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.
http://www.cnn.com/2014/08/12/opinion/weisman-craters-methane/index.html
http://blogs.dw.de/ice/?p=15369
Snow is precipitation. If snowfall is in decline in an area where it is impossible to look at snowfall history you are left only with making a note in your logs and moving on. Any conclusion regarding snowfall on pack ice is speculation, opinion, and guesswork. What we can conclude is we can conclude nothing about the history of the snowfall until we have a proper history of the region. That is decades away.
This is not opinion – we don’t have enough information to know if this is unusual. It is ok to say “we don’t know”.
Since I’ve been following the study of arctic ice I’ve been impressed by the work these fellows do under difficult and dangerous conditions. Sooner or later we are bound to lose one to a stealthy, well-camouflaged bear. I’ve also been impressed by the -snip- they have to work under. The underlings run risks gathering the facts and hard data, and the -snip- sit in comfort and supply the political slant.
It is interesting that the data they have shows decreasing snow. It springs to my mind that the AMO cycle is roughly 60-70 years, and we may being seeing a side effect of that. Also it should be noted that there weren’t all that many Russian and NATO bases floating around up there, (pretending to do science while in fact spying the dickens out of each other…even back then politics ruled.)
However I’d be more interested to see any bits of data they may have on summer snows in past years, and whether they had as much as we’ve had this year. According to various charts I’ve looked at, freshly fallen snow has the highest albedo, and to have snow blanketing the arctic in July really throws a monkey wrench into all the talk about how the arctic is absorbing more sunshine due to open water, and the claim that this absorbed warmth is over-heating the Arctic Sea and causing the ice to go into a “death spiral.”
I honestly fear the better sea-ice scientists will lose their funding if the arctic starts to behave in a politically incorrect manner, and the sea-ice increases. At the very least the wonderful cameras they have floating around up there will have their plugs pulled. After all, we wouldn’t know it was snowing in July if our lying eyes couldn’t see it. I saved a fine example of such fresh snow on July 27, at the very height of the melt-season, at the start of my post at: http://sunriseswansong.wordpress.com/2014/07/27/arctic-sea-ice-melt-the-death-spirals-debunking/
If the climate system is mostly chaotic and/or unmeasurable in many key components, then it’s inexplicable.
There really aren’t any changes until the 90s. That is the problem with linear trends, they hide the details that make all the difference. The question is: What happened in the 90s to change the snowfall or to increase the melt? As has been mentioned, regional changes require regional answers.
Edward Richardson says:
August 13, 2014 at 10:03 am
The starting point of scientific inquiry, ie the Null Hypothesis, is that nothing out of the ordinary has happened climatically during the 20th & 21st centuries, ie that the same natural variability that has explained climate change for the past 4.56 billion years explains it now.
When sea ice forms in calm conditions then heat can be radiated through the ice allowing the ocean underneath to continue cooling. Any cover or snow on that ice provides a reflective surface that reduces or prevents that radiation to atmosphere / space. In Antarctica snow did not happen at Vanda Station (30 km inland from coast in Dry Valleys) until the sea ice in the Ross Sea broke out. Only then did the air contain enough vapour to form clouds and cause snow. (only once in four months did we get snow falling and that ablated within hours) significant snow was only deposited when clouds touched land or ice.
Any chance they have onsite temperature measurements at time of snowfall?
I have noticed that seldom does it snow at 30 below.
Here next to Great Slave Lake.
Usually we get greater snowfall in warmer winters.
So is the later ice meme plausible?
Or is it cooling, with less open water,less moisture in the air?
This differs form earlier time periods by?
This AGW concept is beginning to resemble CAGW, coulda,woulda,shoulda.
If only we has kept some real weather stations in the Canadian North, in the 1990’s….
Insufficient data is beginning to look like a plan, rather than an unintended consequence.
Until Climatology is flushed out, I expect my first reaction to claims of change, especially unprecedented change, will be cynical to say the least.
When you stab it into the ground, the basket move[s] up, and it records the distance between the magnet and the end of the probe…
————
Warmunist-approved ground stabbers are required to place a few large rocks into the basket prior to making measurements.
Edward Richardson says:
No, natural variability is not the starting point.
According to the null hypothesis it is.
Of course the default position (or starting point as someone tried to simplify for Edward Richardson)is natural climate variability. It’s called common-sense. But we’re not allowed to use any of that when debating with warmists …
At least you have to give credit to the authors of the original article. They state their observations, speculate reasons and consequences (while clearly identifying them as speculative) and stating the uncertainties, all the while refraining from making dire apocalyptic predictions that seem to have become the norm in climate science.
The result of these measurements may or may not have any broader meaning. To me, it just seems that lower snow pack on ice is consistent with the reduced ice area over the last few decades. As the arctic ice rebounds, the snow pack may evolve as well. It’s a matter of curiosity, not economy-shattering policy.
I was curious to find a detailed picture of the “automated probe similar to a ski pole” that, “Today, researchers on the ground use … to verify the accuracy of airborne measurements (of snow thickness).” Alas, I could not. Now, part of the reason I wanted a detailed picture was because I feared it could be used as a dangerous weapon. After all, the use of tools is not often referred to in a violent fashion. We may ‘pound’ a nail, ‘hammer’ a stake, ‘drive’ something into the ground, but I don’t ever recall a stake described as being “stabbed” into the ground. But, perhaps I need not fear. Perhaps Melinda Webster’s anger management issues are under control or perhaps they never existed in the first place. And, in any case, it’s unlikely I’ll be traveling to the Arctic anytime soon.
But, maybe my concerns about violence were unfounded in the first place. Perhaps the word ‘stab’ is a legitimate scientific description. Maybe there’s a precise ‘stab’ measurement. Perhaps it’s in fractions: 1/4 stab which is twice 1/8th of a stab. Perhaps it’s in decimals: 0.01 stab + 0.01 stab = 0.02 stab. I would certainly hope it’s a new state of the art scientific description since it coexists with a sophisticated branch of science that claims to measure millimeter variations in the Earth’s diameter, joule measurements in depths of hundreds of meters in multi-quadrillions of gallons of water, and substances down to parts per trillion.
And, I have little doubt, as that intrepid researcher trudges onward and outward through the snow, that their good right arm (or left arm if they’re left handed) precisely and equally stabs that “automated probe” into that snow with no measurable variation whatsoever, stab, after stab, after stab, after…
stab, after stab, after stab…
Actually, I rather impressed that the authors essentially said we don’t know why the snow is thinning nor the consequences.
From the snows of Kilimanjaroto the snows in the Arctic weather happens and quite often in cycles.
But it’s rotten snow!
Jtom says:
August 13, 2014 at 11:34 am
“Actually, I rather impressed that the authors essentially said we don’t know why the snow is thinning…”
Hmm…. the data starts in the yr 1950 (same yr that CAGWers claim that mans CO2 supposedly started having an effect. What do you want to bet the next paper will have a graph of CO2 from 1950 plotted along with that purported linear snow thickness trend. I see “catastrophe” written all over that graph.
Steven Mosher says:
August 5, 2014 at 4:52 pm
One site.
Here is an example of Mosh’s “Climate Science” at its’ finest.
According to climate “scientist” NASA emeritus Robert Bindschadlerh, all we need to accept human-driven climate change is the following:
“Keeling’s curve and the fact that we know CO2 is going up. We know the physics of if you put CO2 into the atmosphere we know what is going to happen. That is physics. You can’t deny that; you can’t deny the Keeling curve that we’ve been pumping it in there. We know how much fossil fuels we’re taking out of the ground, and we know how much we’re burning and it’s traceable. And all the projections of climate models are becoming observable facts.
That’s all you need. It’s real straightforward.”
Ayup. By gosh and by golly, it’s so simple a caveman could do it.
More of this climate alarmists’ propaganda and faux science here: http://truth-out.org/news/item/25509-nasa-scientist-warns-of-three-to-four-meter-sea-level-rise-by-2200
Tim Ball on wind: I used to live in southern Sasakatchewan where it was a common to say we got the same snow 5 times – once when it first fell, then when it blew away, then when it blew back, then blew away and then back again. Anyone who has lived on the prairies and seen the sculpted wave like snow drifts undulating for miles; and watched the snow turn from white, to glazed ice, to grey, to black – knows of what I speak – dusty snow storms in the spring. Bare ground on the hill tops and flat looking snow several metres deep filling ravines and tree lines. There is a reason Saskatchewan highways are built up above the surrounding farmland. The wind sweeps the snow off.
I would imagine snow depth on the ice would be more a function of surface wind strength than snow fall. The wind blown snow would tend to pile up around ice ridges and end up in leads.
However, as a method of calibration, I expect the process is appropriate.
Note: in general in my experience in the north, the less snow, the thicker the ice. Early snows insulate the ice and keep it thinner. Less snow also provides more light below the ice for plankton and algae.
Its well documented that NH Spring snow fall has been dropping while NH Fall and Winter snow falls have been increasing. All this study shows is that this area of the Arctic is experiencing the same thing in the Spring. I’d be curious to see the Fall and Winter snow levels…
http://climate.rutgers.edu/snowcover/chart_seasonal.php?ui_set=nhland&ui_season=1
Different techniques for collecting the data can be the entire reason for the difference. In addition, the trend was actually pretty flat until around 1980 so it could be the +PDO or +AMO (or both).
john robertson says:
August 13, 2014 at 10:59 am
Any chance they have onsite temperature measurements at time of snowfall?
I have noticed that seldom does it snow at 30 below.
That matches what I was told decades ago in school — colder climates nearer the north pole get less snow. So, less snow on the arctic ice pack could be a sign the climate is cooling, not warming. The assumption that less snow means warmer average temperatures is what you might expect from winter weather patterns in temperate zones like the northern US, which are of course far south of the arctic circle.
@Tim Ball says
“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.”
Across the Greenland Icecap things were pretty featureless (excepting coastal areas where there are mountains and glaciers). On a cloudless day, it was mostly just a vast expanse of white from north to south and from east to west. However, that made it pretty easy to spot blowing surface snow, depressions and gentle hills of snow even from thousands of feet in the air. There were huge ground blizzards, building up snow in some places and removing it in others, just as you point out.
Having lived most of my life on Colorado’s eastern slope, I’m quite familiar with ground blizzards, and I marveled at how vast these areas of blowing snow were across the Greenland Icecap. With so much continuous redistribution of snow going on, I don’t see how anyone could possibly get accurate data about snow depth.
Jimbo,
Please may we have one of your delicious lists on snowfall predictions if you possibly have one at hand?
Jones
will it ever stop? Sea ice on danish site near normal now, below, but higher than past 10 yrs on cryosphere site here
http://arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html
Its like they make up one metric after another to distract people from how wrong they are.. about almost everything. What next, size of snowflakes?