern Hemisphere Accumulated Cyclone Energy, updated July 31, 2013
http://policlimate.com/tropical/global_running_ace.png
Actually I was talking about the Atlantic where 10 of the 15 seasons with the most named storms (15+) have been since 2000, including the last 3 years.
And that certainly has nothing to with our ability to detect storms or a bureaucratic decision on naming storms.
Tell me Jim, were the number to triple, without any making landfall, what would there be to worry about?
You are correct in that you wrote of the Atlantic storms, and I provided references to Dr. Maue’s global and northern hemisphere activity (storms).
Introducing the graphs, Dr. Maue observes “In the pentad since 2006, Northern Hemisphere and global tropical cyclone ACE has decreased dramatically to the lowest levels since the late 1970s. Additionally, the frequency of tropical cyclones has reached a historical low.”
Of course, the regions graphed by Dr. Maue do not correspond to the region to which you refer. Dr. Maue’s graph of “Global Running ACE” is interesting to me because it shows overall decline in both Global and Northern Hemisphere for the 15 seasons you cited.
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Thank you all for your interest in this emerging research topic.
I’d like to begin by apologizing for questioning Dr. Barnes’ intent. I was wrong, and I’m sorry. Let’s move on.
If I could submit a comment on the paper to GRL, I would, but unfortunately they do not accept comments. Instead, I am working on a paper to present new evidence linking Arctic amplification to changes in the large-scale circulation, but papers take a while to get through the pipeline. In the meantime, I’d like to elaborate on my thoughts about Libby Barnes’s new work, whose main conclusions are that “…previously reported trends [in meridional extent of atmospheric waves over North America and the North Atlantic] are an artifact of the methodology” and that “the mechanism put forth by previous studies (e.g., Francis and Vavrus [2012] and Liu et al. [2012]) that amplified polar warming has led to the increased occurrence of slow-moving weather patterns and blocking episodes, is unsupported by the observations.”
This paper contains some very illuminating findings. Figure 2 shows time series of wave extent (i.e., north-south amplitude) for fall (OND) and summer (JAS) using two different metrics applied to the 500 hPa height contours used in FV12 as well as to the isopleths that represent the “waviest” 500 hPa heights. In 11 of 12 curves in this figure, the trends are positive, i.e., wave amplitude increased. Not one exhibits a negative trend. I recognize that only 3 of 12 are statistically significant, but the overall picture seems to be one of increasing wave amplitude, in agreement with our results. Figure 4 demonstrates significantly reduced zonal winds at 500 hPa during fall along with decreasing wave speeds, which also support our proposed mechanism. It is not surprising that the other seasons do not behave similarly, as Arctic amplification is strongest and most polar-centric in fall, but it’s increasing in the other seasons, as well. In Fig. 4c it would have been a more apples-to-apples comparison to show wave speeds based on 250 hPa heights rather than winds, as the patterns at 500 and 250 hPa are usually very similar.
The real crux of the matter is illustrated in Figure 3, but it’s not easy to understand. The blue and red curves are for an earlier and later time period, and they show how much “waviness” exists at various height isopleths of the 500 hPa surface. The gray horizontal shaded bars depict the height isopleth used in FV12 for each season, where the amplitudes increase with time. The plot clearly shows that the waviest isopleths (blue and red dots) are lower in altitude (smaller numbers on vertical axis) than the ones we selected, and that the level of maximum waviness is rising over time. We chose the heights we did because they represent the climatological core of maximum poleward gradient at 500 hPa – and strongest winds – to best capture the shape of waves in the jet stream. The heights of maximum waviness, however, are actually about 15 deg latitude farther north and well out of the strongest gradient. Zonal winds are much weaker in this zone, so it’s no surprise that they’re also wavier. The more northern but waviest isopleths also do a poor job of capturing the shape of the jet stream waves. Perhaps the conclusions of the Barnes paper are also an artifact of the methodology.
I found it surprising that the paper’s abstract (which is the only part that many people read) does not mention any of these important findings.
Thank-you again for your comments and suggestions.
I am interested to see further work in this area. I especially would like to see if a similar signal is found in Western Europe, as I have only seen speculation by the Met Office to this effect on Arctic changes causing more easterly winters that are colder and snowier, as they have seen recently.
Hi Jim — This recent paper of ours may provide some useful information as well as other relevant papers in the bibliography: http://iopscience.iop.org/1748-9326/8/1/014036/
Much to the point and nice that it is open access. Thanks. I will read it with interest.
Wow, that’s what I was exploring for, what a stuff! present here
at this blog, thanks admin of this website.
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