Got this in the mail just as I posted my open thread announcemnt. I’m too busy this weekend to say much else except to post this tweet from Bill McKibben and some past blog excerpts and invite discussion.
The reflectivity of the Greenland ice sheet has…literally dropped off the bottom of the chart. This means MELT. http://www.meltfactor.org/blog/?p=514
That graph says one thing to me – black carbon soot, especially since lower levels of Greenland, near the oceans and glacial terminae don’t exhibit the same effect:
CO2 doesn’t change ice albedo, but smoke from the industrialization of Asia does, and I think it is a factor. See why below.
It is possibly the same reason for the sea ice decline and the melt pools we’ve been seeing on the surface. Note that this year the melt accelerated quickly once the sun was regularly over the horizon in May…so that an energy dissipation in the ice when soot absorbs solar radiation.
Recall this experiment with soot on snow done by meteorologist Michael Smith of WeatherData where soot made a huge difference.
I also covered the issue in:
Greenland Ground Zero for Global Soot Warming
They say a picture is worth a thousand words, this moulin in Greenland a real eye opener:
He writes:
In the winter a huge among of snow are accumulated on the Ice (2-3 meters, sometimes more) and we are not talking about 1 or 2 square-miles, it’s about 100.000′s of square miles (up to 1 million) on the Westside of the Ice cap and a similar picture on the Eastside… when the melting season starts in april-sep… the meltwater has to go somewhere, and for sure it goes downhill in huge meltwater rivers.
The black stuff on the bottom of the lakes is carbon dust and pollution in general… but not from one year, but several decades (the topographical conditions don’t change from year to year). On a flight over the Ice Cap a sky clear day, you can see hundreds of huge lakes with the black spot on the bottom.
– Anthony
The website of Jason E. Box, Ph.D. meltfactor.org has more graphs and says:
Latest Greenland ice sheet reflectivity
These albedo visualizations are discussed here and here.
About the Data
Surface albedo retrievals from the NASA Terra platform MODIS sensor MOD10A1 product beginning 5 March 2000 are available from the National Snow and Ice Data Center (NSIDC) (Hall et al., 2011). The daily MOD10A1 product is chosen instead of the MODIS MOD43 or MCD43 8-day products to increase temporal resolution. Release version 005 data are compiled over Greenland spanning March 2000 to October 2011. Surface albedo is calculated using the first seven visible and near-infrared MODIS bands (Klein and Stroeve, 2002; Klein and Barnett, 2003). The MOD10A1 product contains snow extent, snow albedo, fractional snow cover, and quality assessment data at 500m resolution, gridded in a sinusoidal map projection. The data are interpolated to a 5 km Equal Area Scalable Earth (EASE) grid using the NSIDC regrid utility April and after September, there are few valid data, especially in Northern Greenland because of the extremely low solar incidence angles. The accuracy of retrieving albedo from satellite or ground-based instruments declines as the solar zenith angle (SZA) increases, especially beyond 75 degrees, resulting in many instances of albedo values that exceed the expected maximum clear sky snow albedo of 0.84 measured byKonzelmann and Ohmura (1995). Here, we limit problematic data by focusing on the June–August period when SZA is minimal.
It’s something of a misconception that China industrialization has increased black carbon emissions.
we calculate that BC emissions in China in 1995 were 1342 Gg, about 83% being generated by the residential combustion of coal and biofuels.
http://www.sciencedirect.com/science/article/pii/S1352231001001790
Rather, the reverse is true. As people move from traditional dwellings to modern housing in cities with electricity, BC emissions decrease.
Do this not indicate that the natural system is functioning in a normal manner – the solids, be they from human activities or Volcanoes, are being washed off the land where rain falls and then buried in the bottom of lakes or deltas. In the case of Ice areas the dark melts the ice again taking the dark materials to the bottom where they will be buried in new ice and/or deposited on the ocean floor and buried in silt and other normal ocean heavy materials.
Again we silly humans try to make a big deal out of a 100 year cycle – in geological time it is a nano second.
I imagine Anthony is at least partially right, that albedo is affected by coal plants. I’m glad to know its not affected by anything man is doing (lol). What kind of animals are making the coal dust anyway?
In addition to the coal dust, I would imagine that the overall warming of Greenland and the resulting “melting ponds” don’t help albedo either. Boy……if we can just keep the animals from making the coal dust AND the melt ponds, we’ll be good as gold.
Rob L says:
July 22, 2012 at 9:34 am (Edit)
The graphs is normalised in Feb to precisely the same value, yet still ends up with 4% variation by november, when it must be totally snow covered again.
This instrument obviously has relatively large errors compared to the data presented, so lets not panic or draw unwarranted conclusions about soot or meltwater just yet.
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Problem is you would expect any error to be present at all altitudes. And you have to contend with and explain the actual ground truth calibration data.
Anyone who wants to claim errors in the data must explain why the errors are confined to an altitude. Anyone who wants to explain this by soot, must explain why soot effects confine themselves to a specific altitude.
Not impossible, but arm waving wont make these explainations fly. Real science boys. step up and do some. formulate a testable hypothesis and test it
Bill Yarber says:
July 22, 2012 at 9:30 am (Edit)
Anthony
Is it possible there are to sensors for the two altitude readings? Looks like a failing sensor.
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there is one sensor. it measures returns from the surface. Altitude is already mapped for every 90 meters on the planet, and finer meshes than that are available, depending on the region.
Read the papers, especially on albedo calculations.
Bill Illis says:
July 22, 2012 at 6:30 am (Edit)
Greenland summit webcam
http://www.summitcamp.org/status/webcam/
Looking awfully white.
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Fails:
1. trying to read albedo from a camera with an unknown calibration, without compensating
for the scattering effects between the sensor and the target. failure to account
for the angle between the camera and the target. But yes, it “looks white”
fortunately scientists don’t use web cams to figure out reflection of incoming SW
radiation using web cams
2. Summit is at 10,500 ft. The loss of albedo there is not as dramatic as the loss
at lower altitudes.
Next.
Bill Illis says:
July 22, 2012 at 6:20 am (Edit)
You can get Albedo charts and values from here.
http://neo.sci.gsfc.nasa.gov/Search.html?group=72
When I first read about this a few weeks ago, I did some checking. There is a big decline in central Greenland Albedos in the curent year, not so much previously.
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That link is to the 16 day product
“The daily MOD10A1 product is chosen instead of the MODIS MOD43 or MCD43 8-day products to increase temporal resolution. ”
http://modis-snow-ice.gsfc.nasa.gov/?c=MOD10A1
users guide
http://modis-snow-ice.gsfc.nasa.gov/?c=userguides
It is not the ice (delayed reflection of the past) it is the Arctic atmospheric pressure oscillation which foretells the future of the temperature changes
http://www.vukcevic.talktalk.net/NAO-SST-ea.htm
Well it is an event to watch out for and I do believe that the culprit is the soot ; the evidence points that way.
But ice is not white. Crystals of water are white, Some crystals whiter than others.
or folks can start with this paper.
http://www.the-cryosphere-discuss.net/6/593/2012/tcd-6-593-2012.html
Abstract. Greenland ice sheet mass loss has accelerated in the past decade responding to combined glacier discharge and surface melt water runoff increases. During summer, absorbed solar energy, modulated at the surface primarily by albedo, is the dominant factor governing surface melt variability in the ablation area. Using satellite observations of albedo and melt extent with calibrated regional climate model output, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback in twelve summer periods beginning in 2000. We find that while the albedo feedback is negative over 70 % of the ice sheet, concentrated in the accumulation area above 1500 m, positive feedback prevailing over the ablation area accounts for more than half of the overall increase in melting. Over the ablation area, year 2010 and 2011 absorbed solar energy was more than twice as large as in years 2000–2004. Anomalous anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007 enabled three amplifying mechanisms to maximize the albedo feedback: (1) increased warm (south) air advection along the western ice sheet increased surface sensible heating that in turn enhanced snow grain metamorphic rates, further reducing albedo; (2) increased surface downward solar irradiance, leading to more surface heating and further albedo reduction; and (3) reduced snowfall rates sustained low albedo, maximizing surface solar heating, progressively lowering albedo over multiple years. The summer net radiation for the high elevation accumulation area approached positive values during this period.
Picking out some features
Concerns about the sensor? compared to ground truth fellas.
“We compare MOD10A1 albedo with GC-Net albedo for the 2000–2010 time period
at 17 GC-Net sites within the 550–3250m elevation range.”
Do they argue that its co2?
4.4 Important role of NAO in 2000–2011 surface climate trends
also interesting.. how much snow falls and where
4.5 Ice sheet albedo feedback
5.5 Summer NAO importance
Some interesting things. No suggestions that soot isolates itself to a particular altitude regime, but fire away.. testable hypothesis welcomed.
Billy
“Obviously, a few hours (maximum of 6 since the other recorded temperatures that day were below freezing) above freezing will alter the surface characteristic of the snow and probably led to glazing the snow surface.”
That is one of the mechanisms they discuss. The others are related to weather patterns, the amount of fresh snow that falls, when and where, and snow crystal metamorphosis.
it could be leprachuans.
AndyG55 says:
July 21, 2012 at 9:43 pm
I mean, we seem to assuminng that the black is because of something black, rather than just a lack of reflected light of the bottom.
Has anyone slung a bucket into one of these melt lakes to sample what stuff is at the bottom which looks black? Is it industrial soot, wildfire soot, local rock dust from glaciers or just an optical effect?
Steven Mosher says:
July 22, 2012 at 2:12 pm
“Not impossible, but arm waving wont make these explainations fly. Real science boys. step up and do some. formulate a testable hypothesis and test it”
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As long as we are getting so worked up over short term data fluxes,
the leprachuans theory is starting to sound as good as any.
Working on the capture routine, I imagine they might need water-boarding ?
@Steve Mosher,
While I do agree that the summer albedo drop is probably a function of summer melting, it’s still only about 12 years of data with one anomalous summer in that 12-yr time series. The GRACE measurements upon which the accelerating ice loss claims are based are heavily dependent on the GIA. While not as large as Antarctica (where the GIA’s margin of error is nearly as large as the asserted ice loss), GIA variations can result in totally different ice loss values… And the GRACE time series isn’t any longer than the MODIS time series.
Wu et al., 2010 determined that the GIA commonly assumed for Greenland was way too high and that the 2002-2008 ice loss rate was 104 Gt/yr rather than the oft cited 230 Gt/yr. Even at 230 Gt/yr, it would take 1,000 years for Greenland to lose 5% of its ice mass.
Riva et al., 2007 concluded that the ice mass-loss rate in Antarctica from 2002-2007 could have been anywhere from zero-point-zero Gt/yr up to 120 Gt/yr. Dr. Riva recently co-authored a paper in GRL (Thomas et al., 2011) which concluded that GPS observations suggest “that modeled or empirical GIA uplift signals are often over-estimated” and that “the spatial pattern of secular ice mass change derived from Gravity Recovery and Climate Experiment (GRACE) data and GIA models may be unreliable, and that several recent secular Antarctic ice mass loss estimates are systematically biased, mainly too high.”
So… We have barely a decade’s worth of data and no idea if the modern melt rates and albedo changes are anomalous relative to the early 20th century Arctic warming, Medieval Warm Period or any of the other millennial-scale Holocene warming periods.
There is an ongoing project to measure the effect of BC on Arctic ice albedo.
Here is a presentation from the group. Many uncertainties. But some studies show large reductions in BC over the last 20 years or so. One study points to south Asia as a major source.
http://www.atmos.washington.edu/sootinsnow/PDF_Presentations/UW_ATMS_Arctic_Snow_Feb2007.pdf
Lets tally a score.
we’ve had people questioning the sensor.. without checking the validation data: Fail
we’ve had people claiming they know it is soot: without one shred of empirical evidence from the sites and with no explanation of how soot affects one altitude more than others: fail
we;ve had people point to summit web cam as a measure of albedo: fail
we’ve had people point to the wrong albedo database: fail.
and now, rather than say.. “hey we don’t know, lets read the paper which is freely posted”
we have people saying.. we dont know it its unprecedented,
GUESS WHAT. it doesnt matter one whit whether this has happened before. It most likely has.
The MWP was probably warmer, the holocene was probably warmer. Neither of those matter.
GHGs warm the planet. The question is how much. A warmer MWP means our problem is worse, not easier to handle.
@Steve Mosher,
The assertion that the not unprecedented nature of the modern warming makes our problem “worse,” is simply baseless.
You are correct that GHG’s contribute a net warming effect and that we do not know the net warming effect. But we have no real evidence that the modern warming is any warmer than previous millennial-scale Holocene warming periods. The only well-established difference between this warming period and the previous 10-12 is human industrialization. If we can’t tell the climatic difference between this warming and the previous ones, we can’t even honestly assert an anomaly, much less ascribe a cause.
Furthermore, there are now dozens of peer-reviewed papers documenting that the previous Holocene warming periods were associated with much higher CO2 levels than indicated by Antarctic ice cores. Plant stomata reconstructions clearly establish that Holocene CO2 levels have routinely been above 300 ppmv, possibly as high as 360-390 ppmv. So, not only do we not know if there is a genuinely anomalous warming, we might only be responsible for less than half of the GHG rise.
@ur momisugly Steven Mosher , sorry I agree with Mr. Watts on this one; please tell me why you believe it is not soot from various sources.
Steve Mosher makes very good points in his first paragraph – we really are not approaching this very scientifically.
Re the last paragraph:
1. The MWP was probably warmer, the holocene was probably warmer.
2. Neither of those matter.
3. GHGs warm the planet.
4. The question is how much.
5. A warmer MWP means our problem is worse, not easier to handle.
I agree/understand points 1 to 4.
But the point/argument in point 5 evades me…
Steven Mosher says: July 22, 2012 at 5:05 pm
“GHGs warm the planet. The question is how much”
My answer to your “how much?” is “not much”.
The global warming from pre-1900 to ~1940 exhibits a similar slope to the global warming from ~1975 to ~2000 – this says “not much”.
The global cooling from ~1940 to 1975 also says “not much”.
The absence of global warming for ~10 to 15 years since ~2000 also says “not much”.
Finally, the imminent global cooling that we predicted in 2002, to start by 2020 to 2030 will also say ”not much” 🙂
OK – I’m assuming our global cooling prediction will happen, probably before 2020. The basis for my confidence is that all my other 2002 predictions in climate science and energy have already been proven correct. The imminent cooling one was fairly easy compared to some of the others.
To quantify, a doubling of atmospheric CO2 from ~280ppm to 560, should this happen, will result in net global warming of less than 0.3C.
The black stuff on the bottom of the lakes is carbon dust and pollution in general… but not from one year, but several decades
Why then is the albedo only now ‘off the charts’. This is not right.
I’m afraid Anthony is wrong on this issue. See my link above about 83% of BC emissions from China being from domestic and biofuel sources, and see figure 9 at the link below that shows global BC emissions from coal burning peaked as early as the 1920s and have certainly declined since the 1950s.
http://www.c2es.org/docUploads/black-carbon-12-16-09.pdf
Further, very little of China emissions will reach Greenland.
IMO, the likely cause of the albedo changes is an increase in solar insolation causing BC and other particulate matter to accumulate on the surface. Although other effects may be at work, like changes in ice reflectivity from melt refreeze.
The same effect is causing (at least in part) the disproportionate faster melt of older sea ice compared to newer sea ice.
Or how about the simplest explantion – that the planet is warming due to greenhouse gas emissions, as predicted by climate scientists since at least as far back as the 1970s.
The Greenland ice cap melt and the arctic sea ice melt (and receding glaciers in Iceland, etc) are more likely to be a response to higher ocean and air temperatures.
Towns in the west of Greenland have generally been recording well above average temperatures during this summer and a new absolute record high was set in May.
James Abbott says:
July 23, 2012 at 3:58 am
Or how about the simplest explantion – that the planet is warming due to greenhouse gas emissions, as predicted by climate scientists since at least as far back as the 1970s.
It appears the only simplicity here is your (lack of) understanding.