Guest Post by Willis Eschenbach
There’s a paper out by, inter alios, our good friend Judith Curry. The paper is “Impact of Declining Arctic Sea Ice on Winter Snowfall”, by Jiping Liu, Judith A. Curry, Huijun Wang, Mirong Song, and Radley M. Horton (PDF, hereinafter L2012). Judith has a thread discussing the paper at her excellent blog. Their claim is that reducing Arctic sea ice leads to heavier winter snowfall. Inherently, this seems to make sense. Less ice means more evaporation, and because what goes up must come down, more evaporation means more snow. Case closed … or not …
Unfortunately, the paper doesn’t live up to its promise. Oh, it has lots of pretty pictures. Here’s one of them:
Figure 1. According to L2012, this shows the difference between the outputs of two climate model runs. I would call this is pretty conclusive evidence, perhaps even the long-sought “smoking gun”, that clearly establishes that the two climate model runs were indeed different.
Here’s what their abstract has to say (emphasis mine):
Abstract
While the Arctic region has been warming strongly in recent decades, anomalously large snowfall in recent winters has affected large parts of North America, Europe, and East Asia. Here we demonstrate that the decrease in autumn Arctic sea ice area is linked to changes in the winter Northern Hemisphere atmospheric circulation that have some resemblance to the negative phase of the winter Arctic Oscillation. However, the atmospheric circulation change linked to the reduction of sea ice shows much broader meridional meanders in mid-latitudes 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 mid-west 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.
So … what’s not to like? Reduced ice causes cold surges, leading to more snowfall. Case closed … or not …
For me, the first clue that something is wrong in a study is often that they don’t start out with a historical look as far back as the records may go. In this case, the satellite ice area as records go back to 1978. But in this study, they only show snow records going back as far as the antediluvian year of 2007/2008 … at that point, the bells started ringing for me. I always start with the longest overview of the question that I can find.
So let me remedy that, and we can see if declining sea ice really does lead to cold, snowy winters. The upper panel of Figure 2 shows the actual ice and snow data (normalized to an average of zero and a standard deviation of one). Below that, the lower panel shows the anomalies in those same normalized datasets once the monthly averages have been removed.
Figure 2. Arctic sea ice area (blue) and Northern Hemisphere snow area (red). Upper panel shows actual data. Lower panel shows the anomalies of the same data, with the same units (note different scales). The R^2 of the snow and ice anomalies is 0.01, meaninglessly small. The R^2 of the first differences of the anomalies is 0.004, equally insignificant. Neither of these are significantly improved by lags of up to ± 6 months. SNOW DATA ICE DATA
I’m not going to say a whole lot about this graph. It is clear that in general the arctic ice area has been decreasing for twenty years or so. It is equally clear that the northern hemisphere snowfall has not been increasing for the last twenty years. Finally, it is clear that there is no statistical relationship between decreased ice and increased snow.
I will leave it to the reader to decide if, as the authors of L2012 say in the Abstract, ” the recent decline of Arctic sea ice has played a critical role in recent cold and snowy winters.” I certainly don’t see it in the historical record. And this is why graphing the full record of both variables is so important. There may be some effect there … but if so, it is a very small effect, it’s invisible at this level.
In a more general sense, I see this as studying “how many snow-storms can dance on the head of an iceberg”. There have been no breakthroughs in climate science in thirty years, and I can see that the people searching for the “smoking gun” establishing a “human fingerprint” are getting mighty frustrated. But that is no reason to give up on the important questions and work on this kind of trivia. If there were a significant effect of decreasing ice causing increasing snow area, it would be visible in Figure 2. So at best, they are studying some tiny, third-order phenomenon. There’s nothing wrong with doing that once a field has no big questions left unanswered.
The thing is, climate science is nothing but unanswered questions, big questions. And until those questions have answers, for them to be wasting their valuable time and their trained scientific curiosity on this kind of small potatoes?
I suppose it’s meaningful in some universe … not mine.
w.
PS—The authors do deserve kudos, however. The paper nowhere contains the words “human influence”, “AGW”, “anthropogenic”, or “CO2”. That alone is shocking enough that it should get a medal of some kind.
PPS—Joe D’Aleo discussed the L2012 paper on WUWT here. Unfortunately, he didn’t show a direct comparison between ice and snow either.
PPPS—The title is from Mae West, who said “I used to be Snow White … but I drifted.”
MFKBoulder says:
March 6, 2012 at 7:00 am
What cyclical signals are you referring to?
w.
I have issues with the references to Canadian geography (or the lack thereof) in this paper.
The Abstract seems to skip the 2nd largest country (aka “Americas Hat”) on the planet entirely. How the snow extent can differentiate between northeastern US and southeastern Canada is an interesting conclusion — maybe snow can read a map of the irregular border for 1/2 the continent better than I can.
Also: “The only notable exception is northeastern Canada and Greenland, where weak westerly winds favors more frequent incursions of warm air masses from the North Atlantic. This leads to warm anomalies there (Fig. 2C), helping to explain extremely low ice coverage observed in Baffin/Hudson Bay, Davis Strait, the Labrador Sea, and Gulf of Saint Lawrence in recent winters,
particularly in 2009–2010 and 2010–2011” — this is a pretty big exception since I believe the area they refer to is greater than Europe.
This macro-assessment of Canadian geography is totally counter to what any Canadian and Environment Canada knows about the Canadian climates (emphasis on multiple climates) e.g. every major city (>200K’s people) in Canada is pretty well in its own climate zone never mind the Northern hinterlands. Papers that refer to Canada’s with this kind of granularity lose credibility with me personally — and may be why so many skeptics are Canadian.
Replicant says:
March 6, 2012 at 8:27 am
No, I don’t think that. I rarely even use the term “debunked” because it is so emotionally loaded. Your attempt at mind-reading what I think is an abject failure, don’t quit your day job.
w.
steven mosher says:
March 6, 2012 at 9:22 am
Steven, you seem to specialize in drive-by, mildly unpleasant, and most importantly, often unintelligible posts.
If you want to clarify that pile of meaningless nonsense, please do so. You’re a smart guy, and you may have a point, but if so, it is invisible.
Otherwise, I’ll ignore it.
w.
PS—The phrase “equivalent water”, and the word “equivalent”, do not appear anywhere in the paper. You see the problem with your bogus posting style? It just makes you look like you are clueless. I’ll assume you are talking about “SWE”, or snow water equivalent. This is the amount of water contained in a certain amount of snow.
But since Judith never uses the term … then why on earth are you talking about it?
And “regional” is used twice, once in the reference list, and one referring to one of the references.
You must think your posting style makes you look mysteriously oracular. It just makes you look dumb.
Three words; explain; your ideas.
w.
Split flow jet streams and blocking patterns? That’s sooo 2010/2011. Didn’t you know the latest result of global warming is “Superjets?” Yeah. “Superjets.” Formerly known as a “phased jet stream,” that is until yesterday…
From the blog of Jeff Masters:
“Dr. Jonathan Martin of the University of Wisconsin-Madison is doing interesting research on the type of situation we saw with some of the recent severe tornado outbreaks, when two branches of the jet stream, the polar jet and the subtropical jet, merge to form a “superjet.” In a December 2011 interview with sciencedaily.com, he said: “There is reason to believe that in a warmer climate, this kind of overlapping of the jet streams that can lead to high-impact weather may be more frequent.””
So, you see, the “Superjet” is supposed to become more frequent, not blocking. At least it will be until the next heat wave.
Agnostic says:
March 6, 2012 at 10:40 am
Here’s what the paper says that they are using:
See the part where it says “snow extent”? That’s where I got my figures from that I used in the graph. I rest my case that they are using extent.
w.
“Here we demonstrate that the decrease in autumn Arctic sea ice area is linked to changes in the winter Northern Hemisphere atmospheric circulation that have some resemblance to the negative phase of the winter Arctic Oscillation. However, the atmospheric circulation change linked to the reduction of sea ice shows much broader meridional meanders in mid-latitudes and clearly different interannual variability than the classical Arctic Oscillation.”
So we have it is regional claims on this thread not NH, but the AO and NAO affects the entire NH not just these regions of NE USA, SE Canada, parts of Asia and Europe. A broader meridional in mid-latitudes does give different yearly variability than the classic AO, but the AO needs to be going in the same direction that this claim is made. Over the long term since arctic ice was declining the AO has become increasingly positive not negative. The increased snowfalls require a negative AO for this increased different atmospheric circulation to be possible.
Yet we have declining Arctic ice since the 1970’s and wait for it an increasing postive AO during this time, except the last few years. Again like in my previous post the only possible link related to other data time period is the extended solar minimum.
http://upload.wikimedia.org/wikipedia/commons/1/13/Arctic_Oscillation.svg
Ágúst in Iceland and Willis’ PDF discuss the accuracy of the Temperature measurement.
To transmit (or record) the data some form of Analog to Digital (A/D) conversion is required which will limit the precision. For example a typical industrial A/D card converts to a 12 bit word i.e. a resolution of 1/4096 (1/(2**12)). The measured resolution will, of course, vary with the range of temperatures the card is set up for. Add to this the accuracy of the electronic design and components.
Some other sources of error (among many) may be found in allowing for non linearity in temperature to sensor output, thermocouple cold junction compensation and simple transmission errors.
Finally, I will mention processing errors such as: data entry, fixed or floating point arithmetic, truncation or rounding….
Sign me a retired controls engineer with too many scars
Willis
I have supplied Judith with masses of sea ice data for the 1918 to 1939 arctic melting and also snow extent. If her hypothesis holds she should be able to determine if this episode of arctic melting did what she thinks it should.
I don’t have a dog in the fight, just interested to see if the facts match the theories.
tonyb
This paper seems to inter-change snowfall and snow cover (even though all the data, as Willis points out, is snow cover related). These two are not the same and once again as a Canadian I will throw the challenge flag on this. You can draw an East-West line across Canada where above it you are expected to have snow cover (e.g. >95% chance) for January and February. But this doesn’t tell you anything about the amount of snow. For example, here in Ottawa we have had snow cover since before Christmas and still do but we are over 1 meter blow our average snowfall (50% of normal). Note: this is not abnormal as our snowfall varies a lot — what would be abnormal would be to see the grass in your yard (no snow cover).
Willis
I think Mosh might have picked up the phrase ‘equivalents’ from the comments section of the Curry thread. I have just come across it.
“steve fitzpatrick | March 5, 2012 at 9:08 pm | Reply
Judith,
Interesting paper. One thing I wonder about is if there might be a heat balance calculation which would be relevant. Lake effect snow near the great lakes results from substantial warming of the lakes in the summer months and heat carryover causing evaporation into the early part of the following winter. But I wounder, is enough heat being collected in the Arctic ocean as a result of lower ice cover to account for the increased (total mass of) snowfall? The arctic doesn’t really warm very much above 0C over the summer. The final figure in the paper shows modeled deviation of snowfall. The units say ‘mm’, but I am guessing mm equivalent water not actual mm of snowfall. Do I have that right?
curryja | March 6, 2012 at 8:18 am | Reply
Steve, yes mm equivalent water. The major impact on increased snowfall is from the circulation changes; secondary from the open water in the Arctic Ocean. The later needs more investigation. Cold winter air (maybe 30C) blowing over open water even at 0C will give a large evaporative flux.”
So can’t see it was in the original paper but it came up in the clarification in comments
tonyb
w – you say “There have been no breakthroughs in climate science in thirty years”.
Wrong. Perhaps you should have said: There have been no breakthroughs in “climate science” in thirty years.
There have been a number of breakthroughs in real climate science, the latest is
http://arxiv.org/abs/1202.5156v1 (submitted to Physical Review Letters)
comment on it is here
http://calderup.wordpress.com/2012/03/01/yet-another-trick-of-cosmic-rays/
AdderV said (March 6, 2012 at 3:12 am):
This blog is getting worse by the minute, stooping to a new low in every article.
I used to like to come here everyday, not so anymore. This once fine blog is drifting towards school yard bullying.
It pains me to realize that I agree with AdderV’s statement. Before reading any comments, I found myself wishing that Willis had omitted his last three paragraphs; comparing L2012 how many snow-storms can dance on the head of an iceberg” is “inciteful” rather than insightful. Ad hominem slurs reduce the power of argument and reduce respect for the author.
I fear Willis’ posts should be reviewed by an calm editor before appearing in this worthy blog.
REPLY: I reviewed it and pressed the button. Blame me then, but I didn’t see the commentary as “inciteful” at all. If you want “inciteful” read Grist or ClimateProgress. Here, we tend to go with comedy and fun analogy – Anthony
AdderV and the other trolls,
Here we have yet another poster who drives by ‘eats shoots and leaves’. Like Brad anonymous AdderV you are clearly only here to disrupt the thread. Do us all a favour and find somehere else to troll.
In regards to JC, some of us have been around on climate blogs a lot longer than most others here. I personally remember JC’s first posts on CA and challenged her back then about her advocacy along with Kerry Emmanual. To this day she still hasn’t explained why she jumped on the ‘Hurricane Katrina’ band wagon along with Trenberth & Co.
Septic Matt
“I can’t see where you have disputed any of the basic claims of the authors. ”
Willis is clearly disputing L2012’s computer model pre-written conclusions in this thread. I presume you mean ‘refuted’ rather than ‘disputed’?
KevinUK
Can you imagine the storm of frenzied AGW jowl-flapping that would erupt if Willis or Anthony were to propose an hypothesis based on only 5 years of data, from an available dataset of 30 years? The endless parroting of the “cherry-picking” accusation? But since its cutesy Curry with a troupe of camp-followers, instead its all obsequious praise and flattery from the AGW courtesans. I dont think so – this “study” is a load of infantile crap. A 2-year old could tell you that – “when there´s less ice there´s more snow?” Pull the other one!
I re-examined the paper and Willis is at least partly right: the only reference is the Rutger Data set which I happen to be familiar with and it is for extent only. The only mention of snowfall by volume is at figure 7 but it’s not clear what the source is. Clearly they looked at extent as well, but they were doing something more than examining it in conjunction with sea-ice which is what Willis has done with his graph.
Other than a reasonable and plausible mechanism, the paper seems to suffer from some information missing that might have cleared up the confusion.
Inter alia is common usage in English and other European languages. Inter alios/alias while technically correct as a reference to people is pedantic and tends to obfuscate.
Besides, in this instance, one could well be referring to people’s papers rather than the people themselves in which case inter alia is much more appropriate.
phlogiston wrote:
“I dont think so – this “study” is a load of infantile crap. A 2-year old could tell you that – “when there´s less ice there´s more snow?” Pull the other one!”
Accumulation on the Greenland ice cap from the historical GISP2 records. Y-axis is meter pr. year:::
http://klimaforskning.com/forum/index.php?action=dlattach;topic=206.0;attach=656;image
“I used to be Snow White”
But you drifted, Willis? ;-p
Willis — enjoy the read, have you looked at correlations between the *rate* of loss w.r.t. snowfall?
Barbara Skolaut says:
March 6, 2012 at 3:37 pm
“I used to be Snow White”
But you drifted, Willis? ;-p
======
Best Muse of the Day ; )
Let’s keep it simple fun in science.
Sadly, at the end of the day, the obvious fact of all this effort points to ignorance (aka –> Al Gore).
“I would call this is pretty conclusive evidence, perhaps even the long-sought “smoking gun”, that clearly establishes that the two climate model runs were indeed different.”
Priceless, Willis!
WUWT: Come for the science, stay for the fun.
I might be preaching to the converted, but doesn’t everyone know that the Gulf Stream keeps Northern Europe, America, and UK from freezing? However, before every mini ice age or glacial period the Gulf Stream stopped or changed direction because of the increase of fresh water coming from melting ice or rivers and land ice, that caused the places to freeze up. The planet did warm up before it froze up again. Plus other things of course, many variables that make it hard for weather men to give 100% long term predictions. But the sun don’t shine in Antarctica and the Arctic or the Arctic Circle for months during the winter and early spring. Then sometimes 22 hours during summer.
Hardly typical of the rest of the world, eh? Yes we are getting heaps of rain in Oz, and flooding, but that is typical of this ancient continent. But people will build on flood plains? Or on water fronts, volcanoes, and seismic trenches. It will be bush fires next as the added green growth dries out and some idiot comes along and lights a fire deliberately.
I feel very sorry for Professor Judith.
She seems to be such a nice lady, trying to do honest work, while living in, what shall I say?
“A vipers’ nest”? Nay.
“A covern of villians”?
Perhaps, “extended family of witch doctors” sums them up best.
Or the Catholic church at the time of friend Luther, perhaps?
Take your pick.
Life is not easy for a consensus laden, yet honest broker, trying to do good, honest work.
Oh, what a shame!
Give it up, dear professor!
Time to crawl out of the closet into the light and call it as you really see it.
Find a place to stand tall with you feet firmly placed on solid land and face the world bravely.
Here’s the abstract again, With bolding, mine not Willis’: anomalously large snowfall in recent winters has affected large parts of North America, Europe, and East Asia. Here we demonstrate that the decrease in autumn Arctic sea ice area is linked to changes in the winter Northern Hemisphere atmospheric circulation that have some resemblance to the negative phase of the winter Arctic Oscillation. However, the atmospheric circulation change linked to the reduction of sea ice shows much broader meridional meanders in mid-latitudes 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 mid-west 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.
I can’t see where you have disputed any of the basic claims of the authors. Clearly the emphasis is on changes in the distribution of cold and snow following declines in Arctic ice. You have clearly shown that something they clearly did not claim is clearly unsupported by the data. They could still be wrong, I won’t deny that, but your analysis does not show it.