Why Is Winter Snow Extent Interesting?

Just to be clear and avoid getting off on irrelevant tangents, snow cover did decrease from 1970 through 1989. Winter snow cover has returned to the unusually high levels of the 1970s. Summer snow cover has not returned to 1970 levels, but has not declined since 1989.

Could we get a close up view of the summer snow extent, like we did for the winter to see what tend looks like over the same period?

The X axis in the first graph is mislabeled. Are those weeks? Can you show data from 1970 -present?

‘When you’re in a hole, stop digging’ is a sound piece of advice.

Zender had a little lamb,
Its fleece was black as soot.
And everywhere that Zender went,
It’s sooty foot it put.

Leif,
Please feel free to do any statistical analysis you want, and share the results with us. If you want to repeat for the last 10 years that would also be appreciated.

I notice that you only cite NH snow extent. What does SH look like?
Does measuring snow extent give any indication of temperature trends in Arctic and Antarctic? Or is this more of a measure of mid-latitude variation?
What would slope for winter snow cover look like without 2010, i.e., how much flatter might it be?

Leif Svalgaard (07:16:08) :
I was going to write something about fish and barrels, but the analogy rather breaks down when the fish start shooting themselves.

“Caleb (07:47:41) :
I assume that when snow reflects sunlight the sunlight doesn’t change into infrared waves, but remains the same long(?)-wave radiation it was on the way down. Therefore it would not “excite” CO2 on its way out. Is this assumption correct?”
Yes. Only you got the “long” wrong – the longwave part of the spectrum we usually talk about here is the Longwave Infrared that is absorbed by CO2 and to a larger extent by water vapour, > 1 mikrometer. Visible light has shorter wavelengths, around 350nm IIRC.
“Does such long(?)-wave radiation warm the atmosphere at all, as it passes through?”
No, not in a significant way, as it is not absorbed.
“If it does, would not the albedo-effect increase the warming of the atmosphere, because the light would warm on its way in, and also on its way out?
If this was true then, even as expanded snow-cover reflected a lot of heat back into outer space, we might see some slight warming of the troposphere. This might lead to the false impression things were getting warmer, even as we lost a lot of heat to outer space.
Are Oxygen and Nitrogen warmed at all, when sunlight passes through them?”
No interaction between visible light and O2 or N2, otherwise air wouldn’t be transparent for visible light. So visible light that is reflected e.g. by snow will go outwards. There might be refraction by water droplets, so clouds will diffuse visible light. In the absence of clouds, the light reflected by snow (or white roofs, or any part of the surface) will just radiate into space without warming anything significantly.

Norway has already given lots of money during many years to the Soviet’s to put filters on them large factories up in Nickel ….they never used it to filter the smoke anyway….the whole area was black for kilometers after kilometers.
Dont know how it is at the moment…. but back then you could see when you crossed the border to Soviet-land.
Free country; Clean.
Communist land; Dirty.

Trends aside for the moment, this past winter is reaching for the snowfalls not seen since the winter of 1977-78 (as has been well covered). What do this year and the winter of 1977-78 have in common? An El Nino combined with a near-neutral to negative PDO index. That notable winter was the last time this combination happened.
Just as the causes of the PDO’s behavior is not well understood, I am of the opinion that it’s teleconnections are poorly understood, as well. (no surprise, it is a 60 year cycle and we have measured one half of one cycle via global coverage by satellite…and there is no guarantee that this particular cycle is representative of the norm as variability exists in the cycles themselves)
PDO index by month: http://jisao.washington.edu/pdo/PDO.latest
PDO index history plot here (only through Sept 2009): http://jisao.washington.edu/pdo/
another plot…a little experimental: http://www.esr.org/~gunn/pdo/pdo_fig1.png

Leif,
While the trend is slightly upwards, there has been no statistically significant trend in weekly snow cover over the last 20 years. Winter maximums have increased significantly while summer minimums have stayed relatively constant.
http://wattsupwiththat.files.wordpress.com/2010/02/snow_response1.png
It has been claimed repeatedly in the press that snow cover is declining, but the evidence does not support that over the last two decades. A Google search of snow cover decline turns up over one million hits.
What is your point? Do you think that winter snow cover has not been increasing and is not at or near a record maximum?

Now Steve, I can see this is going to get interesting.

Steve Goddard (08:18:41)
There is nothing wrong with that. Provided you make it explicit what you have done, and acknowledge that by selecting the start point, you inflate the risk of a type I error. The post, as it currently reads, is deceptive. I am not implying that this is your intent. Plotting the entire dataset would be a good idea to clarify matters.

@ Tom P (08:01:37)
Tom P, that doesn’t add anything to the conversation, and is actually insulting.
Reminds of the comments when I used to read RealClimate.

“Earlier changes in summer snow extent were likely due primarily to soot – not CO2.”
If Zender is correct, yes. And what is the CAUSE of all that soot, accord to Zender? From the abstract:
“Applying biomass burning BC emission inventories for a strong (1998) and weak (2001) boreal fire year, we estimate global annual mean BC/snow surface radiative forcing from all sources (fossil fuel, biofuel, and biomass burning) of +0.054 (0.007–0.13) and +0.049 (0.007–0.12) W m−2, respectively. Snow forcing from only fossil fuel + biofuel sources is +0.043 W m−2 (forcing from only fossil fuels is +0.033 W m−2), suggesting that the anthropogenic contribution to total forcing is at least 80%.”
At least 80% of the soot is caused by BURNING FOSSIL AND BIOFUELS. So his theory is very interesting, and I hope it holds up, since it suggests the Arctic ice could rebound much more quickly if we took corrective action. But that corrctive action continues to be drastically reducing burning carbon compounds for energy.

Caleb (07:47:41) DirkH (08:15:05) ‘sun rays and molecules’
Figure 2 in the following may be helpful:
http://www.wag.caltech.edu/home/jang/genchem/infrared.htm

Steve, points #1 and 2# are great, but you need a point #3:
3. Because warmer air holds more moisture, it can be too cold for snow. Antarctica, very example, is in many places too cold for snow. Warmer conditions may increase snow, if they make it warmer but not too warm for snow.

Steve,
You got your data from Rutgers University Global Snow Lab.
Have you taken the time to examine their snow cover anomaly chart? Its well done, and tells a bit of a different story:
http://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=0&ui_region=nhland&ui_month=1
Similarly, just winter extent:
http://climate.rutgers.edu/snowcover/chart_seasonal.php?ui_set=nhland&ui_season=1
As Anthony is fond of saying, another entry for the “weather is not climate” department.

@DirkH
Did we read the same post?
Snow is atmospheric humidity and temperatures below 32°F – or am I wrong?
We have more snow in winters since 1989 now – on the Northern Hemisphere, that’s what the graph suggests and what it feels like – but only this winter in Scotland, not the last 10 or so years.
Are you suggesting that we have more snow because we have the same amount of humidity in the atmosphere but the temperatures dropped considerably so what was rain is now snow? Is there any data on that?
If the temperatures have not dropped and the humidity has not increased then where does the snow come from?
From supercharging?

“John Innes (08:12:49) :
For coal-fired power stations, and perhaps to a lesser extent for other soot-generators, it should be cheaper to reduce the soot emissions than to extract and sequester the CO2 generated and emitted. …
Surely we can work from this as a starting point, and get more bang for our warming reduction buck by reducing soot instead of CO2? …”
Well put. Let’s save people who are now inhaling enough soot to kill a half million people per year instead of worrying about what people 4 generations down the road will do to respond to gradual sea level rise of less than a foot per century.

Leif,
Couple points – 1. its very rare to use an R^2 value in a time series, unless you expect the relationship to be linear or monotonic. 2. Applying an R^2 to a linear fit of an oscillating system also makes no sense whatsoever! Its exactly things like this that cause skeptics to not be taken seriously – you fail in basic statistics, but you expect to be able to understand a complex climate system? Give me a break!

A C Osborn,
Setting a different period as the ‘base’ wouldn’t change the shape of the graph, only the zero-intercept of the data. The result is still the same.

I don’t see the growth represented on second graph on the first one, it looks pretty much constant.
Also, 2010 isn’t quite finished, it just started, so how was calculated 2010 point on second figure? it seems it will look pretty much the same as 2008.
Any way is hard to look for differences on sinusoidal signals, I like better the anomalies graph as in http://moe.met.fsu.edu/snow/ though their record isn’t as long, it only goes down to year 2000

vukcevic (07:36:13) :
Keeps deep frost away from the ground surface. Any farmer will know benefits of the winter snow cover.
Henry chance (08:05:49) :
Snow cover is God’s gift to winter wheat fields. It is so many times better than mere rain fall.
The only advantage to snow versus rain is in cases where slow snowmelt occurs leading to increased percolation resulting in reduced runoff in spring (March, April, May).
Frost actually mellows the ground due to frost heave and aids in spring sowing. It also kills insect eggs and larvae in the soil, and some weeds and weed seeds.
A persistent, deep snow cover winterkills winter annuals (wheat, rapeseed, winter peas, etc.).
So no, we don’t want increased long lived snow cover in the US at least.

Steve Goddard (10:20:59) :
A better R^2 on your second graph of winter snowfall would be to add every point with preceding point and plot as two-year accumulated snowfall. That R^2 should show much better correlation and is still proper statistics if you state the results properly. See stat book for proper title, seems would be “The Two Year Accumulated Winter Snowfall”. Could do it for three-year of more. Might uncover a hidden high-freq component.

@ Sordnay (11:05:01) :
I’m trying to figure out how that is representative of reality. On Feb 12 we had one of the largest winter storms in the southeast in a long time, and it barely registers on that chart, if at all? I mean heck, you can look here:
http://ge.ssec.wisc.edu/modis-today/index.php?satellite=t1&product=true_color&date=2010_02_13_044&overlay_sector=false&overlay_state=true&overlay_coastline=true&sector=USA7&resolution=2000m
And see snow cover (howbeit shortlasting) all the way to north florida, but somehow that doesn’t even register on the chart. I wonder how they calculate ‘added snow cover’ because that chart does not seem indicative of what is on the ground right now in many parts of the South East. Does that cover has to remain on the ground for a week for it to register? Doesn’t seem to jive with the reality to me, at least.

@ Brent Hargreaves (12:04:02) :
It ‘snowed a bit?’ This is the second highest extent in the northern hemisphere on record.

Quote: Steve Goddard (08:42:01) :
1. “I am completely at a loss as to what some people are disputing.”
Reply: Someone – skilled in bamboozle propaganda techniques – is purposely directing attention away from undisputed facts that would embarrass NASA and/or Hansen.
2. “We have been told over and over again since Hansen spoke to Congress in 1989, that winter snow is declining and that winter storms are moving north.”
Reply: That is exactly what the propaganda artist seeks to hide.
3. “Clearly that is not happening, quite the opposite.”
You are exactly right.
Since that fact can’t be disputed, a talented propaganda artist might direct attention to R^2, 4/3(pi)R^2, PV = nRT, or anything else to bamboozle the audience.
Thanks, Steve Goddard, for this post.
A least one of your critics is more talented in propaganda than in science.
With kind regards,
Oliver K. Manuel

vukcevic (11:42:13) :That Iphone-Sun it is undoubtely an “electric sun”, even Prof.Leif will agree.☺

…not to mention that Birkeland current in the Andromeda Nasa picture.

Steve Goddard:
Is the Arctic Sea Ice anomaly graph at the following link actually saying the same thing that you’re saying about the snow? –
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg
If so, or not, could you help me understand how your graph and the one at this link fit together. TIA

Zeke Hausfather (11:30:43) :
“Perhaps a cherry-pick-proof graph would help clarify this morass.
Here is the trend to present for every week since 1966 for each season.
http://i81.photobucket.com/albums/j237/hausfath/Picture41”
Great graph. If there is more snow in the Winter and Fall, and less in the Spring and Summer, doesn’t that imply a shifting of the seasons, towards earlier Winters?

Brent Hargreaves: “It has snowed a little, so what?. ”
The issue is that the Team is claiming it has snowed a lot less. Thats a lie.

Karl B. (09:05:32) Tom P is an RC mercenary. I’ve seen him at CA and this site taking pot shots.

John A (12:21:26) :
“I’m sorry Steve Goddard, but I think that the conclusion is largely cherry-picked from the time series and the trend is likely to be spurious. Yes 2010 appears to be a large extension of winter snowfall, but its one season.
As Leif points out, the low R2 of the points says that most of the apparent trend is scatter and not significant. …”

Has anybody bothered to see what the published literature actually says about snowfall predictions?
I haven’t had time to get into this topic, but the one paper I have on hand is observational, not modeling. Changnon, Changnon and Karl, 2006.
They observed maybe an *increase* in snowstorms vs time in the US, over the entire last century, but the data is really really noisy.
Broken down by region, it’s even noisier.
This backs up what Leif is insisting on, when looking for the strength of the correlation. Snowfall data is very noisy, and you can fool yourself into seeing a trend where there’s just noise.
In that context, I’m not sure if anything would surprise me, out of a single winter. Snowfall is truly weather.

So the logic is that with a slight larger area covered in the summer and more so in the winter is due to soot for the summer cover, but only for the summer cover and only back in the day when the summer cover wasn’t as wide as today.
Come again?

Steve Goddard (08:42:01) :
“We have been told over and over again since Hansen spoke to Congress in 1989, that winter snow is declining”
Please provide a link to this statement or publication from Hansen. I’m not familiar with it.

HankHenry;
Snow does increase albedo tending to perpetuate cold conditions, but on the other hand it also insulates the ground preventing deep penetrating cold>
Grew up on the farm Hank and your comment gave me an aha! moment. I remember all those years that there wasn’t much snow and so it melted pretty quick and everyone got hopefull for an early planting season. But then it seemed that spring just couldn’t quite get started and winter would just hang on by its finger nails for the longest time. I’m thinking your post is why, but it would be interesting to see if memory is playing tricks on me and compare snow extent to full seeding to see if the correlation is real.

Steve Goddard
You really stirred up a few folks.
When I get back from Colorado in September, I’ll be sure to let you know if my 20 plus years of observation of the snow-pack Around Monarch Pass fits with your increasing snow in NH in the winter. I really hope you are right.
What a great site. I’m sure everybody agrees except maybe Tom P.

Dr. Tim Ball was interviewed on the Tom Sullivan Show yesterday (16 Feb 2010) in regard to Tim’s views on global warming/climate change.
Dr. Ball proposed the anology of the red noise of an individual in a large stadium and the roar (white noise) heard outside the stadium with the IPCC’s conclusion that the individual (CO2) red noise is responsible for the white noise (global warming/climate change).
————————————————————-
Sunspots and Cosmic Radiation
Governments Plan for Warming Based On Corrupt IPCC Science
By Dr. Tim Ball Thursday, February 18, 2010
http://canadafreepress.com/index.php/article/20150
Do Nothing Than The Wrong Thing
The IPCC was deliberately focused on establishing human causes of climate change so it failed to consider major natural causes. Chief among these were changes in the Sun. It was also deliberately directed to proving CO2 and especially human CO2 was the cause of warming and climate change. This became the basis of all government’s energy and environmental policies, which assume warming is the only possibility. A real scientific investigation would establish natural climate variability and mechanisms first, which is further proof of the political exploitation of the issue. It is better to do nothing than do the wrong thing for the wrong reason.

Steve Goddard;
The trend for the last twenty years is obvious. Don’t get confused by charlatans.>
I’m a confirmed skeptic Steve, and I don’t dispute your data for a moment. That said, there is about 10 years of data on AMSU-A. Now 20 years is not enough data for a measure of climate, so the last 10 is even worse…. But, that data still shows a slight upward temperature trend over the last 10 years at sea surface, near surface, and lower atmosphere while snow extent is also rising. How do you reconcile these?

Steven Goddard:
I think your article was great. Maybe a needed a tidbit deeper analysis and style according to some. Here’s a statistical curiosity.
Using your weekly global data, just analyze the period from first week of 1989 forward. The linear trend is basically flat. Assuming y is in sq.km, the upward slope is a positive 39 sq.km per week over that 21 year period. It is then factual that no decrease has occurred since 1988 and all of the decrease in snowfall occurred prior to 1989. During 1967 to 1988 the decrease was a negative 620 sq.km per week over that period. Wow.
That’s new news to me anyway, that the decrease in snowfall many tout and tie to AGW stopped long, long ago and has been a falsehood for two decades now.
(If you want good R^2 for some, annualize the data first. You get the same trend line, but many magnitudes of better R^2. However, I won’t go there, R^2 is meaningless in this context unless the data was supposed to be a dead straight line and you want to guage how close the data is to being linear in fact, then it could have meaning.)

[img]http://s4.hubimg.com/u/2255951_f520.jpg[/img]

You are certain it is soot that is causing the change in summer snow?

davidmhoffer,
My point is that winter snow cover has been extending towards lower latitudes over the last twenty years, which goes against the endless claims that snow cover is decreasing and storms are moving north.
I’m not definitely not trying to predict a long term climatological trend into the future.

Leif: “This is a new Dark Age arising”:
I am astonished you should come to this conclusion based on the supposed (or even real) ignorance of participants at WUWT. Unless people here were 100% science literate, apparently we count as a rising hoard of barbarians. Yet scientists themselves display gross ignorance across disciplines – how’s your microbiology and understanding of PCR and the methods of genetic modification, for example? One does not expect specialists in one scientific feel to be able to address the esoteric and technical aspects of experts in another field. C.P. Snow lived too early – there’s a gulf between scientific disciplines let alone between the science community and non-scientists.
And yet here we find a blog which is engaging non-scientists in some of the most pressing questions created by scientists – and with good reason. The AGW CO2 theory has needed a good dose of skepticism from everyone, because, as has been well documented since Climategate, and was evident even before this — with examples of scientists losing their positions over failing to toe the AGW line — the ‘science’ has been dangerously tainted by the political advocacy of some of its most influential leaders. They have been allowing their science to be used to justify one of the most egregious attempts at grabbing and redistributing wealth from citizens bamboozled by expertise.
I’m not a scientist, I’m a historian of science, and I felt concern when the ‘scientific barbarians’ like Mann decided that they could massage a well documented historical phenomenon – the MWP – out of existence by superimposing various scientific proxies on top of the written record. Barbarism extends in many different directions, and one manifestation is to forget or deliberately obliterate the past for political or propagandistic purposes– and there is no denying that science was used in a propagandistic fashion by Mann. No matter how energetically Gavin is currently trying to rewrite the history of AGW propaganda on the MWP (and his own past proclamations), the fact remains that for nearly 10 years an important historical era and the quiet and professional work of many historians was being ignored and even ridiculed for ‘scientific’ purposes. But historians are evidently among the barbarians whose rising you fear, since we do not share all of your professional understanding. Insulted? You bet!
Incidentally, I am encouraged by seeing here at WUWT and elsewhere the greatest signs of amateur interest in science probably science the end of the era of amateur science at the turn of the last century. And bloggers here are generally justified in being sceptical in tone due to the arrogance and condescension with which their concerns have been treated by Mann, Jones, the IPCC et al in the past. Not a good idea to pour contempt on those you are perhaps trying to impress.

Leif Svalgaard (12:57:36) :
“…This is a new Dark Age arising.”
Leif – you may be more correct than you realise. The Dark Age at around about 450-700AD corresponds to “Bond Event 1”, the last Bond event, when apparently climate related migrations helped cause the fall of the western Roman empire. Bond estimates 1470 +/- 500 years between these cycles, which means we’re about due. (ref: Science v278, p1257)
Re the maximum NH snow extent, one possibly interesting correlation is land temperature vs snow extent (can’t be UAH series since data range needs to be over at least one PDO cycle). Everyone has been arguing about R^2, it might be interesting to see how correlated these variables are. If R^2 is high then we have ourselves a nice little feedback of humidity->snow->albedo correcting for increased solar W/m2 etc.
On the other hand I don’t see how the increasing Antarctic sea ice extent fits with this since sea ice doesn’t equate to snow.

Larry Kirk (16:41:29) :
Could you clarify a bit on that thought of snow’s ability to reflect. Does that have to do with the fact that the thinner a surface is (low optical path length) the less emissivity it has? Read somewhere that emissivity is always stated for a surface of infinite thickness.
Is that the releated factor of snow crystals you speak of or something entirely different?

Please find below an interesting (to me, if no-one else) breakdown of the growth in snow extent for each week of the year, using the full raw data set from the Rutgers snow lab.
This is hugely amateur effort, hacking around with Excel and probably statistically worthless, but it says to me that the eye is drawn to peaks in graphs, and not slopes.
I basically pivotted the data to plot the extent as a function of year for each week, giving me 53 series of data. I then used Excel’s linear trendline function to give me a gradient for each series (ie each week), and an R^2. The results are below.
What is telling is that there is a positive gradient only for weeks 1, 3, 4, 47, 48, 50, 51 and 52. Negative gradients (suggesting a reduction in extent over time) are found for every other week, and significantly steeper than positive gradients. Plot the “Increase per year” / “Week” data below to see what I mean.
My “analysis” (worth what you paid for it) is that the snow extent is falling for most weeks of the year. I have zero idea what implications that has, but I think it contradicts Steve’s interpretation that extent is increasing.
Anyway, source data, methods and results freely disclosed for peer review – I’d be interested in your comments.
Regards,
Dermot
Week,Increase per year,R^2
1,10840,0.00570
2,-15046,0.00790
3,5791.1,0.00140
4,5937.1,0.00140
5,-6092.6,0.00220
6,-37411,0.04000
7,-24899,0.01590
8,-24303,0.02450
9,-35498,0.04950
10,-72719,0.16240
11,-84099,0.19790
12,-66987,0.15870
13,-50607,0.06910
14,-56710,0.09580
15,-53113,0.10290
16,-79549,0.19180
17,-60042,0.11990
18,-75881,0.24170
19,-75959,0.21560
20,-48842,0.09170
21,-87189,0.24530
22,-77784,0.16670
23,-119080,0.33880
24,-106579,0.34560
25,-94858,0.30870
26,-86636,0.32810
27,-100677,0.51870
28,-75222,0.47350
29,-68542,0.48230
30,-61234,0.47860
31,-52238,0.39010
32,-35916,0.38450
33,-33119,0.27900
34,-27393,0.19950
35,-24235,0.14650
36,-9935.9,0.03700
37,-4007.6,0.00240
38,-1610,0.00010
39,-18059,0.00830
40,-35353,0.02590
41,-48776,0.03750
42,-51209,0.02940
43,-28394,0.00950
44,-24769,0.00900
45,-16896,0.00530
46,-16282,0.00600
47,25341,0.01990
48,951.56,0.00002
49,-2583.7,0.00020
50,24562,0.01700
51,39445,0.04160
52,31345,0.03380
53? hmmm…

“over the last two hundred years, snow cover has gone through many phases where it has increased and many where it has shrunk. People who insist on doing a a linear fit or linear analysis across different legs of a cycle, are just not thinking clearly.”
Does the analysis of this data give us insight into any possible causes for these cycles? That seems to be the truly important thing here- I’m sorry if someone has already offered a possible explanation, I must have missed it.
So yeah, why the big dip between 1967 to 1988, as Wayne describes above for instance? Or from another perspective, by looking at the whole data, I can kind of make out a cycle of about a decade in length, a rise for 5 years, then a dip for 5 years. I’ve no idea if this is significant of anything or not. Given the limited data, we obviously can’t say much about any larger cycles that may be occuring.
As you say, we need to get a handle on these cycles. That would presumably come first- before we start beating each other over the head over whether what we are seeing is significant in terms of (A)GW, or not.

While we’ve seen some record snow this winter, we’ve also seen record tropospheric temperatures. Februrary continues on the same track following in the footsteps of a record January. See:
http://discover.itsc.uah.edu/amsutemps/
For the latest. Note especially sea surface (which is NOT ocean temps) up to 25,000 feet or so. Some of us have pointed out that warm temps and more snow go hand in hand in the winter, just as the very cold Antarctic region is also one of the driest regions in terms of precip. I maintain that yes…this has been a snowy winter, and the warmer tropospheric and ocean temps are to thank.

I’m arguing with Tamino about these same issues at his blog (and he’s being a little rude to be perfectly honest).
It is not cherry picking to say that since 1989, snow extent has been increasing. From the graphs at Tamino’s blog, it appears snow extent decreased from 1970 to the mid-90’s and then began increasing until the present. Fitting a single line to all the data does not help anyone understand the variation of snow extent. In fact, centered around the mid-90’s, 15 of 16 snow extents were below the forty year trendline. A second-order polynomial fit would likely result in a higher R^2 value.

Fellow thinkers,
We must be careful not to fall into the trap of using inadequate statistics derived from incomplete data, ignoring other inadequate statistics derived from incomplete data that may (or may not) have a bearing on the subject, because of preconceived ideas.
I quote an apocryphal story, told to me by my father, told to him by his father who got it from his brother who was in the B.E.F. 1914/15.
When the British army first started issuing tin hats (all right chromium/molybdenum steel helmets) in 1915 there was resistance by the higher authorities on the grounds that “Real soldiers have never worn helmets, in their experience”. This ignored the historical evidence and even that some cavalry units (from which many of the senior officers were drawn) wore helmets. Shortly afterwards hospital returns showed a large increase in head wounds being treated. This was cited as evidence that helmets were not only not needed but were dangerous. It was proposed that steel helmets be withdrawn! Further investigation showed that the number of deaths from head wounds had decreased more than the increase in number of treated head wounds, and of those treated the head wounds were in general less severe than before the introduction of the helmets.
Fortunately for many concerned the steel helmets continued to be issued and saved many lives.
The obtaining off complete evidence, and not partial evidence in isolation, negated possible catastrophic effects. Now where have I heard something similar? Perhaps the proposal to destroy the worlds economy for a religious and preconceived idea.
p.s. It was indeed fortunate for me, as my grandfather was invalided home in 1917 with a head wound, finally released from hospital in 1919, although much of the time was due to re-constructive and plastic surgery.

Steve – Zender did NOT claim that 80% of the soot was due to burning of fossil and biofuels. Read it more carefully
“Applying biomass burning BC emission inventories for a strong (1998) and weak (2001) boreal fire year, we estimate global annual mean BC/snow surface radiative forcing from all sources (fossil fuel, biofuel, and biomass burning) of +0.054 (0.007–0.13) and +0.049 (0.007–0.12) W m−2, respectively. Snow forcing from only fossil fuel + biofuel sources is +0.043 W m−2 (forcing from only fossil fuels is +0.033 W m−2), suggesting that the anthropogenic contribution to total forcing is at least 80%.”
If I read this right this is saying that if you could somehow eliminate the soot due to biomass burning (forest fires and the like), then the remaining carbon generated by fuel burning would cause 80% of the warming. But that isn’t the same as saying that 80% of the soot is due to these sources as the warming effect is non-linear. In other words snow only has to be slightly dirty to cause significant warning and making it twice as dirty probably wont double the effect.
The non-linearity makes the way in which the results are stated deceptive. I suspect that if you analysed the warming contribution of soot from biomass burning in the same way you would find that it too could be said to be `responsible for 80% of the warming’ – maybe more! If so then that would mean cutting all the soot contribution from fuels would only diminish the warming by 20%.
He has presented his results in a rather strange way which I don’t think is very informative. What you would want to know is the marginal impact of mans contribution to the underlying situation, and that isn’t the number he’s chosen to give us.

Steve Goddard (18:46:03) :
Ah, you found something.
So they say the models do a lousy job with snow cover, they don’t show any (model) trend over the 20th C, but a decreasing trend over the 21st C.
You should also discuss this one (Brown, 2009), which looks to be a newer and more detailed study.
http://ams.allenpress.com/archive/1520-0442/22/8/pdf/i1520-0442-22-8-2124.pdf
As well as the observations, as discussed in Changnon et al, and whatever all the IPCC AR4 had to say about the topic (both observations and projections).
You wouldn’t want to be accused of cherry-picking by not giving the whole context of the literature, after all.

Steve Goddard (18:46:03) :
Why are all these models unable to show any increase in snow, decrease in temps, increase in rainfall, etc?
I am wanting to call the computer banks they use Deep Gloom.

Jay,
It is fairly obvious from your comments that you didn’t bother to read the article.

It is quite clear that climate is neither linear nor a second order polynomial, given that the oceans are neither evaporated nor frozen after billions of years – which would be the necessary consequence.
People can argue endlessly about lies, damn lies and statistics, but sometimes they just need to trust their own eyes.
http://wattsupwiththat.files.wordpress.com/2010/02/dec-feb_snow_ext.png
Starting in 2001, 8 out of 10 years are above 45 million km2. Prior to that, 8 out of 11 years were below 45 million km2. The current year is the second highest on record. Enough with the statistics games, please.

Steve Goddard (20:47:37) :
“just need to trust their own eyes.”
For them to do that, you need to show the entire data set. You can start your trend at 1989 if you really want to, but show the entire data set so people can judge the thing in context – are these trends, or just noise?
Just like with temperature: you could draw a trendline in global temperature up from 1996 to 1998, and then another one down from 1998 to 2000. They’d be pretty impressively steep lines, but would it mean anything?

carrot,
We have been bombarded with disappearing winter snow stories for years, and if you have been paying attention you should know that.
A CU professor predicted the demise of Colorado skiing in the middle of a record snow year two years ago. The Met Office predicted the demise of snow in England 10 years ago. RFK predicted the demise of snow in Washington DC two years ago. I just pointed you to an article which showed all IPCC GCMs predicting the demise of winter snow.

Typo. Apologies to all. Should be:
snow=25320 + 22303*SIN[-5.29 + 2*PHI*(week of year)/52]
This is just a curve that symmetrically mimics the earth about the sun. You can get a better fit with extra frequencies, but that just makes it hard to understand and nothing meaningful changes.
I don’t know how to paste the chart of residuals into these comments, but it is easy enough to generate in excel. If you look at the entire period from 1966 there is just no visual pattern of structual change. Sometimes the residuals are bigger sometimes smaller. On the winter side they are smallest around 1989, and largest around 1977-78 and the last couple of years.
Some years there is more so, some less. The year to year variation is entirely within statistical (and visual) norms.

Don Shaw (20:27:13) :
Good find. Keep digging, people. Context is important here: was everybody saying the same thing? Or are the predictions a contradictory and confused mixture? One complication:
“• Increased heavy precipitation
• Less winter precipitation falling as snow and more as rain”
If you combine these two, you could still on net get more snow…
I honestly had no idea what the predictions/statements were on this matter, but I can easily imagine its something the climate models would have trouble with. It’s known that regional precipitation projections need some improvement.
“Also this seems to contradict recent claims by the NYT and others who claimed that scientists predicted the increased snow in the North East we recently experienced.”
First, it’s simply incorrect for anybody to say they used understanding of climate to predict one freak winter. Weather is weather, climate is climate. If they said, “x is consistent with expectations”, that’s fine. Did the articles you read cite any papers? That could add to the pile. I think the Changnon paper shows some sort of increased snowfall trend for the US northeast, though I don’t know if it was significant.
That’s the other problem here – One freak snow season doesn’t prove or disprove any climate projection. And given the high variability in snow data, Goddard’s trend will continue to be questioned.

Yeah Willis! Cutting to the chase as always. Now we have some clarity on the question of the shrinking or swelling winter snow extent, no so-called ‘cherry picking’ of dates involved.

One thing that no one has mentioned would be to compute the area under the curves from minimum to minimum for each year. The time x area should give an interesting look at how much the albedo changes. Any trend in peak levels or minimum levels strike me as being less valuable than the product of the time and the total snow surface available to reflect light.
A cycle with a tall but relatively sharp peak might have less actual effective change in albedo than a shorter but fatter cycle, as the latter would have snow present for a longer period of time.
If you really wanted to get fancy you could compute the days of sunlight for each day of the cycle and also compensate for the changing length of days. A given square area of snow during late December would reflect significantly less energy than the same area during March or April due to the longer day.
Larry

carrot,
Maybe this graphic will make it more clear for you.
https://spreadsheets.google.com/oimg?key=0AnKz9p_7fMvBdHY1dGdwZXdCRVBfekVzQ0FZVENPQVE&oid=1&v=1266558324736

carrot eater (13:23:10) :
It’s pretty clear the problems with relying only on published works.
Raw data is better.
But you want to distract from that. And true to that form, you used the word maybe. Maybe, could, if, the infamous words of a troll.
“you can fool yourself”
I think yes, you could fool yourself more easily than most other people carrot.
And I see you attacked Steven Goddard. You people never quit.

Steve Goddard (16:09:58) :
A lucid defense.
Good on ya!

carrot eater (17:24:07) :
By the way, I’m still looking for any signs that Hansen or anybody else was proclaiming that winter snow extent was decreasing over the US. Still haven’t found it
Keep looking for that Hansen quote, keep looking. Knock yourself out carrot.
Maybe you could link your search to global warming somehow and get some funding for it: you know, join that party! Or are you already in it?

carrot eater,
There is nothing simple about summer snow melt. People who have studied the problem (like Hansen) thank that soot is a primary factor. Zander says up to 90%.
I flew over Greenland during late summer 2007 (the big melt year) and the snow/ice along the western side was absolutely filthy. perhaps from forest fires in Canada.

carrot eater (22:32:56) :
A couple modeling papers
============================================
Why?

carrot eater (22:32:56) :
the relevant sections of the IPCC
================================================
Have you heard about the problems with the IPCC report?
Surely you must have.

Steve Goddard (22:38:19) :
Whether it’s more soot or more warmth, one would expect less snow either way. At least until soot decreases. To me, that makes it easier to figure out than winter, where I can’t reason which way the trend would be. That there isn’t uniform warming spatially in the winter just adds to that mess.

carrot, why don’t you try to write you own paper. Your line of what is expected is your own. You don’t seem to be following what Steve Goddard is saying. I don’t know if it is intentional, unintentional, or what.
There may be other places for you to find people who you don’t have to try to steer toward what you want them to be like.

” Steve Goddard (21:43:56) :
Robert,
Do snow extent maximums occur in the summer, or in the winter?
The graph is clearly marked as “Winter Snow Extent.”
Did you bother to read the article before posting?”
Steve, did you forget that you claimed: “Summer snow cover declined significantly (from the 1970s ice age scare) during the 1980s, but minimums have not changed much since then. As you can see in the graph below, the overall annual trend since 1989 has been slightly upwards.”
Maybe you should read the article you wrote.

aMINO aCIDS iN mETEORITES (23:13:29) :
Of course, Goddard will write whatever he wants. I’m only suggesting a wide scope, as I think it’d be filling a need. He can ignore my opinion. But you might note that he said he was starting with a modeling paper, so I don’t think we differ that much on the idea of whether to look at a modeling paper….
“why would it matter what the IPCC thinks?”
When a lot of people have been saying “it’s snowing a lot this winter, so therefore the IPCC and all the warmists must be wrong”, you don’t think it worthwhile to actually see what the report or the literature says on the matter? Myself, I don’t think a single winter is meaningful either which way; weather is weather, and one year is not a trend, but Goddard sees a trend since 1989. So let’s see what comes of it.

Carrot Eater said:
“A second-order polynomial fit would likely result in a higher R^2 value.”
The game is not to increase your R^2 by increasing the order of the polynomial. That’s generally a horrible idea.
—
Here’s what I’m trying to say…you fit linear regessions to data you think is linear. Looking at winter snow extent, it’s pretty clear to me, it’s not linear…it’s got a cuve to it. Therefore, fitting a single line to all the data doesn’t make a lot of sense.

Steve
Your last sentence:
“Earlier changes in summer snow extent were likely due primarily to soot – not CO2.”
Is this Hansen’s statement or yours? It goes unquestioned. We dont need to be hypnotised by AGW bluster from Hansen or anyone else – ascribing snow trends or anything else in as complex a system as climate, to a single factor, e.g. soot, is certain to be false. Soot in particular is an irrelevant red herring, AGWers are grasping at straws.

Another masterful analysis by Steve “Pixel Counter” Goddard. Using Excel and 21 years worth of data to contradict 100 years of science – and in 500 words or less….impressive!
The “skeptic” community has made many valid observations and critiques of climate science, but allowing folks like Steve Goddard to speak for the community at large illegitimizes potentially useful insights contributed by others.
My advice to everyone here: do not visit this website for science. Peer-reviewed literature is where this debate should be happening, not the blogosphere.

“Why Is Winter Snow Extent Interesting?”
Guest post by Steven Goddard
Well it seems we have several answers to the question and many questions about the answers and many questions that never got answers. I never knew that there was so much interest in winter snow extent graphs.
I’m just a little confused though. It sure seemed that more are more interested in the math of the graphs and not the extent of the snow.
Perhaps those who know about snow and ice and R2 (whatever it is) will put together another article someday that addresses the connection between annual snow and ice extents so the minutia mob stay in the closet.
Somehow I doubt that Plato put up with “R2” minutia and bickering. Wonder how he kept the conversation from such diversions and actually came up with a meaningful discussion and reasonable answer(s) to the question(s).

Phil M,
If you have a specific objection to anything in the article, please state it.
Otherwise, don’t waste other people’s time with your pointless diatribe.

Ronaldo (21:52:24) :
My understanding is that the CO2 molecule absorbs the photon, thus increasing the molecule’s internal (vibrational?) energy and then re-emits a photon of the same energy and thus wavelength but in a random direction. Otherwise we have a perpetual motion machine. Have I got this wrong?>
I bow to Leif and others on this issue who have posted various explanations. I can only advise that the explanations may not be complete as they do not support a practical method to build a photon torpedo. I’ve been told that photon torpedos are science fiction, to which I respond that there is just as much evidence for them as there is for perpetual motion. And AGW.

Quote : Phil M. (05:44:51) :
“My advice to everyone here: do not visit this website for science. Peer-reviewed literature is where this debate should be happening, not the blogosphere.”
Like the IPCC?

A late response to Leif – posted last night but it went missing due to my own error:
Leif:
I went back over previous e-mails and realized belatedly that you were responding to a strain of ’strange’ science in some of the comments that I had not followed closely enough.
However, if you care to look at various episodes in the history of science, such as the belief in phrenology, or the electricity of the body, or the inventor Tesla’s belief in the future of transmitting electrical power through the air or his determination to invent a perpetual motion machine, you will realize that this is nothing new. William Harvey, so famous for determining experimentally the circulation of the blood in the 17th century, also determined experimentally that females of the human and ovine species could become pregnant by gazing lustfully at the males of the species (or in the case of women, portraits of handsome men): no contact required. Harvey in fact was ignoring millenia of scientific wisdom. Aristotle and the Greeks realized that a “mingling of the fluids” was needed for conception to occur.
There is no dark age of science or civilization arising from the eccentrics amongst us: a dark age may arise, however, from the willful distortion of the scientific process for monetary and political ends. This happened under the Nazi regime. Unfortunately the lessons of history are being forgotten, as evidently the IPCC and other bodies believe the ends justifies the means – and the ends cannot be achieved without packaging propaganda as science.

Phil M. (05:44:51)
“My advice to everyone here: do not visit this website for science. Peer-reviewed literature is where this debate should be happening, not the blogosphere.”
This thread by Steve Goddard has attracted a lot of criticism from (apparently) AGWers for stating a rather simple fact: snow extent is increasing, in direct contradiction of general circulation models which predict global warming. The very simplicity of the statement appears to be offensive to some who perhaps need their science to be more complex and opaque.
It has exposed a raw nerve for a clear reason: the global climate is cooling. There are a number of stark and inescapable implications of this:
1) The AGW body of theory is a total failure;
2) Every “scientist”, however many peers they may be able to lay claim to, who has embraced AGW, is a failed scientist: their instincts and methodology have proved wrong.
3) Every scientist who, having looked at the evidence, has instinctively decided that global warming is false and un-grounded, for whatever combination of reasons, has been vindicated as a true scientist. This includes a fair proportion of regular posters on this site, several of whom are climate scientists who have been removed from research positions unfairly by the AGW inquisition exposed in the CRU emails.
It is one thing to be a technician; it is another to be a scientist. If you are a technician, you can have a powerful grasp of the workings of a scientific methodology and body of theory in a particular discipline. You might be a capable mathematician or programmer, but your world is essentially one of methodology. A scientist by contrast goes a little further than methodology, and thinks beyond one particular corner of a discipline or subject. Shocking as it might sound, a scientist requires an accurate intuition, an ability to “sense” the likely relative significance of a range of factors in a complex system for example. (Sound methodology is necessary for good science but not sufficient for good science.)
As the climate continues to cool, the peer-reviewed literature on AGW will be shown for what it is – the self-interested output of professional politicians dressed up as scientists, weaving technical language to construct inductive arguments supporting a pre-decided outcome – indefinite global warming. Such theories have their own internal logic and sense of rightness, but being inductive, are held up by a series of assumptions that represent a fragile and flimsy foundation. Holding such views shows ignorance and contempt for the totatity of climate record extending all the way back to the Cambrian era, with narrative confined to only climate history in the last 1 or 2 centuries or decades.
Peer reviewed literature is where the politics is happening. Climate science that reflects reality is more likely to be found here.