Epic survey finds regional patterns of soot and dirt on North American snow

From the University of Washington

Dark snow Greenland

Dark deposits on icefields in Greenland, which absorb more sunlight and lead to faster glacial melting. Photograph: Henrik Egede Lassen/Alpha Film

Snow is not as white as it looks. Mixed in with the reflective flakes are tiny, dark particles of pollution. University of Washington scientists recently published the first large-scale survey of impurities in North American snow to see whether they might absorb enough sunlight to speed melt rates and influence climate.

The results, published in the Journal of Geophysical Research, show that North American snow away from cities is similar to Arctic snow in many places, with more pollution in the U.S. Great Plains. They also show that agricultural practices, not just smokestacks and tailpipes, may have a big impact on snow purity.

During their almost 10,000-mile trek across North American snowfields, the researchers were particularly interested in the Bakken oil fields of northwest North Dakota.

“With all this oil exploration, diesel trucks and new oil wells, people wondered: Is there a huge amount of air pollution making the snowpack darker?” said lead author Sarah Doherty, a research scientist at the UW’s Joint Institute for the Study of the Atmosphere and Ocean.

What they found was that these activities do appear to be adding extra soot to the snow, but perhaps just as important is the dirt. Disturbance from clearing oil pads, new housing sites and all the extra truck traffic on unpaved roads means dirtier snow. But even away from the oil fields, soil is disturbed by agriculture.

“Our work suggests that land use and farming practices might matter as much as diesel emissions in many parts of the Great Plains,” Doherty said.

Doherty was part of a team of UW atmospheric scientists who spent the winter of 2013 driving across northwestern U.S. states and some Canadian provinces to get a firsthand look at the continent’s snow.

The project involved collecting hundreds of snow samples from 67 sites away from any cities or major roads. The trip took the researchers from Seattle to North Dakota to Churchill, Manitoba. Every few days they melted and filtered the snow in their motel rooms, then back at their UW lab they shone light through a filter to see how much light was blocked, and did chemical analyses to determine what particles were responsible. (Read more about the group’s adventures on the road at http://www.bitly.com/snowsurveymethods)

Their main focus was black carbon, a very light-absorbing particle emitted by burning diesel, coal or wood. Many countries have regulated black carbon because of its effects on air quality and human health, but more recently climate scientists also have become interested because the tiny particles darken the snow and hasten melting. The cleanest samples they collected were from northern Canada, with overall levels of black carbon, or soot, similar to that of Arctic snowpack. The Pacific Northwest and Rocky Mountain states had levels slightly higher. The Great Plains readings were more variable and sometimes two to three or more times higher than in other parts of the country, typically 15 to 70 nanograms of soot per gram of snow.

Doherty previously worked with co-author Stephen Warren, a UW emeritus professor of atmospheric sciences, on a 2006-2010 survey he led of snow in the Arctic. Warren and Doherty also worked with Chinese collaborators in 2010 surveys of snow in northern China, all using the same techniques so the combined results can provide a first-ever global map of snow cleanliness.

Results from China showed rates of pollution tens to hundreds of times greater than in North America, with the highest rate in northeast China of 1,220 nanograms of soot per gram of snow, likely because of industrial activity and other emissions in the Beijing area. But dirt and desert dust also were prevalent in central North China snow.

“For a lot of the central U.S. and north China Great Plains the snow is not very deep. In the U.S., almost the whole area is agricultural fields and in China there is a lot of animal grazing,” Doherty said. “When the wind blows the dirt gets lofted, maybe just 10 feet off the ground, and gets mixed in with the snow.” North Dakota locals refer to the mixture as “snirt.”

The new paper documents how much light is blocked, and at which wavelengths, by filtered snow samples. Other co-authors and snow collectors were research professor Dean Hegg and graduate students Cheng Dang and Rudong Zhang, all in UW atmospheric sciences.

A companion paper by Dang and Hegg involved a chemical analysis of the North American samples to pinpoint exactly which compounds are contained in the snow.

“A lot of the focus in climate models has been on black carbon, because it’s a pollutant and it’s very dark,” Doherty said. “But the snow is darkened by other things as well, like organics, and also by dust and soil that can get in the snowpack.”

In fact, they found that in the Great Plains states up to half of light absorption is due to organic matter, or “brown carbon” from burning fossil fuels and from soil that mixes in with falling snow.

The deposits affect both global and local climates. Pollution on the Himalayan glaciers, for instance, is raising concerns that it will speed melt rates and harm water supplies. For U.S. farmers, changes in the snow’s reflectivity could affect when the spring melt will occur and when meltwater will drain out.

Whether the pollution the researchers found in North Dakota is enough to change snow melt timing will have to be answered by region-specific climate models, Doherty said.

“But first the models have to do a more accurate job of representing the amount of dirt that’s in the snowpack,” she added.

###

The work was funded by the Environmental Protection Agency and the China Scholarship Fund.

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181 thoughts on “Epic survey finds regional patterns of soot and dirt on North American snow

  1. Nonsense. black carbon and soot is a trace material. Plus it’s proven that humans can’t have any impact whatsoever on the climate and that includes snow.
    hehe. sarc off

    • Dear Steve,
      Seems, lately, you never miss an opportunity to mock anyone that considers the “consensus” opinion to be alarmist. As someone who respects your contributions to the climate issue, and that has watched your recent slide into cantankerousness, I am puzzled by this compulsion.
      Do you make these snide asides at the alarmist sites, like Skeptical Science and RealClimate?
      (Not that those sites would allow dissenting opinions.)
      Best,
      Lance Harting
      IUPUI School of Science

      • Lancifer, speaking for my own crankytankerousness, no small amount of it stems from not being able to discuss this issue without several someones characterizing my personal opinions to be alarmist. I usually try to keep my snark strikes tactical and surgical, but sometimes I carpet bomb indiscriminately. I try to justify that as a strategic imperative, but the more honest truth is sometimes I do get genuinely hacked off and lose my temper.

    • Even if the source was human, it couldn’t have a significant effect on anything much. Just governments trying to bring in taxes to clean up the snow

      • sunshinehours1,
        Ah yes, the old “if something has happened naturally in the past, it can only ever naturally” argument.

      • Gates,
        That is a damn good argument, just ask Billy Ockham.
        Unless you have evidence that “this time it’s different”, you are making your usual inane, pointless argument, nitpicking whatever you can.
        No wonder you’ve lost the debate. Why not spend your energy job hunting, instead of making your endless, worthless comments? It could at least be productive.

      • dbstealey ….Brandon Gates has not “lost the debate”…..
        ..
        It seems that you have by resorting to ad-hominem attacks…(i.e. “Why not spend your energy job hunting” )

      • Just interested in expanding my knowledge, that’s all.
        So, how do I get a great job like that, where I can write blog comments instead of doing what I’m paid to do?
        Of course, if you’re being paid to comment, that would explain it.

      • dbstealey,

        Unless you have evidence that “this time it’s different”, you are making your usual inane, pointless argument, nitpicking whatever you can.

        This time the “dust” looks like the same stuff that collects on the inside of the exhaust pipe of an internal combustion engine. A 6th grader with a box of Q-tips, a bottle of xylene, some glass slides and a microscope could figure out the difference between 1 year old Arctic “dust” and 1 million year old Antarctic dust.
        Fortunately the people out there collecting the research samples are a bit past the science fair level.
        Now go on, tell us again how volcanoes are responsible for CO2 rise since 1850. Literature citations if you please.

      • Brandon:
        “In 1992, it was thought that volcanic degassing released something like 100 million tons of CO2 each year. Around the turn of the millennium, this figure was getting closer to 200. The most recent estimate, released this February, comes from a team led by Mike Burton, of the Italian National Institute of Geophysics and Volcanology – and it’s just shy of 600 million tons. It caps a staggering trend: A six-fold increase in just two decades. ”
        http://www.livescience.com/40451-volcanic-co2-levels-are-staggering.html
        I wonder if even 1% of the money thrown away on AGW funding was spent on actually finding out how much CO2 came out of volcanoes what we would find out.

      • sunshinehours1,

        “In 1992, it was thought that volcanic degassing released something like 100 million tons of CO2 each year. Around the turn of the millennium, this figure was getting closer to 200. The most recent estimate, released this February, comes from a team led by Mike Burton, of the Italian National Institute of Geophysics and Volcanology – and it’s just shy of 600 million tons. It caps a staggering trend: A six-fold increase in just two decades. ”
        http://www.livescience.com/40451-volcanic-co2-levels-are-staggering.html

        Mhmm hmmm, is that a six-fold increase in the estimate of output, or a six-fold increase in actual output?

        I wonder if even 1% of the money thrown away on AGW funding was spent on actually finding out how much CO2 came out of volcanoes what we would find out.

        The IPCC has already spent quite a bit of money to tell you that natural carbon fluxes are 35 times higher than anthropogenic ones. That isn’t good enough for you?
        http://www.ipcc.ch/publications_and_data/ar4/wg1/en/fig/figure-7-3-l.png
        If you tally up the numbers, 212 GtC/year from natural sources. That’s 2.12 x 10^11 metric tons of carbon. The article you linked to is talking about 600 million short tons of CO2, which works out to 1.47 x 10^08 metric tons of carbon.
        Which means that the sixfold increase in estimated volcano output brings the grand total up to 0.07% of the sum total of natural sources already identified by the IPCC. They don’t even break it out on the cartoon because that’s basically a rounding error compared to other natural fluxes.
        Compare the shapes of the following curves now. Fossil fuel carbon emissions:
        http://cdiac.ornl.gov/images/global_fossil_carbon_emissions_google_chart.jpg
        Atmospheric CO2 composition:
        http://climexp.knmi.nl/data/ico2_annual.png
        Notice a similarity?

      • Brandon: “Notice a similarity?”
        Your CO2 graph is a actual measurements of CO2 graphed onto proxies for CO2 … correct?
        We know that means very little. We also know temperature goes up and down in the ice cores and then CO2 reacts.
        Yes I know the IPCC has squandered a lot of money lying to us.
        “Scientists” would be fascinated by a 6 fold increase in volcanic CO2. Especially since there is a huge incentive to not look for natural sources of CO2. Imagine if they actually looked.

      • sunshinehours1,

        Your CO2 graph is a actual measurements of CO2 graphed onto proxies for CO2 … correct?

        Correct.

        We know that means very little.

        Why and how?

        We also know temperature goes up and down in the ice cores and then CO2 reacts.

        Those were the findings of Petit et al. (1999) per the plot you posted just above. I’ve got no quibble with that paper.

        “Scientists” would be fascinated by a 6 fold increase in volcanic CO2.

        Quite right they would be. It would indicate something unusual was going on.

        Especially since there is a huge incentive to not look for natural sources of CO2. Imagine if they actually looked.

        They already have looked, and according to the IPCC carbon cycle cartoon I posted previously, natural fluxes are 33 times GREATER than human emissions. How does that demonstrate non-incentive to identify natural sources of CO2? How big does the multiplier need to be for you to be satisfied?

      • Those guys wrote that the oil sands in Alberta would be economically un-viable by 2020. Fools.
        Once I read that and their bowing before the IPCC projections, it was a waste of time article.

      • To joelobryan, you wrote:
        “Those guys wrote that the oil sands in Alberta would be economically un-viable by 2020. Fools.
        Once I read that and their bowing before the IPCC projections, it was a waste of time article.”
        I have a different opinion. The article is not bowing before the IPCC projections. Quite the contrary. It says, without insulting anybody “here are the consequences of the IPCC projections”.
        You don’t like that the oil sands in Alberta would be economically un-viable. Do you think the Canadian government does not know this? Look at the other affected countries.
        So instead of arguing about the IPCC model, the global temperature averages, the anomalies, the pause, the dirty snow etc., the consequences are spelled out for each producing country. I think this will have more impact, at least I hope so.

      • “For U.S. farmers, changes in the snow’s reflectivity could affect when the spring melt will occur and when meltwater will drain out.”

        I have often wondered why northern hemisphere snow extent has increased in the fall and winter since 1967, but declined in spring. The same trend applies to north America. Is this largely down to soot and dirt?
        The NSIDC says:

        Snow cover wields the largest influence during springtime (April to May) in the Northern Hemisphere, when days become longer and the amount of sunshine increases over snow-covered areas. Snow’s high reflectivity helps Earth’s energy balance, because it reflects solar energy back into space, which helps cool the planet.

        • Jimbo:
          Let us assume that the NSIDC is talking about changes in snow cover (and thus changes in albedo) in the spring, as above when snow extent (and thus albedo) appears to have declined only in the spring.
          Blame CO2!

          In the NH summer, EVERYTHING is now growing 12% to 25% faster, longer, and taller and greener, but the reflectivity from that extra growth only slightly changes the total albedo of the NH. Fields are still green, forests still green, grassland still green.
          In the NH fall, leaves are falling and branches exposed and fields are plowed under or harvested just like before CO2 strongly influenced growth, but there is no real change in albedo reflectivity between any time earlier and now.
          In the NH winter, plants and grass are short, bushes and trees are bare, and the snow cover reflectivity is essentially unchanged.
          But in the NH spring, things are growing greener faster and taller earlier than they were in years past. More snow and ice is hidden from the sun earlier than before, and so reflectivity goes down as plants grow faster earlier each spring. Warmer (even by 1/4 of one degree) has little effect that can be measured. But 25% MORE leaves earlier in the season by EVERY bush and tree?

    • I find you contribute less and less to these discussions every time you post. In fact, what you post can hardly be said to contribute to the discussion at all. Drive-by snark does not contribute anything, but it does reflect quite a bit on you, Mosh.

  2. In the Colorado Rockies, the presence of red dust blown in spring dust dust storms from the Four Corners area mixing with spring snow storms over the Rockies is a significant accelerator of snow pack melt.
    I’ve seen it vividly in Denver. When the snow is melting on roof tops, you see these red-tinged lines where the dust is accumulating as the melt water runs through the snow. Increases solar absorption, accelerates melt. Simple.
    The glacial periods show elevated atmospheric dust, likely because a colder earth is a drier earth. Just one more negative feedback in the natural hydrologic cycle that helps regulate global temperatures.

    • “””””…..Doherty was part of a team of UW atmospheric scientists who spent the winter of 2013 driving across northwestern U.S. states and some Canadian provinces to get a firsthand look at the continent’s snow……””””
      Well that was mighty white of her; going on a 10,000 mile junket to spread her auto exhaust soot over everyone else’s snow.
      Snow doesn’t “reflect” it “scatters”. Most of the “light” enters the snow or ice, where much of it is trapped by TIR. It only takes a few hours for the sun to melt the surface and make it transparent.
      What light does then escape from solid / liquid “snow” is scattered into a diffuse Lambertian back scatter.
      It doesn’t take many hours for fresh snow to be turned into a surface with no more “albedo” contribution than ordinary grass or dirt.
      Crevasses in glaciers look blue, because the blue rays are the only ones that can propagate in even the purest of waters for any great distance, and eventually find a facet they can emerge from.
      And the soot which accelerates “melting” is merely aiding and abetting the optical trapping of a lot of radiant energy in the ice that non fresh snow quickly becomes.

      • >>> It doesn’t take many hours for fresh snow to be turned into a surface with no more “albedo” contribution than ordinary grass or dirt.
        Around here it takes often months, until the Sun gets up some 30 degrees from the horizon.

    • The first sentence from that NASA link is this: “Sunlight is the primary driver of Earth’s climate and weather.” Whatever happened to CO2 as the primary driver of climate, because that is what the climate change extremists have been telling me for years?

    • Here’s some data that causes one to re-think how naturally-occurring dust can and does affect albedo:
      http://www.nasa.gov/images/content/362481main_PainterPres_400.jpg
      and the accompanying Figure Legend:
      Dust-laden snow surface in the central Colorado Rockies in mid-April 2009 is compared with a near 100 percent reflectance panel as a reference for determining the decrease in snow reflectivity due to dust. The measure of visible solar reflectivity, or “albedo,” of the dusty snow is 0.61 relative to clean snow albedo of 0.98. That means that clean snow reflects nearly all of the incident sunlight in the visible wavelengths, while dusty snow absorbs a huge amount — about half — of that sunlight. Credit: Thomas H. Painter, Snow Optics Laboratory, NASA

      • So clean snow “reflects” 98% of all the visible “light” that strikes it. Incidentally, “light” by definition IS visible.
        Well a freshly evaporated silver front surface mirror, is the highest reflectance single layer specular surface reflector known, and the reflectance is 98% for that silver mirror.
        On the other hand the reflectance of a specular water / ice surface, is 2% at normal incidence, and about 3% total for a Lambertian diffuse illuminance.
        So that means that about 97-98% of the incident light on a water / ice surface, enters the material. If it rattles around inside by TIR, and then somehow finds its way back out the facet it came in on, well once again, only 97-98% will emerge, so in just this most degenerate of cases, the maximum reflectance or albedo that clean specular surface snow can have is 94-96 %, which is NOT 98%.
        Now in this ideal case, we assumed that TIR trapped the light, until it re-emerged form the entrance facet, so those TIR reflections are lossless.
        But what about a ray that enters the ice, and then escapes immediately at the first ice/air interface it encounters. Well that emerging ray back in air, is now only 94-96% of the original, and before it can get back out of the snow as part of that 98% reflectance, it must find another piece of ice to enter and TIR around, and then re-emerge, and that will cost it another 4-6% energy loss. Every single scattering encounter with a particle of ice, will cost the light about 5% on average of its incident value.
        I’d like to see some peer reviewed measurements of the full hemispherical back scattered (“reflected”) return from a sample of brand new just got here this minute snow.
        In the meantime, count me skeptical of ANY claim of 98% albedo from clean snow.
        And I’m not even at the NASA Snow Optics Laboratory. But right now, I am working at a NASA Ames address at Moffett Filed in Sunnyvale CA; but NO, I am NOT working for NASA Ames
        .

      • george e. smith –
        OK, got some theory. Is there any way to just go out and measure this in the field smaller than a tractor trailer and that the sled dogs could haul?
        Or must we invent the widget for the EPA?

      • George, I’d hazard a guess that clean, white small grained snow would probably have similar characteristics to a sintered PTFE or barium sulfate plate. (No snow here in Florida for me to check that… yet.) I think somebody assumed that 95% white (or whatever the target’s grey value) meant it was reflecting that much light and didn’t allow for its Lambertian qualities. You can make much scarier predictions that way.

  3. According to the linked description of their methods, all of their research was carried out within a mile (1.6 km) of a road … did these folks ever think of sampling a bit further from our diesel-and-gasoline-driven highway system?
    Sigh … another good idea fallen victim to selective sampling.
    w.

    • Yup, an interesting idea but the study was not deep, wide or thorough enough to provide much insight.
      Personally, I’m inclined to believe that particulate matter (produced by man or from natural sources) can measurably impact climate regionally if not globally. e.g. forest fires, volcano eruptions etc. And although there’s some controversy over the numbers, I am generally persuaded that particulate pollution does represent a health issue too. So I’m generally supportive of regulations and investment to reduce particulate pollution (and vehemently opposed to wasting money on CO2).

      • Just watch the green eruptions later this year when they don’t get the global CO2 regulations they want. The air will be thick with it.

      • I should point out that I am in no way, in disagreement with the notion that any sort of dirt on / in snow will hasten its melting, and it can happen a lot faster than one might think.
        The daytime surface melt / nighttime surface refreeze, quickly turns new snow with its fractal like micro surfaces, into significant sized optical windows, that transmit a lot of energy into the ice, wherein TIR trapping retains a lot of it. And as those now chunks of ice grow, they incorporate all kinds of absorptive pestilences into them, which ultimately absorb the solar radiant energy and convert it to heat (noun).
        My objection is to the mythology that snow is this magic ultra high reflectance goop that is supposed to be a significant contribution to earth albedo. It is chicken feed.
        Clouds are where the real earth albedo comes from. I’m talking total earth averaged solar spectrum reflectance. You know; the thing that goes along with Kevin Trenberth’s 342 W.m^-2 TSI.

    • Furthermore, wouldn’t the absorption depend on where the particulate matter was in the snow? A well mixed snow/particulates would certainly absorb less light then one where all of the particulate matter was on top, ergo the data they did collect is not that meaningful.

      • Snow melts or sublimates from the top down under solar heating. Once the darker layer containing particulate soot underneath is exposed in the Spring-Summer melt season, when sunlight is a a much greater factor, that particulate is now on the top all the way until the snow is melted to the dirt or rock layer. The dirty snow just keeps getting dirtier as the melt season progresses. Anyone who has watched the dirty snow piles accumulate in parking lots as the spring melt progresses sees that vividly.
        See here:
        http://www.nasa.gov/images/content/362480main_PainterPres2_400.jpg
        And then once any clean snow top layers are melted/sublimated down to the dirty layers, the dirt/soot stays on top, further accelerating solar absorption as the dirt piles up and decreases albedo.
        As here:
        http://www.nasa.gov/images/content/362479main_PainterPres1_400.jpg

      • joelobryan
        When dirty snow gets a new fresh snow cover, it may well continue melting under the bright white top. A flux of radiation inside the snowcover melts the snow around the dirt in there, sometimes it melts snow clearly from under (cool air + sunshine + thin cover on dark ground)
        Rain and dry air are as important factors in a melting / sublimation process. It depends on latitude and other local factors.
        Snow melting is a real science to study.

      • Hugh, not only is it a real science to study, just think of the number of different words the Inuit use to describe it.

    • If you’re going to go that far on the EPA and China’s dime, why not haul around some sleds and dogs and yurts and warm clothes. There must be something better or in addition to melting the samples in the motel, hauling water back to Seattle, and then shining a light through what has then been completely unmixed as Robert W Turner says.
      Selective sampling and maybe give some more thought to that methods section.

      • If you read the article carefully it said they filtered the water and then shined a light through the filter. and measured the amount of light transmitted through filter. No need to haul jugs of water back to Seattle. 0.25µ filters are readily available in usable sizes at any industrial chemical supply outlet.

    • But if they did that, they wouldn’t have been able to retreat to their motel rooms every few days. Oh, the humanity!

    • You want to see dark snow in North Dakota just go back twenty years to the time farmers in North Dakota engaged in (Summer) Fallowing 1/3 of their land every year. Fallowing means that by mechanically tilling fields for an entire year no ground cover to grow thereby “Resting” the soil.
      One result in the Winter whenever the winds blew were Ground Blizzards of snow and soil that blowing for miles before getting trapped in a Shelter Belt or Stubble field. We have photos from that era of our Shelter Belt filled literally to the top of the trees, surrounded by Fallow bare fields bare to the dirt starting within 20 ft of the trees.
      Traditional Following was displaced by Minimum or No Till farming about 20 years ago, with this practice no crop is grown during the “Rest” or Fallow years, the stubble isn’t tilled under and new growth is controlled with Herbicides. Two of the side effects of No/Min Till is that snow is trapped in the remaining stubble where it falls and doesn’t blow or drift NOR DOES THE SOIL. Now the tree claims rarely fill with dirty snow because there is now very little soil and snow moving with the wind and I would speculate the the ground is much more reflective than it was during the era when Summer Fallow was a common, almost universal, practice.

      • Folks can do a search – use Image Tab – and the word combination below
        eastern_washington dust devils
        While on Interstate 90 just west of the town of Ritzville I have seen a dozen dust devils at one time. During 20 minutes there were about 100. This was not snow season. Still, the soil goes up. Where and when it comes down . . .
        Can I get a grant?
        ~~~~~
        Snow that melts quickly will infiltrate and some unknown amount will be held as soil moisture. Much cleaner snow may sublimate. Near spring, some farmers plow the snow into rows leaving much of the soil uncovered. The local heating causes the row of snow to melt and go into the soil. Such will be a very tiny fraction of total land. It is interesting to see what people do.

    • Willis, In much of the plains area of the US and Canada, it is quite difficult to get more that 600m (0.5 mi) from a road. The area was surveyed into one square mile sections using the PLSS in the US and DLS in Canada then sold or given away to homesteaders largely in quarter section (160 acre) units. So farm roads — often unpaved — ended up laid out on a one mile grid.
      Try this. Go to Google maps and ask for Grand Forks, ND , back out to show about a hundred square miles — i.e. about 10 miles across horizontally. Then select Satellite view. This amazing 1 mile on a side grid (superimposed on a fainter half mile on a side quarter section grid) appears. and mostly there are roads between the sections although some segments are missing and one suspects many are very lightly used. The grid extends for hundreds of miles in all directions except where cities, rivers, or lakes interfere with it.

    • Good point about the selective sampling, but at least they got out on the road a bit. It beats creating a model indoors, and never double-checking to see what is going on outside.

    • Willis,
      Did it ever occur to you that this isn’t their first rodeo and that they probably know more about it than you do?
      Because I actually think before I run my trap, it occurs to me that heavy particulates might just have a limited travel distance which they’ve already reasonably characterized from prior work. Time and money being constraints, and Bell Jet Rangers costing megabux per hour to operate, I’m thinking they made some well-educated guesses about how best to spend their grant money to cover as much latitudinal distance at some meaningful resolution in the 67 sites they chose to survey. Also, because they’re interested in chemistry of the snow and not just what color it its, they may actually need samples from close to their sources to get concentrations good enough for their assays to work.
      But I don’t really know, because I don’t do their job for a living, and wouldn’t dream of presuming to think that I could offer them much good advice on it either.

      • Brandon Gates January 9, 2015 at 1:24 am

        Willis,
        Did it ever occur to you that this isn’t their first rodeo …

        Sure. But then I didn’t find any previous study of theirs doing the same thing, so I figured it might be their first rodeo of this particular kind. If you have evidence of them or anyone doing a similar study and restricting themselves to sample locations within a half mile of highways, I assume you’d have cited it … I found nothing similar.

        … and that they probably know more about it than you do?

        Sure, it’s quite possible that they know more about it than I do. However, my experience in climate science is that as Richard Feynmann observed, “Science is the belief in the ignorance of experts”. I fear I’ll take Feynmann’s word over yours. Me, I never assume that scientists or their studies are mistake-free, and I’m rarely disappointed in that assumption.

        Because I actually think before I run my trap, …

        Ummm … er … well … I fear we are woefully short on evidence for that claim.

        … it occurs to me that heavy particulates might just have a limited travel distance which they’ve already reasonably characterized from prior work. Time and money being constraints, and Bell Jet Rangers costing megabux per hour to operate, I’m thinking they made some well-educated guesses about how best to spend their grant money to cover as much latitudinal distance at some meaningful resolution in the 67 sites they chose to survey. Also, because they’re interested in chemistry of the snow and not just what color it its, they may actually need samples from close to their sources to get concentrations good enough for their assays to work.

        OF COURSE heavy particulates have a limited travel distance. If that’s the sum total of your insights at the end of your “actually thinking”, you’re in deep trouble. I started with that knowledge, and I thought
        “How would the fact that
        a) many of the particulates are generated on the highway, and
        b) they have a limited travel distance
        affect their results”

        Then I thought, “They’re making a claim that ‘North American snow away from cities is similar to Arctic snow in many places'”, but they haven’t looked at the snow away from highways.”
        So I pointed that out. And so far, you haven’t provided a scrap of evidence that this is not a legitimate objection to their survey methods, you’ve just provided handwaving and aggro accusations about my ignorance.
        Here’s my question, Brandon. If you were designing a snow survey of North American snow, would you restrict yourself to areas within a half-mile of a road? Please show your work …
        As to your observation about “Bell Jet Rangers costing megabux per hour to operate”, that’s dumber than a box of hammers. Get a damn snowmobile, put it on a trailer behind the pickup truck they used for the survey, and away you go. Helicopters??? This is a perfect example of why I believe in the ignorance of “experts”.

        But I don’t really know, because I don’t do their job for a living, and wouldn’t dream of presuming to think that I could offer them much good advice on it either.

        Well, at least that’s one thing we can agree on—I don’t think you could offer them much good advice either, so it appears you have an accurate view of your own abilities.
        w.

      • You don’t really know, but thanks for demonstrating, so we may know, that you will run your trap and presume to think you could offer Mr. Eschenbach advice before actually thinking. You demonstrate that you’ll jump to the defense of these folks without so much as checking the rodeo lineups. You don’t seem to realize that this post will be remembered when you run your trap in the future.

      • Willis,

        Sure. But then I didn’t find any previous study of theirs doing the same thing, so I figured it might be their first rodeo of this particular kind.

        Look harder next time. Here’s the study at hand: http://onlinelibrary.wiley.com/doi/10.1002/2014JD022350/abstract
        Searching for lead author Doherty brings up:
        http://onlinelibrary.wiley.com/doi/10.1002/jgrd.50235/abstract
        http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0889.2011.00577.x/abstract
        Even though he’s not lead author, Dean A. Hegg has 55 articles to his name going back to the 1980s. Not the doing the “same thing” but similar things.

        Sure, it’s quite possible that they know more about it than I do.

        Well that’s a start at least.

      • Paul Courtney,
        You don’t really know, but thanks for demonstrating, so we may know, that you will run your trap and presume to think you could offer Mr. Eschenbach advice before actually thinking.
        Honest people admit when they don’t know something for sure. That makes it clear that what they are saying is their own opinion, i.e., what they think or feel, about a particular concept. You are busting my hump for something I see as an obvious ethically correct form of communication. My advice to you is to think about that the next time you run your trap.

      • I’d said:

        But then I didn’t find any previous study of theirs doing the same thing, so I figured it might be their first rodeo of this particular kind.

        Brandon Gates January 9, 2015 at 7:44 pm replies

        Look harder next time. Here’s the study at hand: http://onlinelibrary.wiley.com/doi/10.1002/2014JD022350/abstract
        Searching for lead author Doherty brings up:
        http://onlinelibrary.wiley.com/doi/10.1002/jgrd.50235/abstract
        http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0889.2011.00577.x/abstract
        Even though he’s not lead author, Dean A. Hegg has 55 articles to his name going back to the 1980s. Not the doing the “same thing” but similar things.

        Thanks, Brandon. I didn’t say that they had not done studies of snow … and guess what. You found that they’d done studies of snow.
        What I said was, I didn’t find any previous study of theirs doing the same thing, a study which claims to cover a wide area but only sampled next to the roads … and as you agree, neither did you. I guess you’ll have to look harder next time.
        So I’d say that the evidence so far is that this is their first rodeo of this particular kind.
        But this is all just a red herring. Whether it’s their first or fiftieth rodeo is immaterial. What I said was that if you want to find out what the snow conditions are across a large area, the idea of only sampling within a half-mile of a road seems like a very curious method in any rodeo. And you haven’t brought up anything to challenge that, except for a hilarious claim that getting off the road would require a Bell Jet Ranger helicopter.
        w.

      • Deflecting as usual, socks. This isn’t about fishing. It isn’t even about carp. This is about one more alarmist climate myth being busted. No wonder the interest in changing the subject.

      • Seriously Mr Dbstealey…..when you tell someone they are full of “carp” in a public forum, don’t you think that we should ask a fisherman such as Willis what his opinion is of carp?

      • socks,
        Are you really that thin-skinned? And can you not recognize irony as humor?
        As for a ‘public forum’, no one is forcing you. Are they? Personally, I would rather not see your misinformation posted. Then I wouldn’t feel the need to correct it.

      • Mr Dbstealey…

        Let’s wait until Willis provides us with his opinion of a person that is “full of carp.”
        While you are on the subject of misinformation, can you please inform us of how global temperature (T) rises or falls the most at night ?

      • Willis,
        What I said was, I didn’t find any previous study of theirs doing the same thing, a study which claims to cover a wide area but only sampled next to the roads …
        Equivocation games, really? Up your game.

      • Socrates,

        Do you think Willis the fisherman would be interested in someone that is full of “carp?”

        lol. Maybe, if only for bait. What kills me about that post is the parting shot:
        Finally, anyone can play with the WoodForTrees site and create millions of charts, but most of them are worthless …
        Edited for accuracy.

      • Socrates,

        [responding to dbstealey] While you are on the subject of misinformation, can you please inform us of how global temperature (T) rises or falls the most at night ?

        Is he on record saying that?

    • Willis: Have you ever been in ND or the Canadian provinces adjacent to ND in the winter? The area is very sparsely populated and most of the roads are county or township roads many of which are not paved. In the winter these roads are usually covered with compacted snow and ice. If the temperature is cold enough (near -17°C) driving on these roads is like driving on concrete. Furthermore there is not a great deal of traffic on these roads. Usually the local school bus or a family going to town once a week is about the most you will see for vehicular traffic. Families in this region have multiple snowmobiles for their everyday chores or recreation. IMO your snipe about sampling less than about 1 mile from a road is just that “snipe”.

      • greymouser, first off, yes, I’ve been in both North Dakota and the Canadian provinces in the winter. And?
        Next, I’m not sure what your point is. My point was this: in areas such as you describe, the main source of human-made snow pollution is black carbon from diesel and gasoline engines on the roads. As a result, sampling near the roads will tend to overestimate the human impact on the snow. Far from being “snipe”, this seems to me to be a serious objection to any generalization of their results. And while you may disagree, your calling my objection “snipe” is just … well … sniping …
        As to the idea that “a school bus or a family going to town once a week is about the most you will see for vehicular traffic”, that’s not my experience at all. People drive to work, both in ND and Canada, and they visit families, friends, and lovers, and they go out for a drink, and they go shopping and to the movies … and they use the roads to do so.
        And being someone who prefers facts to anecdotes, here’s the number of miles driven on rural roads in North Dakota by month in 2010, from here et seq.

        Around 350 million miles driven on rural arterial roads in North Dakota in summer, and 250 million miles driven in winter … sorry, greymouser, but 250 million miles driven per month in the depth of winter, that’s a whole lot more than “a school bus or a family going to town once a week” …
        I also don’t understand your comment about how in the winter “driving on these roads is like driving on concrete”. Driving on roads is always like driving on concrete, or driving on asphalt, which is little different. What does that have to do with black carbon on the snow?
        Anyhow, I truly don’t understand what your point is. Some clarification would helpful.
        w.

      • Willis: re: the 250 million miles per month driven in ND as you cite below, Nowhere in that table of data is a breakdown of where in the state that mileage occurred. My guess is since that data was from 2010, it is likely to be heaviest west of the Missouri R. (the area known as the Williston Basin). But without a regional breakdown of travel patterns, that 250 million miles is just a figure. in most parts of the state you will find a N-S/E-W road every mile. So define for me what you consider “near” the roads.

      • Perhaps it would have been been better if we had the GPS coordinates for the sample sites. I noticed in the press statement that they sampled areas away from cities and major roads.

      • Willis,

        Next, I’m not sure what your point is. My point was this: in areas such as you describe, the main source of human-made snow pollution is black carbon from diesel and gasoline engines on the roads.

        We’re getting somewhere. Maybe the folks who did the actual field work weren’t so entirely clueless after all. Emphasis on field work. As in, their eyeballs registered the conditions of the surroundings in which they deliberately found themselves.

        As a result, sampling near the roads will tend to overestimate the human impact on the snow.

        It’s even worse than that. Their selective sampling in N. America will tend to bias their findings on human impact on snow in S. America. Asia. Europe. Antarctica. Greenland. These guys need to be tossed into the brig for doing such schlocky work.
        It goes without saying that the first idiot who loads these “data” into a model and assumes that road and traffic density are homogenous everywhere it snows should be summarily executed.
        While I’m at it, someone really ought to tell these nitwits that driving vehicles isn’t the only human activity which might have some impact on snow and ice.

  4. “Whether the pollution the researchers found in North Dakota is enough to change snow melt timing will have to be answered by region-specific climate models, Doherty said.
    “But first the models have to do a more accurate job of representing the amount of dirt that’s in the snowpack,” she added.”

    Good luck that!!!!! One of the many reasons the climate models fail, and will continue to do so. But that won’t stop the modelers from running them and then publishing their garbage output. As long as there is grant and funding money to be had for grantees, they will continue to put out what the grantors want to see.

  5. Well does this mean the snow melts hours sooner, days sooner or weeks sooner? Here in NC the snow is rarely on the ground more than a couple of days, especially from mid-Feb on. Even if the snow is around long enough to interact with atmospheric particulates, does it really matter?
    As you go north, obviously the snow will stay longer, but again when a warming event occurs the snow can go fairly quickly. And most of the time, sunny days are associated with cold temps, so we get some additional topical melting that refreezes at 4pm? Generally it takes a low pressure system pushing air up from the south or rain to melt the snow.
    The only place where I could see this as a possible issue is with semi-permanent snow fields way up there, and according to the article, these are the “cleanest” areas anyway.

  6. I first noticed this as a boy in northern Alberta in the thirties lots coal used then. I wondred if the airplane traffic increase in the artic in the 1960s onward burning JP4 made a difference. I was there from 1955 to 1978 and could really see any.

    • Burned a lot of Lignite in the Dakotas at that time too, I used to retube those Coal fired boilers and you could smell them 5 miles down wind. Old timers used to tell me about the inversion layer that trapped Minot in smog whenever the wind blew over the Souris River valley rather than down it.

  7. A little OT: thanks to AW for removing the “Solar activity at birth – Life expectancy” post. That was borderline astrology-esque junk science, IMO.
    J.

  8. I thought that every rain drop/snow flake was formed with a speck of dirt at the centre.
    How have they differentiated between those and specks of dirt from other sources, for example wind-blown or vehicle exhaust subsequently deposited on the snow surface?

  9. Back in the late 60s during the Global Cooling scare, it was proposed to sprinkle soot on the Arctic snow fields to prevent the imminent ice-age. Seems like Chinese industry is doing just that 🙂

  10. This is how we save ourselves when the planet starts to cool. Dot the great white north with little coal-electric plants designed to maximize soot production and just produce enough electricity to run the operation (unless there are nearby towns that could use more juice). Just run them in the winter (or switch to soot-free burning the rest of the year if they are being used for electricity supply).
    Should be able to easily reduce albedo enough to offset significant cooling IF we have enough infrastructure up and running in time and use it in time. We need to be building this NOW.

  11. At least they got out from behind the computer screen and did some leg work for a change. Kudos for that. They could have sat there and done the famed “reanalysis” of data using a sophisticated climate model which seems to be the standard these days.

  12. Most of the rural areas that I’ve lived in prefer to dust the roads with grit and ash and often locally common dirt.
    Ash is a discard and less expensive than salt.
    When the weather is cold, the grit makes for better traction up hills. Not a lot of help descending hills though, downshift and go slow.
    Which leaves me wondering if road snow control practices were taken into account. Or even if the snow collected was far from local contamination sources. I’d expect easy walking points near the roads would be heavily road contaminated and biased.
    How long and how often do these folks ‘collect yellow or dark snow’ after snowfalls?
    Not forgetting that ‘paved roads’ in much of rural America are just graded soil/earth and tar oil sprayed to minimize rain washout and hopefully prevent ruts or washboard surfaces.
    What is needed are definitive ‘control’ samples; ideally collected since the 1930s.

  13. Where I live, people don’t think snow is naturally dirty enough so add things like salt hoping to make it go away faster. Where I grew up, people would add coal ash too. Finding that nature is catching on might be a good thing.

  14. Anthony, if you put a disaclaimer, such as “Funded by the EPA” ahead of the article, we could have skipped to the pre-determined conclusion. 8D
    Seriously though, it seems that the entire purpose of the “research” is to shut down US energy production. Isn’t it interesting that the “researchers were particularly interested in the Bakken oil fields of northwest North Dakota.” and “With all this oil exploration, diesel trucks and new oil wells, people wondered: Is there a huge amount of air pollution making the snowpack darker?” said lead author Sarah Doherty, a research scientist…”, er, paid government shill. People wondered? I think we know which people…
    The comment from Willis sums it up. All their “research” is done near roads. What would be interesting is if they did this “study” at presetermined, published sites, for 30-50 years and present the data and any observable trend. That would be science. This one time sample demonstrates and proves nothing. Kinda like the ozone hole, from “look, there’s a hole”, to “we caused it.”
    Eric

  15. o/t but brrr.
    20 below 0 (F) last night with wind chill of approx -30 to -35.
    high temp today was bouncing between 0 and 1.
    my snow is usually pure white here, seldom see anything in it.
    sometimes during the first storm of year, before ground fully frozen, if its windy during storm will see some dust mixed in.

      • Don’t know for dmacleo, but here in Northeast Kingdom of Vermont it got down to -22F – no wind thankfully because then we usually lose power.
        That’s a pretty good temp – outside sensor, mercury register so not clearly the best (been thinking of upgrading but slight disposable income issue especially with electric costs = damned wind turbines weren’t whopping last night but still paying for them), and we can’t see another house from ours so no local (urban) heat sources. Plus I was up feeding the carbon burning wood stove – went with ash for last night – every couple of hours and would go look.

  16. I think that the increase in human and warm-blooded animal populations has a far greater effect on “global warming” than the carbon in snow does. In 1850 there were about 1.2B humans on earth and now there are 6.7B. The difference (5.5B) accounts for an additional 550 GWatts of radiated heat (100W/human) that must be managed by the Earth’s atmospheric thermoregulation scheme. Throw in the larger animal population and there may be as much as a TeraWatt of extra energy to be dealt with.

    • “…additional 550 GWatts of radiated heat (100W/human)
      Yikes, 550 GW/hrs!
      If I did the math right, that’s over 31 Hiroshima bombs per hour.

    • What we eat and metabolize would have been metabolized by some other creature. Besides, your additional 5.5E11 Watts is miniscule compared to the background energy flows. Bio-productivity on Earth though has indeed cycled wildly up and down through geologic time. The Glacial periods are one of decreased biological activity to be sure, and then global average temperatures were only 8-10 K lower than today.
      But be very careful of which way you point that arrow of causality.

  17. If American snow is getting dustier and dirtier, surely you need to look east for the source – to China.
    Here in the UK, we regularly get dust from the Sahara, so these airborne particulates can and do travel a very long way.
    Ralph

  18. Sal, what an incredibly human-centric attitude. That’s as bad as any warmist!
    There used to be herds of plains Bison that took days to thunder past. The sheer mass of wild animals on this planet exceeds humanity. There is probably more insect life than animal, again just by mass. Imagining that human population increase changes the animal balance indicates a lack of imagination.

    • CodeTech, what an incredibly mammalian-centric attitude 😉
      We live on a planet overwhelmingly dominated by bacteria.
      http://phys.org/news/2013-02-bacterial-world-impacting-previously-thought.html
      Silliest statement of the millennium:

      “Only within the moment of time represented by the present century has one species — man — acquired significant power to alter the nature of the world. ”
      ― Rachel Carson, Silent Spring

      Obviously she never heard of The Great Oxygenation Event
      http://en.wikipedia.org/wiki/Great_Oxygenation_Event

    • The point being made is the delta in human generated heat since 1850 not the absolute value. Aside from that, the point was being made, somewhat tongue-in-cheek, that there are all manner of things that might affect climate and, that being said, there is only a very small difference in global temperature. I’m not sure whether the difference in temp is even really discernible due to varying accuracy in recording the data over time.

      • Now that’s a point I can agree with.
        If hypothetical space aliens were to examine Earth (being highly advanced in all sorts of science, unlike our NASA-GISS boys), my guess is they would be gobsmacked at how temperature stable Earth’s climate is and has been over hundreds of millions of years.

    • Actually it is a reasonably well known fact (and echoed in most entomology textbooks) that simple ants outweigh humans on this blue orb.

  19. I’m not really sure how much of a problem this is. For example, imagine the last glacial period. We saw ice that hung around for 100,000 years. All during that time the ice was collecting dirt from the wind, stuff that drifts down from meteor dust, and soot from natural fires, some of which were likely even coal fires started by lightning strikes. As these glaciers began to melt, the ice would melt leaving the dirt and soot behind. As these glaciers were melting in the summer they must have looked more like dirt than snow as the accumulation of 100,000 years of junk deposited by the atmosphere accumulated on the surface.
    Is the modern load of junk any worse than what we might have seen during the last glaciation where there were huge areas that are now prairie which were desert at that time?

  20. They are obsessed with anything man does that “might” have an effect on climate. It’s insane. Air quality is what matters, since cleaner is healthier to breathe. But that is strictly a regional issue.

    • More correctly, they are obsessed with anything that might lend support to their agenda. As Bjørn Lomborg pointed out in The Skeptical Environmentalist by any sane measure, we have cleaned up our act immensely during The Git’s lifetime. And his reward for that endeavour was to be roundly criticised.

  21. Soot is not about climate change but it is very bad for our respiratory systems, and circulation. These particle get stuck in our lung and in aveloli of the arteries.

  22. “Their main focus was black carbon, a very light-absorbing particle emitted by burning diesel, coal or wood”
    Read this blog very carefully, this is not CO2 “pollution”, this is the real thing such as soot and other particulates.
    This constitutes in my mind that “scientists” are looking for another excuse to ban the use of energy.
    Soot while a problem in itself, is not CO2 and is not a greenhouse gas and cannot have a “positive feed back ” on heat in the atmosphere.
    Seeing as CO2 is getting increasing bad press as doubt about its unproven role in “Global Warming” increases – maybe attacking with actual pollutants may appear to be a good way out.
    Especially as the only way to restore untouched pristine snow is to devoid the world of 1. People, 2. volcanos, 3. Forest Fires, 4. Desert Dust, 5. Farming, 6 Mining and 7. wind
    What ever happened with Acid Rain?
    Cheers
    Roger
    http://www.rogerfromnewzealand.wordpress.com

  23. “In fact, they found that in the Great Plains states up to half of light absorption is due to organic matter, or “brown carbon” from burning fossil fuels and from soil that mixes in with falling snow.”
    It’s call dust…and most of it is dust

  24. Well no problem, we’ll just create a tax to fund research into turning dirt, soot, blacktop, trees, just about anything on the planet into lighter colors. This has the side effect of creating permanent employment for many scientists and a pastel colored earth which after all could be very attractive.
    A backup plan would put blinds similar to what you have on your home windows that orbits around the planet keeping it on the sun side. Then when you need the heat you open the blinds; too hot and you close the blinds. A very practical solution with some serious bang for your tax dollar. Not to mention NASA really does need a decent project with some impact to work on.

    • Alx: Your backup plan is plainly absurd. Those strings would get all tangled, and would need to have giant warning tags re: choking hazard permanently affixed. In space. Sorry, must I really /s?

  25. So they have done exactly one incomplete survey and draw conclusions that it is worse than we thought.
    A couple of questions:
    Worse compared to what – what is the baseline survey when you only collect ONE point in time with incomplete geographic sampling?
    How will this help to improve the almighty models when I see no quantification of sources – just assertions that it is “Man-Made”?

  26. Hmmm… I thought about a title of Simplicity and Simpletons….
    these people obviously have not spent much time winter camping or hiking the snow-line woods in the early or late spring. Or if they did they were remarkably un-observant. Now if you are a thirsty hiker and you clear off that accumulated soot/dirt they talk about to scoop out some refreshing coolness – then go your way and comb back a day or two later – you will find your scooped out portion a big hollow hole while the high-albedo soot/dirt covered stuff is still pretty much how you left it. Strange – No?? While a marginally thin layer of soot/dirt/dust does without doubt speed the melt process, once it is thick enough other factors kick into gear which reverse the process… This is why in late spring the longest lasting sections of snow still lying around in the alpine are not the pure white ones, it is those covered with a layer of dust/dirt that all but hides the few bits of icy whiteness.
    so how to explain the hiker’s mystery… It is my observation that pure white snow, when melting first crystalizes into ice crystals. The albedo of those crystals – whose surface layer demonstrates an orientaton that is anything but round or random – is different from snow. That surface is anything but flat. The more the crystalization the more profound the increase of surface area – my off-hand observation is anywhere from 5 to 50 times. The interior reflectance mentioned by george e smith above sky-rockets in such an environment. But all this is not true of soot/dirt covered snow. Why? When the snow-ice crystal pack melts, the melt water seeps downward, all the more quickly as the freeze thaw cycle crystalizes the snow layer. However, a thin but even layer of soot/dirt actually holds the moisture at the surface and at night re-freezes into a solid (relatively think) and rather smooth layer. As the hiker will tell you it is rather hard on the hands to break through this layer to find the white stuff underneath. This smooth and relatively thick layer reduces air-flow, dramatically reduces surface area, and when the soot/dust layer is thick enough actually forms a kind of radiative insulation layer. What thickness? I will leave that for someone with funding to find out…

      • Lakota and likely the other plains Indians used to call the period we call February the moon of the snowblind.
        Grease and soot smeared under the eyes helped minimize the reflection off of the cheeks and nose.

    • Good practical observation and statement Les.
      Even after topping off the crusty ice stuff, when melting the creamy white inside snow, there is still an amazing amount of particles and other stuff in one’s cup of water. Good for you, builds immune functions and adds texture to tea.
      (Personally, I kick off the crust and then scrape to reach the clean snow. You are right, it hurts the hands which are darn cold already and can cut them.)

  27. It would not be easy to model this accurately and determine an overall effect on albedo from soot. The soot and other material which darkens snow is not evenly distributed through the snow pack but accumulates in layers. The layering stucture changes as new snow puts down a fresh layer on top; as grime slowly accumulates on the surface on days when it does not snow; and as melting from both bottom and top accumulates the soot into darker bands. The darkness of a band is not going to be a linear function of how much soot there is in it – a law of diminishing returns sets in as the dark crust thickens. And the albedo is determined by the top few inches only so fresh snow can completely negate the effect of buried soot.
    To get some kind of ‘forcing’ out of this, which is what climate scientists would seek to do, you would need to determine the effect on average albedo, which is a function of melt frequency and depth; snow frequency and depth; and the average rate of deposition of soot. All three will vary through the season and will be strongly influenced by location. Furthermore the pattern of snow deposition varies greatly from season to season as anyone who lives in snow country knows. No two seasons are alike. At best a model can give you an average of what migfht happen over a couple of decades of winters.
    There are also some nasty feedbacks here. Local albedo and snow coverage changes the local weather. For example if nearby lakes are frozen over the lake effect will be diminished. Snow coverage will also change the rate of deposition of dust. Agricultural dust in particular is going to be an obvious function of snow coverage as dirt that is safely buried under a protective layer of snow will not be putting dust into the air. Some of that dust will be “regifted” from melting snow pack. And the amount of dust will depend also on the strength and direction of winds.
    Finally, much of that dust has travelled a very long way. Some of it is no doubt volcanic dust or dust from big forest fires on another continent. So you have to consider a whole continent’s worth of weather between where it was emitted and the snow you are trying to study. And any assumptions you make about such sporadic events are likely to be at best a poor approximation of reality in any given season.
    Not an easy problem to model at all. Lots of parameters to tweak to fit any elephant. Many ways to get the answer to ‘come out right’ and any model would be virtually impossible to falsify. These factors would cause most scientists to proceed only with a great degree of scientific caution. I don’t expect climate scientists to behave that way though. Scientific caution seems to have evaporated from this branch of science. I expect very soon we will be hearing that it is worse than we thought based on some simplistic and totally inadequate model of snow darkening, and some climate activist will be in the newspapers calling for massively expensive changes to agricultural practice as a result.

    • …some climate activist will be in the newspapers calling for massively expensive changes to agricultural practice as a result.

      That’s so much easier than observing modern farmers’ implementation of soil conservation practises.

  28. I often find myself wondering if these scientists even bother to learn the history of the areas they make their studies on. Or their climate for that matter. Now forgive me if I am wrong but that entire area is part of the Great Plains, famous for Tornado, and howling winter storms and possibly being part of the great dust bowl…. soooo yah I bet their snow does have a lot of crap in it. SO WHAT!

  29. “The work was funded by the Environmental Protection Agency and the China Scholarship Fund.” I seriously don’t trust statistics from either one of those organizations.” Even better, they want MODELS also. You just can’t make this stuff up. Oh wait

  30. What I have noticed is that the LAST ice or snow to melt in the spring is the ice or snow covered by a layer of soot or dirt.
    There is a point where the dark layer of material turns into an insulator and prevents the melting of the snow or ice rather than enhances it.
    There is always a point where new snow falls on top and the Albedo goes back up to the 85% of fresh snow. Eventually, the front melting edge of many glaciers turns black. When the large ice age glaciers were retreating at the end of the ice age, they might have all been dark-colored with a layer of dust migrating to the top.
    Obviously, this is a complex process. Our intuition is that will always make the front edge melt faster. But what if it is actually the opposite.

    • That’s where of course careful real world observations, converted in raw data, converted in information aids the conceptualization of what really happens. Sort of like NASA’s fanciful CO2 simulations pre-OCO-2. Not even close.
      But that’s okay. Now they have data to inform them of what really happens, and probably sadly for the modelers, it’s very non-linear and non-uniform unlike their modeled assumptions.
      I would imagine snow albedo changes over the Spring melt season is similar. Very chaotic, non-linear and widely varying from year to year.
      I disagree with your dark layer-insulator conjecture. That dirt or soot layer heats up under the vis-UV solar heating. During the spring, that heat flow will be to the colder snow-ice. At night it will act as a continued source of heat to the underlying snow layer.

    • Bill Illis
      That is exactly my experience, too.
      As a young man in the BC woods, I strewed ash from the stove on garden patches and trails, thinking it would accelerate spring melting. It did the first day of sun, then, as the individual clumps sank into the snow, they were lost until all the surrounding snow had melted and there were lines of wood ash lying atop a layer of ice.
      It took me two or three years to figure it didn’t work and I was pretty indignant that it didn’t.

    • Also note that snow dumps can last into August because there soot/dirt/sand layer migrates to the top and then provides an insulating layer.

    • Well, that was a total waste of ten minutes. Not only do you make the claim that it’s all related to the angular momentum of the planets, you then only mention angular momentum twice, with no explanation at all of the graph in the post.
      To top it off, there are no comments … don’t waste your time, folks. I did and I regret it. “Comprehensive evidence”? Don’t make me laugh …
      w.

  31. If the only problem with climate on Earth were caused by soot and othe particulates changing the albedo of snow cover on the poles, exactly how would a”carbon tax” help remediate this problem ?

  32. It will be interesting when they go back to the same sites in later years to take the same measurements to examine the reproducibility/variance of the results.
    lol
    As if.

  33. I haven’t seen snow but if I kicked dirt on some should I reel back in guilty horror and tell my little granddaughter
    her dream of a long and happy life is now impossible.

    • Ash layers do have rather low albedos. But usually they are limited in geographic extent and in time.

  34. 1. Since they only sampled up to 1/2 mile from the road, we don’t know how far the soot extends.
    2. What we do know is that the road itself is a major contributor to early springtime melting. Anyone who grew up on the frigid prairies knows that springtime melting shows up earliest alongside exposed surfaces such as roads, buildings, even fence posts. This early melting exposes the earth which then promotes more melting in an ever widening positive feedback effect until the snow is gone. So, unless the soot extends WELL beyond the boundaries of human activity, I suspect that the roads and houses have a larger effect in the immediate area than does the soot itself.
    3. I didn’t notice any measurements of snow brightness or albedo to go along with quantifying the levels of soot in the snow. So, without that data, what exactly are they going to put into the climate models? Without knowing what the difference between pristine snow and their samples was, they would first have to model the snow and the soot, with no data to start from. That would be one h*ll of a job, modelling snow like that. Yes, it would be a snow job….
    4. The above having been said, I do have anecdotal evidence, compelling anecdotal evidence, that snow has in fact changed substantially over the past few decades. About 25 years ago, I threw a snow ball at one of my boys who was then about 5. Knocked him flat on his keester, and earned myself a scolding from the boy’s mother. 20 years later I repeated the experiment. I used the exact same boy, was careful to form a snowball of approximate same size, and hurled it from the same distance. It had nearly no effect on the boy. I had planned to cut the snow ball open in order to count its rings, but the boy considered it of more value in washing my face, eliciting howls of laughter from the aforementioned mother. This is proof positive that global warming is negatively affecting snowball efficacy.

    • Car tires are continually making large volumes of black carbon dust, and the road way itself is continually deflating through microscopic wear.
      Exercise:
      Get a white car, wash it carefully, drive it literally all day through city streets, then wash it again at the end of the day and note the copious dark black fine dust coming off in the rivulets. That’s mat-black tire rubber dust and bitumen detritus that comes up of the road surface and sticks readily to any surface.
      So yeah, if your samples are all 1/2 a mile from a road you’re going to get a whole lot of black carbon-rich sooty looking dust in the samples.
      Clever.

  35. What a joke. U of W folks are clowns in gowns saving the planet from people dust. Maybe they should clean their own campus before striking out to rid the planet of evil humanity.

  36. Which country has warmed the least in the last 50 years? Bolivia, home of what’s left of the Chacaltaya glacier, which boasted an ice cave 20m deep 50 years ago. I’ve long contended that the road built in the 30’s to turn it into a ski resort hastened its decline. –AGF

  37. Back in the day, when most everyone in the cities burned soft coal to warm their abodes, London and others were giant smudge-pots in winter where I imagine snow turned black before it even hit the ground. I do not believe history records any great climate calamity resulted. Lots of “lungers” hacking and coughing, though.

  38. This is another transparent alternate attack on petroleum, and coal from the same people who have told us that CO2 is a pollutant… It is almost laughable, especially considering that rural weather recording stations in North America nearest the areas where the snow was sampled have been showing declining temperatures in winter and spring for over the last two decades.
    Earlier snow melt could have a small effect on atmospheric temperatures in these regions, but the data that supports this theory is currently non-existent. Apparently the people conducting the study never bothered to check the historical records in the regions they were studying. It seems like a more rational approach would be to check the data from nearby recording stations FIRST to see if there has been earlier warming before going to the trouble of collecting snow samples. What are they trying to prove??? …that winter and spring temperatures in rural areas would be declining even faster without particulate??? I am sorry… I don’t get it.

  39. Noting the discoloration of the snow in Greenland in the picture at the beginning of the article, was that caused by the Diesel trucks from the fracking, etc.? I suspect that might be due in part to volcanic eruptions which spew lots of solids high into the atmosphere.
    I view that this article has the agenda to stop energy production on private lands via some edict from the EPA which has not been slow to kill fossil fuels while taking credit for the oil and gas production and all the associated jobs.
    After the coal mines are closed the next target will be oil and gas which the administration will be replace by imaginary energy sources such as biofuels, solar and wind.

  40. Just one last thought. Wouldn’t dust and soot help replenish the top soil after the snow melts?

      • John,think it through. First of I said “help”. Some of that “dust” maybe organic and “soot” contains carbon. Down in Yuma, AZ the farmers burn the what is left of the crop after harvest to incorporate carbon back in the soil.

  41. They asked me how I knew
    It wasn’t CO2
    I of course replied
    Without being snide
    It cannot be denied
    They said some day you’ll know
    When there’s no more snow
    You had to pay the price
    For loading Hansen’s dice
    Smoke gets in your ice
    Someone showed that, by a farmer’s road
    Snow’s not white, but dirty brown
    So, in May, or sooner now they say
    The sun will warm the ground
    Post-modernists will state
    That we shouldn’t wait
    CO2 or not
    Pollution isn’t nice
    Smoke gets in your ice.
    We’ve heard it more than twice.

  42. This study is wrong in so many way, first and foremost running around and take snow samples randomly throughout a state for one winter, will tell you nothing. I have lived most of my adult live in North Dakota, I have driven and walked throughout North Dakota. It is a diverse prairie state going from tall grass prairie to short grass prairie. It has a diverse climate moist on the east, dry in the west. It is not hard to get a half mile off the roads, if you would only look at a map first and are willing to walk! Yes a good part of it is privately owned yet the are Nation Grasslands on both sides of the state, throw in a large number of Waterfowl Reproduction areas and several Nation Refuges and a Nation Park you have plenty of diverse areas to study with some of those areas you could be assure they will remain relatively undisturbed.
    A study like this would be of value if you were to do it over the period of at least 30 years or longer, at that point you might have data of some value, not only would you have to collect that data over a long period of time you would have to pick you test spots carefully trying to cover the state well and having some very remote sites, and others right in the middle of farmer fields. Some close to roads other far away some starting at the road, running all the way across several sections at a set intervals. Some should run the same way in the absolute middle of nowhere, there are site where you could do both throughout North Dakota. You would also have to document land, agricultural and industrial changes. It would not hurt to have a test site one or more active strip mines that are in North Dakota. If you did that it might be revealing what you find.
    Instead from what I read a so called study where a bunch of people running around taking samples for a single winter, looking to me as a rather random affair. Then to top it off they were thinking that they might learn something about dust in snow. If that not the height of stupidity they top it off by create a computer model based a what I would guess is a huge WAG and are astounded that the model does not tell them much. I would like to think science today has not devolved to such a moronic level, but with this study and many others it looks like it has. Keystone cops all over again, only this time they were not trying to be funny. On the surface this seem to like to waste money, if there plan is like what I have outlined above it may not be but if the are doing willy-nilly measurements and only for a short time it will be a waste of money I can only hope it was not tax payer money.

  43. “On the surface this seem to like to waste money.”
    On the surface, yes but if you wanted to have control you got to start somewhere.
    OKLAHOMA CITY — The U.S. Environmental Protection Agency is considering a crackdown on farm dust, so senators have signed a letter addressing their concerns on the possible regulations.
    http://www.news9.com/Global/story.asp?S=12899662
    U.S. farmers oppose EPA’s proposed dust regulation
    http://www.reuters.com/article/2010/08/19/us-epa-dust-regulation-idUSTRE67I5T120100819
    Do you think the EPA has an agenda?

    • The EPA’s proposal could result in drastic reductions in productivity of any crop which is sensitive to planting/harvest time, as soil prep/planting/harvest dates could be missed if conditions are too dry and/or windy to work the soil under EPA guidelines. This would seem to fit with the overarching Green agenda of reducing human populations.

  44. How come it is black in greenland , when it snows my way it is pristine white to the eye. Has that Greenland photo been photoshopped like the usual steam towers at power stations on every Guardian article about pollution.

  45. ‘During their almost 10,000-mile trek across North American snowfields, the researchers were particularly interested in the Bakken oil fields of northwest North Dakota.
    ‘“With all this oil exploration, diesel trucks and new oil wells, people wondered: Is there a huge amount of air pollution…”
    ‘What they found was that these activities do appear to be adding extra soot to the snow, but perhaps just as important is the dirt. …and all the extra truck traffic on unpaved roads means dirtier snow.’
    My, my, my, me thinks the bias is showing. If one wants to consider the dirt all the extra truck traffic kicks up why stop with the Bakken oil fields? Certainly all the newly bulldozed dirt roads to accommodate the massive increase in truck traffic to construct the vast wind farms throughout the Great Plains should merit at least a wee mention? Shouldn’t it? Certainly the areas scraped, bulldozed, shoveled, leveled, and dug out from Indiana, Illinois, Iowa, and western Minnesota (to name just a few) for these windmills would have to exceed, by Godzilla sized bucketfulls, the land area kicked up by the Bakken oil fields. Why the omission? Does the EPA want its money back – or, did they get their money’s worth? Unfortunately the answer is yes.

  46. How dirty was the snow back in the 1800’s? 1700’s? You know, has the amount of dirt really changed much? If so, how much? Just finding some soot and dirt is no great shakes without context.

  47. For U.S. farmers, changes in the snow’s reflectivity could affect when the spring melt will occur and when meltwater will drain out.”

    The sooner the snow is gone and the soil is firm, the better is goes for this plowboy.

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