From the University of Washington
From research stations drifting on ice floes to high-tech aircraft radar, scientists have been tracking the depth of snow that accumulates on Arctic sea ice for almost a century. Now that people are more concerned than ever about what is happening at the poles, research led by the University of Washington and NASA confirms that snow has thinned significantly in the Arctic, particularly on sea ice in western waters near Alaska.
A new study, accepted for publication in the Journal of Geophysical Research: Oceans, a publication of the American Geophysical Union, combines data collected by ice buoys and NASA aircraft with historic data from ice floes staffed by Soviet scientists from the late 1950s through the early 1990s to track changes over decades.
Historically, Soviets on drifting sea ice used meter sticks and handwritten logs to record snow depth. Today, researchers on the ground use an automated probe similar to a ski pole to verify the accuracy of airborne measurements.
“When you stab it into the ground, the basket move up, and it records the distance between the magnet and the end of the probe,” said first author Melinda Webster, a UW graduate student in oceanography. “You can take a lot of measurements very quickly. It’s a pretty big difference from the Soviet field stations.”
Webster verified the accuracy of airborne data taken during a March 15, 2012 NASA flight over the sea ice near Barrow, Alaska. The following day Webster followed the same track in minus 30-degree temperatures while stabbing through the snow every two to three steps.
The authors compared data from NASA airborne surveys, collected between 2009 and 2013, with U.S. Army Corps of Engineers buoys frozen into the sea ice, and earlier data from Soviet drifting ice stations in 1937 and from 1954 through 1991. Results showed that snowpack has thinned from 14 inches to 9 inches (35 cm to 22 cm) in the western Arctic, and from 13 inches to 6 inches (33 cm to 14.5 cm) in the Beaufort and Chukchi seas, west and north of Alaska.
That’s a decline in the western Arctic of about a third, and snowpack in the Beaufort and Chukchi seas less than half as thick in spring in recent years compared to the average Soviet-era records for that time of year.
“Knowing exactly the error between the airborne and the ground measurements, we’re able to say with confidence, Yes, the snow is decreasing in the Beaufort and Chukchi seas,” said co-author Ignatius Rigor, an oceanographer at the UW’s Applied Physics Laboratory.
The authors speculate the reason for the thinner snow, especially in the Beaufort and Chukchi seas, may be that the surface freeze-up is happening later in the fall so the year’s heaviest snowfalls, in September and October, mostly fall into the open ocean.
What thinner snow will mean for the ice is not certain. Deeper snow actually shields ice from cold air, so a thinner blanket may allow the ice to grow thicker during the winter. On the other hand, thinner snow cover may allow the ice to melt earlier in the springtime.
Thinner snow has other effects, Webster said, for animals that use the snow to make dens, and for low-light microscopic plants that grow underneath the sea ice and form the base of the Arctic food web.
The new results support a 15-year-old UW-led study in which Russian and American scientists first analyzed the historic Arctic Ocean snow measurements. That paper detected a slight decline in spring snow depth that the authors believed, even then, was due to a shorter ice-covered season.
“This confirms and extends the results of that earlier work, showing that we continue to see thinning snow on the Arctic sea ice,” said Rigor, who was also a co-author on the earlier paper.
The recent fieldwork was part of NASA’s Operation IceBridge program, which is using aircraft to track changes while NASA prepares to launch a new ice-monitoring satellite in 2017. The team conducted research flights in spring 2012 as part of a larger program to monitor changes in the Arctic.
The research was supported by NASA and the U.S. Interagency Arctic Buoy Program. Co-authors are Son Nghiem at NASA’s Jet Propulsion Laboratory, Nathan Kurtz at NASA’s Goddard Space Flight Center, Sinead Farrell at the University of Maryland, Don Perovich at the federal Cold Regions Research and Engineering Laboratory and Matthew Sturm at the University of Alaska Fairbanks.
Two people have already figured out why there is less snow but no one has acknowledged either one, so I will give it a try. The problem with trying to figure why there is less snow from the article is because the iteration line in the chart is incorrectly drawn. It is against the rules of math to draw a linear line through data with break points. I have made this point several times over the past 7 years that I have been in WUWT, mostly as a lurker, but I do participate to some extent.
The chart does show a 60 year cycle with the negative (cooling) phase showing up first then the switch to the positive (warming) phase then a portion of the switch back to the negative (cooling) phase. A tip of the hat to the two who took enough time to study the author’s data before typing a reply. And one of the two correctly identified the proper natural cycle. An additional two people guessed at the proper cycle among three candidates.
To Edward Richardson:
I may not quite understand your question but if you will provide a bit more information, I will be happy to try to answer your question.
Edward Richardson says:
Can you tell me which biological organism in the past couple of billion years had the capability to drill down through four or five thousand feet of rock to extract hydrocarbons? Please verify that this ability is not “unprecedented” or “unusual”
Edward, I must admit that you’ve lost me there. The post was about climate parameters, not “ability”.
My first paragraph established my premise:
“I don’t understand why you keep avoiding the null hypothesis. That is directly connected with natural variability. There is nothing being observed today that is either unprecedented, or unusual. All current climate parameters were exceeded in the past. That was also natural variability, since human emissions were not a factor.”
I am beginning to think you don’t understand what the null hypothesis is.
dbstealey
August 13, 2014 at 4:01 pm
says:
‘Tom J says:
Maybe there’s a precise ‘stab’ measurement. Perhaps it’s in fractions: … I have little doubt, … that their good right arm … precisely and equally stabs that “automated probe” into that snow with no measurable variation whatsoever, stab, after stab, after stab, after…
‘They use a probe with a sliding collet that can be calibrated for a particular depth. That gives it stab-ility.☺’
I salute you sir. ‘Stab-ility.’ That gave me a good chuckle. I still wonder about the accuracy though. The photo I saw of the researcher (bureaucrat?) getting ready to stab that ski pole like device into the snow shows him/her (hard to tell when they’re all bundled up) holding it up at an angle and ready to thrust it down. If they’re doing that repeatedly I have little doubt that the angle’s gonna’ vary and, especially dependent on the diameter of the collet, that’s going to affect the depth it penetrates and thus the measurement. Particularly as he/she gets tired and sloppy. To be accurate that pole would have to be thrust down while it’s completely vertical and I doubt it ever is. These people would never be permitted to work as mechanics or crew on a race car team.
dbstealey says:
August 13, 2014 at 6:07 pm
………”I am beginning to think you don’t understand what the null hypothesis is.”
=============
I know I (still) don’t,… can you explain it in terms an 8 year old might understand ?
Or might that make me the “null”, when explaining the hypothesis I don’t understand 🙂
I spent a number of years involved with a winter automobile test site in northern Michigan. There were two snow seasons there each winter. In the early winter, we would get great amounts of lake effect snow from the near by Lake Superior. Sometime mid winter, Whitefish Bay would freeze over, and the lake effect snow would significantly diminish. In other words, the more ice, the less snow. This was obviously a local situation but proves the point that more information about the local conditions is necessary before making broad generalizations.
To Edward Richardson,
Most hydrocarbons do not get fossilized but a re recycled. Those that become fossilized are mostly released by faults, volcanic activity, and tectonic motion in general. Hydrocarbons were discovered by man when they leaked to the surface or were exposed by erosion.
Mans ability to exploit an oil reservoir is about 20% maximum. Erosion is more thorough at releasing fossil hydrocarbons. A prime example are the Athabasca tar sands in Canada that had the overburden removed by glacial erosion. Another case is the giant heavy oil seep in lake Maracaibo in venezuela. hope this helps.
For many, many, many years the ice has been moving one way. The science is to know when it reverses.
Think about it……
http://www.glerl.noaa.gov/pr/pr_images/glacier.jpg
Well maybe Mosher should have done so, then.
“Tim Ball says:
August 13, 2014 at 10:06 am
A major factor in the final snow level is the amount and direction of the wind. It not only determines the distribution as it falls but also redistributes the snow after it falls. You can also have a phenomenon called scouring in which the wind blowing the snow across the surface can remove previous snowfall layers. This becomes particular corrosive after the snow forms larger granules, firn during the transition to ice.”
Annual precipitation is around 3″. As noted, wind moves the snow all over, and some of us swear the friction just wears it out. It just does not snow much at -35F. Roads are built elevated above the terrain, and the wind keeps them bare, but the snow is quite deep along the shoulders.
Steven Mosher says:
August 13, 2014 at 9:38 am
________________________
G 2 H*ll Mosher ! You are the prime example of a warmist a-hole. Nothing – NOTHING – you have predicted has come to reality. Your pretentious arrogant comments now appear silly and desperate…
Hi u.k.(us),
The Null Hypothesis is the statistical hypothesis that states that there are no differences between observed and expected data.
That’s the definition I got from a texbook, and it’s the one I’ve been using. But it takes a while to sink in. An 8-year old wouldn’t understand it. And it isn’t as clear as the following explanation.
Richard Courtney and I were debating the Null Hypothesis a while back with another commentator, and I saved his comment because it was more lucid than the definition I had been using. Here it is:
The Null Hypothesis says it must be assumed a system has not experienced a change unless there is evidence of a change.
The Null Hypothesis is a fundamental scientific principle and forms the basis of all scientific understanding, investigation and interpretation. Indeed, it is the basic principle of experimental procedure where an input to a system is altered to discern a change: if the system is not observed to respond to the alteration, then it has to be assumed that a change was not caused by the alteration.
In the case of climate science there is a hypothesis that increased greenhouse gases (notably CO2) in the air will increase global temperature. There are good reasons to suppose this hypothesis may be true, but the Null Hypothesis says it must be assumed the GHG changes have no effect unless and until increased GHGs are observed to increase global temperature. That is what the scientific method decrees. It does not matter how certain some people may be that the hypothesis is right, because observation of reality (i.e. empiricism) trumps all opinions.
Please note that the Null Hypothesis is a hypothesis which exists to be falsified by empirical observation. All hypotheses are subject to falsification. It is a rejection of the scientific method to assert that one can “choose” any subjective Null Hypothesis one likes. There is only one Null Hypothesis: i.e. it has to be assumed that a system has not changed, unless it is observed that the system has changed. If it has, that falsified the hypothesis.
However, deciding a method which would discern a change may require a detailed statistical specification. In the case of global climate, if no unprecedented climate behaviours are observed, then the Null Hypothesis decrees that the climate system has not changed. The Null Hypothesis has not been falsified.
Importantly, an effect may be real but not overcome the Null Hypothesis, because it is too trivial for the effect to be observable. Human activities have some effect on global temperature for several reasons. An example of an anthropogenic effect on global temperature is the urban heat island (UHI). Cities are warmer than the land around them, so cities cause some warming. But the temperature rise from cities is too small to be detected when averaged over the entire surface of the planet, although this global warming from cities can be estimated by measuring the warming of all cities and their areas.
Clearly, the Null Hypothesis decrees that UHI is not observed to be affecting global temperature, although there are good reasons to think UHI has some effect. Similarly, it is very probable that AGW from GHG emissions is too trivial to have observable effects.
The feedbacks in the climate system are negative and, therefore, any effect of increased CO2 will probably be too small to discern because natural climate variability is much, much larger. This concurs with the empirically determined values of low climate sensitivity.
Empirical – n.b. not model-derived – determinations indicate climate sensitivity is less than 1.0°C for a doubling of atmospheric CO2 equivalent. This is indicated by the studies of Drs. Idso from surface measurements:
http://www.warwickhughes.com/papers/Idso_CR_1998.pdf
and Lindzen & Choi from ERBE satellite data:
http://www.drroyspencer.com/Lindzen-and-Choi-GRL-2009.pdf
and Gregory from balloon radiosonde data:
http://www.friendsofscience.org/assets/documents/OLR&NGF_June2011.pdf
Indeed, because climate sensitivity is less than 1.0°C for a doubling of CO2 equivalent, it is physically impossible for man-made global warming to be large enough to be observed (just as the global warming from UHI is too small to be detected). If something exists, but is too small to be detected, then it only has an abstract existence; it does not have a discernible existence that has effects (observation of the effects would be its detection), and thus the Null Hypothesis would not be falsified.
To date there are no discernible (observable) effects of AGW. Hence, the Null Hypothesis decrees that AGW does not affect global climate to a discernible degree, and the Null Hypothesis has not been falsified. To be falsified there would have to be observable, measurable effects. That is the ONLY scientific conclusion possible at present.
Hope that helps.
You all should appreciate the Mosher comments more. He and Stokes and many others are closet skeptics, or they wouldn’t be here..Filtering through the trained spin requires a certain level of exposure. That is not intended as an insult to anyone. Unfortunately, citations directly correlate to funding of such.
Albeit citations are a fleeting thing, it is all we have.
That graphs shows the decline starting even before 1950. But the warming didn’t start until the mid 70s. Infact, the globe was actually cooling during the 50s and 60s. So if anything, this result should prove the AGW is NOT causing this, and that this is a natural phenomenon.
Steven Mosher says “read climate science. say no and throw up a reason”
—-
Here’s Mr Mosher’s two word rebuttal comment on a previous story last week:
Steven Mosher says:
August 5, 2014 at 4:52 pm
“One site.”
Not only is he rude but he’s a hypocrite. Grow up Steven. Seriously, grow up. Leave the discussions to adults.
Less snow means what, colder climate? Whatever ice there is, wouldn’t it fall on it in September and October anyway? No one here would argue that temperatures haven’t warmed since 1950 so what’s the news here? No one knows what was going on in the artic prior to that. Was there more or less snow in the 1920’s or 30’s? The main argument against CAGW is that sea level rise has been remarkably constant, that extreme weather events is a myth and that the correlation between CO2 and temperature is tenuous. Here I am, a layperson following all of these ‘papers’ and I’ve yet to see one that shows me the money. It’s all speculation built on models.
Steven Mosher or anyone for that matter, explain to me why CO2 caused all the warming since 1950 but the warming at the turn of the 19th century was natural variability. Why were the 1930’s just as warm as now and why did the 60’s and 70’s cool? If you can’t explain the warming during those periods, how can you be so sure about the current warming?
It is the difficulty in making observations in a complex environment where much is not known, You only have a limited perspective and when you make judgments based on that limited perspective you are easily deceived.
But here is where the rubber meets the road; show me the sea rise and the increase in extreme weather events and the rise of temperatures linked to CO2 increases.
looncraz says:
August 13, 2014 at 10:49 am
The question is: What happened in the 90s to change the snowfall or to increase the melt?
====================================================================
The large El Nino at the end of the 1980s that lasted until mid 1995 may have been the start of a warmer flow of water into the Arctic.
Joseph Bastardi says:
August 13, 2014 at 12:54 pm
What next, size of snowflakes?
==========================================
The next study will show how the shape and flavor of snowflakes has been changing since the rise in co2.
I wonder over what period and frequency their measurements were taken. I’ve seen considerable depths of snow some years in my back garden, and other years I’ve seen none. I’ve also seen deep snow and no snow in the same winter period, and deep snow in some areas and no snow in other areas at the same time. Their conclusions don’t state whether the cause is ice and snow melt as opposed to reduced precipitation. If they feel it is melt that has caused the problem then it was interesting to see that their research was done in areas of -30 degrees!
So with rising temperatures we were supposed to get MORE precipitation not less. So perhaps the GHE theory is wrong.
dbstealey
From the article.
“Knowing exactly the error between the airborne and the ground measurements, we’re able to say with confidence, Yes, the snow is decreasing in the Beaufort and Chukchi seas,” said co-author Ignatius Rigor, an oceanographer at the UW’s Applied Physics Laboratory.
And your excellent comments above on testing hypotheses can I add…
It’s a bit more difficult than the above quote would suggests. What is the magnitude of any experimental error? I’d guess there is a significant difference in both techniques. This may go to explain the significant heteroscedasticity in the plot. So all may not be what it seems, and while one could apply weighted regression analysis to address this issue in order to get a statistical model with more robust analysis, it does still suggest that you may have two sub-population in this data – to me it seems clear that the heteroscedasticity is due to the twin-historical datasets. The plot should therefore be coded according to technique, otherwise your just splicing one dataset with another – and we’ve seen that done before. In short, bot sets should be marked differently on the plot (different symbols for the different periods).
dbstealey
…I need to add if there is indeed heteroscedasticity (I think there is) then the p-value supplied is nonsense if they’ve used simple linear regression – they need to use weighted approach.
It is counterintuitive IMO that less sea ice would cause less snowfall. Wouldn’t less ice would expose more unfrozen Arctic Ocean which should provide more moisture to the atmosphere increasing snowfall?
Edward Richardson says:
August 13, 2014 at 5:49 pm …
I rather think the point here is “the capability to drill down through four or five thousand feet of rock…” has had no observable effect on world temperatures once you factor out what you would expect from the null hypothesis of natural variation.
Raw observations tend to verify that this ability has not produced “unprecedented” or “unusual” world climate responses.
Chuck L
Yeah there’s a whole lot of this that doesn’t quite follow or doesn’t quite fit the usual AGW narrative. I always remember being told that that the colder it is then the less likely you are to see large snow accumulations. I don’t know if this is true, I’m guessing all you need is some moisture in the atmosphere and it to be cold enough. In which case the movement of air (and associated weather) needs to be at least looked at. For example, has snowfall increased elsewhere during this same time.