Greenland ice melt overestimated due to satellite data algorithm issue

This is an interesting admission:

The melt extent algorithm used by Greenland Ice Sheet Today has been overestimating the melt extent, and as a result, daily images posted on this site in February and March may have indicated melt where none occurred.

This makes you wonder what other kinds of issues remain undetected in the satellite data. NSIDC has had to issue corrections in the past, when it was pointed out that their data and reality didn’t match. – Anthony

From NSIDC: An early spring re-calibration for melt detection

The algorithm for the Greenland Ice Sheet Today daily melt extent has been revised to account for unusually warm winter snow layers and residual meltwater deep in the snow. Meltwater from last summer’s intense melt season did not completely re-freeze through at least mid December. The adjusted algorithm shows greatly reduced melt extent for early 2013. This much lower extent is more consistent with available weather and climate records.

Melt extent and distribution

Figure 1. These images show cumulative melt extent before the algorithm correction (left) and after the correction (right). A few areas indicating one to two days of melting in southeast Greenland remain in the revised map. The red dot shows the location of the Danish AWS. Credit: National Snow and Ice Data Center – Click for hires image

As shown in Figure 1, the adjustment to the algorithm resulted in fewer melt days than previously indicated. The revised image at right shows new surface melting in 2013 in a few small areas along the central southeastern Greenland coast, within the region of earlier spurious melt signals but greatly reduced.

Conditions in context

Figure 2. This image shows air temperature anomaly for Greenland for the period December 2012 to February 2013. Reds and oranges indicate higher than average air temperatures. The temperatures shown are at approximately 1,500 meters (5,000 feet) in altitude, appropriate for coastal Greenland regions. However, central Greenland is above this altitude, and values shown there do not represent the true surface conditions well. Credit: National Snow and Ice Data Center courtesy NOAA ESRL Physical Sciences Division

Temperatures in Greenland have been higher than average this winter, with air temperatures near the coast averaging 2.0 to 3.5 degrees Celsius (4 to 6 degrees Fahrenheit) warmer than the 1981 to 2010 average. This has in part been a result of the persistent circulation pattern for the Arctic this winter, characterized by a negative Arctic Oscillation (AO). The AO is a measure of the intensity of the general pattern of low pressure over the northern high latitudes. A negative AO indicates higher-than-average pressures near the North Pole, allowing more frequent southward cold air outbreaks, and more intrusions of warm air masses from higher temperature areas. Despite these anomalously high temperatures along the Greenland coast, temperatures were not high enough to result in melting.

Adjusted algorithm and melt images

Figure 3. This plot shows surface air temperature at a PROMICE on-ice Automated Weather Station (AWS) near the southeastern Greenland ice sheet edge for early 2013. Temperatures did not exceed freezing at this site. Data from PROMICE were provided by the Geological Survey of Denmark and Greenland (GEUS) and are freely available. Credit: National Snow and Ice Data Center and J. Box, Geological Survey of Denmark and Greenland

The melt extent algorithm used by Greenland Ice Sheet Today has been overestimating the melt extent, and as a result, daily images posted on this site in February and March may have indicated melt where none occurred. While the algorithm was indicating some coastal melt in February and early March, a comparison with weather data for Nuuk (the Greenland capital city, located along the southwest of the island) and data from the Programme for Monitoring of the Greenland Ice Sheet (PROMICE) suggested these might be spurious melt readings. The local Automated Weather Station (AWS) data from a glacier along the southeastern coast (the Mittivakkat glacier AWS, shown by a red dot in Figure 1; data in Figure 3) indicate that the air temperature did not rise to the melting point (0 degrees Celsius, or 32 degrees Fahrenheit) in February or early March.

Figure 4. A model of the snowpack conditions indicates residual liquid water in the deep snowpack in southeastern Greenland. Credit: National Snow and Ice Data Center and X. Fettweis, Université de Liège, Belgium

During this period, starting around mid-February in southeast Greenland, the brightness temperatures in the upper few meters of the snowpack were 2 to 10 degrees Celsius (4 to 18 degrees Fahrenheit) higher than those observed during any other year in the 34-year record (1979 to 2012). While surface melt is not unprecedented in Greenland near the coast in February and March, the totals posted prior to March 14 were a result of these unusual snow temperature conditions, and not ongoing surface melt. This winter has seen unusually warm snow at depth on the ice sheet, following the intense melting that occurred last summer.

The melt detection method, based on passive microwave emissions, is primarily sensitive to near-surface conditions, but has some input from the snowpack down several meters (10 to 20 feet). Heavy snow fell during the relatively warm winter, burying and insulating deeper snow. This contributed to anomalously high temperatures for the uppermost layers of snow this winter. Additionally, models based on snowpack properties suggested that some 2012 meltwater remained unfrozen at 5 meters depth (approximately 16 feet) in mid-December. The model results are consistent with observations from JAXA’s AMSR-2 sensor.

The algorithm was adjusted by combining the trend of observed brightness temperatures with a model of the expected microwave emission in the channels used for melt detection (the SSM/I sensor’s 37 GHz Horizontal polarization channel). This adjustment is generally performed every year in March to calibrate the melt detection thresholds. However, because of the unusual condition of the snowpack, the adjustment needed to be made much earlier than ever before.

Further information

Fettweis, X., M. Tedesco, M. van den Broeke, and J. Ettema, 2011. Melting trends over the Greenland ice sheet (1958-2009) from spaceborne microwave data and regional climate models. The Cryosphere 5, 359-375, doi: 10.5194/tc-5-359-2011.

Programme for Monitoring of the Greenland Ice sheet (PROMICE)

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87 Responses to Greenland ice melt overestimated due to satellite data algorithm issue

  1. So the Ice that was melting in Feb, was really not melting, and in fact might have been increasing in mass… Our Bad.

  2. I believe if you changed all the catastrophic man-made global warming rhetoric, to a reference of the worldwide economy, rather than a reference to worldwide climate, the alarmists would be 100 percent accurate.

  3. Niff says:

    So the images are…..photoshopped?

  4. Lawrie Ayres says:

    It would appear the knowledge that an increasingly large number of climateers outside the government paid circle are keeping a careful and expert eye on their “data” is having a very positive effect. Shoddy work erring on the side of the warmers is no longer acceptable and is quickly identified and, encouragingly, is now being corrected. Kudos to all you honest scientists.

  5. Lank remembers says:

    The Washington Post
    “The Arctic Ocean is warming up, icebergs are growing scarcer and in some places the seals are finding the water too hot, according to a report to the Commerce Department yesterday from Consulafft, at Bergen, Norway

    Reports from fishermen, seal hunters, and explorers all point to a radical change in climate conditions and hitherto unheard-of temperatures in the Arctic zone. Exploration expeditions report that scarcely any ice has been met as far north as 81 degrees 29 minutes.

    Soundings to a depth of 3,100 meters showed the gulf stream still very warm. Great masses of ice have been replaced by moraines of earth and stones, the report continued, while at many points well known glaciers have entirely disappeared.

    Very few seals and no white fish are found in the eastern Arctic, while vast shoals of herring and smelts which have never before ventured so far north, are being encountered in the old seal fishing grounds. Within a few years it is predicted that due to the ice melt the sea will rise and make most coastal cities uninhabitable.”

    * * * * * * * * *
    I apologize, I neglected to mention that this report was from November 2, 1922, as reported by the AP and published in The Washington Post – 90 years ago.
    Yep – ice melt was a tad overestimated back then too – and without the help of satellites!!

  6. Pingo says:

    Now try to spot a watermelon saying what good news this is! More difficult than finding an unbroken hockey stick..

  7. Village Idiot says:

    Proof (if we needed it) that the “Unprecedented Greenland Ice Sheet Surface Melt” of 2012 didn’t really happen
    http://www.nasa.gov/topics/earth/features/greenland-melt.html

  8. tokyoboy says:

    Algorithms and models, not the reality, are über alles in the so-called climate science.

  9. tty says:

    One wonders why they didn’t check the weather at Kulusuk instead. Kulusuk is right in the middle of the supposed snowmelt area while Nuuk 400 is miles away on the other side of the icecap (and weather is often very different on the east and west coasts).

    Here is weather for Kulusuk airport:
    http://www.tutiempo.net/en/Climate/Kulusuk_Lufthavn/02-2013/43610.htm

    February: average temperature – 3,6, average maximum -1,1, average minimum -6,4, all Celsius.
    Nine days with maximum above freezing, none with minimum above freezing, seventeen days with snowfall. Which means that there was certainly some daytime snowmelt, but that except for evaporation it refroze next night.

  10. Rational Db8 says:

    @ Lank remembers says: March 21, 2013 at 11:20 pm

    Great post! Thanks for reminding us.

  11. Gary Hladik says:

    As with other areas of science, the devil really is in the details. Kudos for catching this error, now find the remaining bugs (yes, there are more).

  12. Rational Db8 says:

    If Greenland is loosing all this ice over the past 30+ years, I’d dearly love to know how they explain the Glacier Girl.

    For those here who might be unfamiliar, it’s easy to find the story online, and it’s truly fascinating. Essentially back during WWII, a small squadron of fighter planes had to ditch on Greenland. On the glaciers. About 50 years later, they went back and dug down through about 268 feet of ice to get to one of the P-38 fighters. They took her apart down in the hole, lifted her out piece by piece, Then they moved her to a more conducive location, put her back together and flew her.

    Soooooo, to the researchers and scientists who think there’s been so much global warming causing huge ice melts…. just how the heck did a plane on the surface wind up buried under 268 ft. of snow and ice accumulated over those 50 years, during which so much of this global warming occurred????!!

  13. Here we go again. Greenland ice melt over stated. Another body blow to the warmist’s creed.

  14. David, UK says:

    O.T., but in other news, heavy snow has fallen overnight throughout much of the UK, and continues to fall – and fall FAST. It’s a winter wonderland outside my window right now – and we’re three weeks into March! But I know it must be an illusion, because these days children just don’t know what snow is, because it NEVER snows these days. Yep, I’ll be wearing my shorts and Hawaiian shirt as is befitting for these warmer times.

  15. DavidS says:

    Meanwhile in the UK spring of 2013, children still don’t know what snow looks like.

    sarc

  16. SØREN BUNDGAARD says:

    Al Gore-rithm issue;)

  17. richard verney says:

    Yet another example of a data set not fit for purpose.

    Once again, the ‘error’ operating in the AWG proponents’ favour.

    Guess, no surprise there. I share the sentiments expressed by Lawrie Ayres (March 21, 2013 at 10:49 pm) that being held up to scrutiny on the web is having some positive effect.

  18. JDN says:

    I remember commenting on a WUWT story a few years ago that someone needs to do spot checks on sea ice “data” from overflights. Is that going on? I look at the variation in sea ice coverage between algorithms, and the difficulty of figuring out what is ice vs. not ice, and I wonder how long until we find out that the Barents sea isn’t quite as ice-free as sea ice satellites make them to be.

    Speaking of seeing things, I ran across the Dogger Bank incident (http://en.wikipedia.org/wiki/Dogger_Bank_incident) where the Russian navy destroyed British fishing boats because they thought they were Japanese. There was also a line in there about the American navy being so spooked by torpedoes that they fired at “ocean swells, trains on land, and rocks along the coastline, believing them to be enemy torpedo boats”. Just saying, it doesn’t require a computer to see things that aren’t there or vice versa, but computers help.

  19. thomam says:

    WIth the talk of all our “unseasonable” snow in the UK, I observe that it was my stepdaughter’s 15th burthday on Tuesday of this week and it has now snowed on 13 out of her 15 birthdays. But I suppose the plural of anecdote is not data…

  20. Louis Hooffstetter says:

    On March 22, 2013, the third day of spring, it’s literally freezing in the Carolinas. Yet somehow Greenland is melting!

    Climastrology does it again!

  21. tobias says:

    I just won a bet here in BC Canada “against” a warmer (50 lat) , Lived here for 40 years bet him snow at least twice before March 19 ( It snowed 4 times.) Where does this report fit in anyhow, “Greenland ice melt overstated”,… in February ??. What else is new from their corner of the “debate”.
    They are in full retreat , only theirs is real in contrast to the glaciers on Greenland.

  22. Ian W says:

    One would have thought that there would be some automated validation of these satellite metrics. There are numerous automated ground observation stations even in the arctic ocean there are automated buoys reporting weather and temperature data. There could be a rigorous cross check between the sensors that would have shown up inaccuracies very rapidly. Similarly for ocean temperatures now there are ARGO floats reporting SST they should be cross checked against satellite SST. As it is these ‘climate scientists’ take weather reports and rush off ito their pet politicians to trigger more non-science policies.

  23. Back in the days when I was naive i.e before I started to investigate the historic claims of climate change scientists-I would have believed the Greenland ice melt (and many other climate related things) was because someone had actually physically OBSERVED it. It seems that most climate science these days comes from models and maths and the original observed quality raw data is missing.

    Incidentally, the warmest two consecutive decades in Greeland remain the 1930′s and 1940′s. We will have to wait until 2020 to see if the current spell of warmer than average weather beats it
    tonyb

  24. Dr. John M. Ware says:

    Last year March here in Virginia was very warm, though not quite a record as I recall. This year is very different–cold, occasionally snowy, dreary. Two days ago it got to 62 degrees F here, the first day in the 60s this March, and likely the last according to the local weatherfellas. Yesterday our Weatherbug said the high was 46, but that was at midnight; by dawn it was 30 degrees, and by 7 a.m. it was 26 and snowing briskly. Not much stuck because the ground was so warm, but the grass and cars did get a white coating for a while. The high for the actual daylight was 35 with a brisk wind, making garden work impossible. How I have wished for just enough global warming to get some work done! Seeds need planting, beds need cleaning, etc., etc. Not in the outlook–more snow likely by Monday morning.

  25. johnmarshall says:

    Those damn temperature anomalies actually tell you nothing. It may be 3Cwarmer than a, supposed, average but was that above or below freezing, 0C?
    The satellites also have problems with the many melt ponds that form on sea ice and report these as clear water. They also have problems with broken ice which again is reported as clear water.
    Perhaps scare reports about the disappearing sea ice are not as real as thought.

  26. For johnmarshall: Nothing about the warmists scare reports is real by definition!

  27. Ian says:

    I think the conversion is incorrect re Celsius to Fahrenheit ..being Canadian, I recognized this immediately :
    ” During this period, starting around mid-February in southeast Greenland, the brightness temperatures in the upper few meters of the snowpack were 2 to 10 degrees Celsius (4 to 18 degrees Fahrenheit) higher than those observed during any other year in the 34-year record (1979 to 2012). ”

    2 Degrees C = 35 F
    10 degrees C = 50 degrees F
    however, if they meant the other way around.
    4 degrees F = minus 15 or ( -15 C)
    18 degrees F = minus 7 C or ( -7 C )

    so which did they mean….

  28. Richard Day says:

    Our algo was off but we’re still believers in the church of global warming. By the way, we need a 14% increase in our funding. Bonuses and such.

  29. Jimbo says:

    For newbies obsessed that something is wrong in Greenland please take a look at the following. It looks like natural cycles to me.

    Abstract
    ….The record indicates that warmer temperatures were the norm in the earlier part of the past 4000 years, including century-long intervals nearly 1°C warmer than the present decade (2001–2010). Therefore, we conclude that the current decadal mean temperature in Greenland has not exceeded the envelope of natural variability over the past 4000 years, a period that seems to include part of the Holocene…..
    [Takuro Kobashi et. al.]
    ——-
    Abstract
    An aerial view of 80 years of climate-related glacier fluctuations in southeast Greenland
    …………the recent retreat was matched in its vigour during a period of warming in the 1930s with comparable increases in air temperature. We show that many land-terminating glaciers underwent a more rapid retreat in the 1930s than in the 2000s,……
    [Anders A. Bjørk et. al.]
    ——-
    Abstract
    “…the rate of warming in 1920–1930 was about 50% higher than that in 1995–2005….”
    [Petr Chylek et. al.]
    ——-
    Abstract
    “…The annual whole ice sheet 1919–32 warming trend is 33% greater in magnitude than the 1994–2007 warming….”
    [Jason E. Box et. al.]
    ——-
    Abstract
    “…The warmest year in the extended Greenland temperature record is 1941, while the 1930s and 1940s are the warmest decades….”
    [B. M. Vinther et. al.]
    ——-
    Abstract
    The State of the West Greenland Current up to 1944
    “….It is found that warmer conditions existed during the decade of 1880, followed by a colder period up to about 1920, when the present warm period began. The peak of the present warm period appears to have been reached in the middle 1930′s,…..”
    [M. J. Dunbar]

    On last year’s ‘unprecedented’ melt it appears to have been caused by soot according to the Guardian. Though in happened in 1889.

    Rediscovered photos reveal Greenland’s glacier history
    Cache of historical Arctic sea ice maps discovered

  30. jayhd says:

    This may seem like a stupid question, but don’t these “scientists” and computer “experts” validate their satellite data, images and models by actually going to a sampling of sites and getting real data and photographs? Without validation, what these people are doing is not “science”, it’s computer games!

    By the way, I’ve become real familiar with the errors occurring in the GISS maps used by county planners and the various on-line mapping services. Errors such as drainage ditches labeled as roads, large farm equipment labeled as barns or sheds or silos, and so on. The GISS people don’t do a good job of validating their programs either.

  31. Marcos says:

    i’m confused. why are satellite sensor results being put into a computer model to come up with its ‘data’? shouldn’t the sensor data, oh i dont know, be the data?

  32. PaulH says:

    So “Greenland Is Melting! Melting!” was front page news. Will this correction appear on Page 1, or will it be buried somewhere in the classifieds?

  33. starzmom says:

    For another slightly OT anomalous weather update, here in eastern Kansas we are expecting 9-12 inches of snow for Palm Sunday. At this rate my easter dress will be heavy wool with boots. And the forsythia have yet to show themselves.

  34. Owen in GA says:

    Ian says:
    March 22, 2013 at 3:55 am
    I think the conversion is incorrect re Celsius to Fahrenheit ..being Canadian, I recognized this immediately… :

    Ian, I think they are talking differences in temperature rather than absolute readings. If something is 2C warmer, it is 18/5 F warmer (3.6F). You interpreted it to say the snow was 2 to 10 degrees C which is an impossibility as it would have melted.

  35. Scott says:

    Jayhd says
    march 22, 2013 at 4:59 am

    … but don’t these “scientists” and computer “experts” validate their satellite data …

    A couple things about validation, to be a good validator you have to be skeptical of everything and not afraid of finding something wrong and potentially embarrassing to your organization. So you really can’t be the same guy who designed the satellite or comes up with the data … you are too close and would have too much to lose. When you are a validator you take off your “team player” hat for a while. So I can see how that’s a problem for the global warming community.

    But there is a way around this. I’ve had a few validation projects and we couldn’t get half the guys to leave their computers and get out in the plant and find something we didn’t already know. They wanted to validate everything from their computer rather than walking a quarter mile in the plant. Really frustrating. They avoid the tough part about validating by not really validating.

    Guys like Anthony should be the validators, not the scientists or computer experts.

  36. numerobis says:

    “This may seem like a stupid question, but don’t these “scientists” and computer “experts” validate their satellite data, images and models by actually going to a sampling of sites and getting real data and photographs?”

    Isn’t that what the story says they did? They noticed the model was wrong by checking measurements on the ground; so they fixed the model.

  37. ferd berple says:

    Jimbo says:
    March 22, 2013 at 4:29 am
    Cache of historical Arctic sea ice maps discovered
    ===============
    The old nautical charts from England’s golden age of exploration show that sea levels have not risen anything like what is currently believed. These charts are still highly accurate even today, and most of the modern nautical charts are simply copies of these older charts, with corrections for wrecks, rocks missing in the original surveys, and datum adjustments for GPS.

    Very few areas worldwide have ever been re-surveyed due to the high cost. Yet, almost universally, if a rock was shown on the charts as awash at low tide 200-300 years ago, it is still awash at low tide today. If sea levels were truly rising, these rocks should no longer be visible at low tide. Nowhere on the charts is a datum adjustment for “sea level rise”.

    Which is very strange. These charts are vital to preventing loss of ships and lives. You would think that if sea level rise was real, these charts would have been updated to reflect this.

    The reason they have not is quite simple. If the charts were adjusted to show sea levels rising when it has not, then this would result in water depths being reported as deeper than they really are. This would result in ships running aground when they thought they were safe, resulting in the loss of ships and lives.

    Thus, nautical charts are one of the best sources of information on sea level rise over the past 2-3 hundred years, and why to this date they have not been used to calibrate sea level rise. Instead we see endless tidal gauges mounted on sand and mud, or sea shells or tea leaves used a proxies.

  38. Admad says:

    Am I missing something here? Why would something which is readily observable have to be “modelled”?

  39. beng says:

    The cold weather in Scandinavia has something to do w/the Greenland east coast. Easterly winds from there have been crossing the N Atlantic to hit Greenland. That air isn’t Arctic by that time — not even below freezing.

    It’s called weather.

  40. Billy Liar says:

    Can some genius at NSIDC please generate an outline of the 1500m contour on Greenland, place it on their anomaly map (Fig 2) and set the color inside the contour to white.

    The anomaly map would then appear a tad more honest: showing fictitious anomalies below the surface of the ice is somewhat bizarre to say the least.

  41. This case shows up the folly of overreliance on algorithms, statistics and computer models, and not paying enough attention to real world data.

    This was illustrated well with the issue of GHCN temperature adjustments in Iceland. In 1965, Iceland underwent a drastic drop in temperatures. The cold spell lasted well into the 1970′s, and was so severe that agriculture and fishing suffered hugely, leading to mass unemployment and 50% currency devaluation. This time even had a name, “The Sea Ice Years”, and has been well researched by proper scientists.

    Yet, the GHCN algorithm interpreted this as a data glitch and adjusted the drop in temperature out of existence. GHCN still refuse to accept their adjustments are faulty.

    There’s more on the background to the Sea Ice Years here.

    http://notalotofpeopleknowthat.wordpress.com/2012/10/30/ghcn-temperature-adjustments-in-icelanda-closer-look-at-stykkisholmurpart-ii/

  42. Chris4692 says:

    Village Idiot says:
    March 21, 2013 at 11:37 pm

    Proof (if we needed it) that the “Unprecedented Greenland Ice Sheet Surface Melt” of 2012 didn’t really happen

    (Others as well)

    The article says no such thing. It applies to recalibrating 2013 data, not 2012. It even refers to the water from the ice melt of last summer remaining unfrozen under the surface.

    Although there are reasons to think that last summers melt was not unprecedented, this article is not one of them.

  43. ferd berple says:

    ps: there is good reason to increase water depth on nautical charts if sea level rise is occurring. Increased water depth opens up new sea-lanes and can save millions in costs. It is not unusual for ships to travel in areas where the difference between a safe passage and running aground is less than the difference between high and low tide for that day.

  44. ferd berple says:

    Paul Homewood says:
    March 22, 2013 at 6:53 am
    Yet, the GHCN algorithm interpreted this as a data glitch and adjusted the drop in temperature out of existence. GHCN still refuse to accept their adjustments are faulty.
    ===========
    Very interesting. This shows the problems in adjusting temperatures to try and improve signal quality. What the computer thinks is noise may well be signal, and what the computer this is signal may well be noise.

    This is in some way similar to the famous hockey stick, where in an attempt to amplify the signal in tree rings via “calibration” what actually happened was an amplification of noise. Since this noise was random it gave the appearance that temperatures had not changed for 1000 years and we all got the shaft as a result.

  45. John F. Hultquist says:

    jayhd says:
    March 22, 2013 at 4:59 am
    “. . . actually going to a sampling of sites and getting real data . . .

    Such real data was called ‘ground truth’ and getting such was called “ground truthing.”
    I remember it well, much like a beer for 25¢.

    http://en.wikipedia.org/wiki/Ground_truth

  46. knr says:

    How lucky do you have to be to find all the ‘mistakes’ work in favour of the ideas your pushing ?

  47. Caleb says:

    RE: Paul Homewood. Thanks for the link. I like your site.

  48. Darren Potter says:

    Now where is Mr. CostCo who was defending NASA’s Greenland ice loss and sea level measurements via satellite (http://wattsupwiththat.com/2012/12/03/why-ice-loss-and-sea-level-measurements-via-satellite-and-the-new-shepard-et-al-paper-are-highly-uncertain-at-the-moment/)
    doubting possible issues of unknown errors and unaccounted for drift with remarks like:
    “I have technical knowledge in the satellite and instrument domains …”

    Mr. CostCo: “Basically you’re insinuating that the glaciological community as a whole does not know how to assess errors and neither does Nature/Science etc”

    Wonder what Mr. CostCo would deem failing to properly assess errors that allowed a hosed algorithm involved in measuring Greenland’s Ice Sheets to go undetected until after Shepherd et al paper was touted? Possibly the old ‘Nothing to See Here, Move Along’?

  49. Steve from Rockwood says:

    Now why didn’t I read this in my local paper? They carried the unprecedented melting story…

  50. J. Gary Fox says:

    Great story with details on “Glacier Girl” … above comment by Rational Db8 on WWII planes buried in Greenland.
    http://www.damninteresting.com/exhuming-the-glacier-girl/

    Do we know which glacier was it that the 8 planes landed on?
    Is it one of the “fast melting” glaciers listed As Rational noted, if so, how did they get buried in 268 feet of accumulated snow in 50 years?

  51. jayhd says:

    Numerobis, testing and validation should be done before the system is fully operational, not after. That eliminates a lot of errors and embarrassment. I’ve been responsible for implementing several large and small accounting systems and these systems were extensively tested before the green light was given. We still experienced some glitches, but they were minor compared to some we found during testing. As one computer systems administrator once told me, “in a million lines of code, an error rate of 1/10th of one per cent is one thousand lines”.

  52. Jim G says:

    Ever wonder why it’s called Greenland and not Whiteland? They once farmed here and raised live stock. I guess global warming ruined that for them. If the ice ever melts they will be back to what it was 1000 years ago and be much better off in the bargain. I am continuously underwhelmed by the knowledge of today’s “scientists”.

  53. Darren Potter says:

    From: (http://wattsupwiththat.com/2012/12/03/why-ice-loss-and-sea-level-measurements-via-satellite-and-the-new-shepard-et-al-paper-are-highly-uncertain-at-the-moment/)
    “New proposal from NASA JPL admits to “spurious” errors in current satellite based sea level and ice altimetry, calls for new space platform to fix the problem.”

    Hmmm, would spending several BILLION dollars on NASA’s new GRASP satellite to provided a TRF of ~1mm – countered a “Greenland ice melt overestimated due to satellite data algorithm” problem? Is a hosed algorithm considered a “spurious” error?
    Come on now, those are irrelevant questions when its Taxpayer $$$ providing the funding!

  54. Steve Keohane says:

    knr says:March 22, 2013 at 7:08 am

    How lucky do you have to be to find all the ‘mistakes’ work in favour of the ideas your pushing ?

    Didn’t you know, climate scientists are the luckiest people on earth. All corrections and biases support their every conjecture. When you are on a mission to save the planet from the dross of humanity, the Force is with you!

  55. Darren Potter says:

    >> Village Idiot says: ” Proof (if we needed it) that the “Unprecedented Greenland Ice Sheet Surface Melt” of 2012 didn’t really happen”
    > Chris4692 says: “(Others as well) The article says no such thing. ”

    True it doesn’t. However, how many times are you willing to go to bat for a Big Government Agency who keeps making Headline grabbing GW claims; only to find out later there are problems with said Agency’s work that make their Headline grabbing total Bovine Scatology?

  56. Owen in GA says:

    Marcos says:
    March 22, 2013 at 5:16 am
    i’m confused. why are satellite sensor results being put into a computer model to come up with its ‘data’? shouldn’t the sensor data, oh i dont know, be the data?

    Marcos,

    The “actual data” is a series of intensity measurements of a set of known wavelengths. The model they are referring to is the one that says “>X_n intensity at Y_n wavelength equals ice at temperature Z”, etc. . The data from the sensor are totally incomprehensible without some underlying model to tell you what the numbers mean. That the model assumptions need to be checked against ground truth more frequently than they are is absolutely without question, but the “raw numbers” have no meaning by themselves.

  57. John W says:

    @Lank or anybody else……do you have a link for that 1922 article? Thanks if you can post it….I want that link!

    I apologize, I neglected to mention that this report was from November 2, 1922, as reported by the AP and published in The Washington Post – 90 years ago.
    Yep – ice melt was a tad overestimated back then too – and without the help of satellites!!

  58. elmer says:

    that Al Gore and his rythms

  59. Dave in Canmore says:

    As anyone who has ever been in the snow can tell you, the more snow depth you have, the more insulation you have. I find it hard to believe this hadn’t ever been accounted for.

    For anyone who skis the backcountry and does avalanche assessment, this is all pretty common stuff. In the mountains where I live, even a freezing rain layer burried under enough insulating snow has the potential to metamorphize due to warmth from the ground changing its crystal structure (even though the air temperature is well below freezing.)

    Seems to be the case here that more insulating snow decreased the temperature gradient between the warm ground and the cold air. Too much insulation means the warm layer never cooled off as much, fooling the satellite. At least that’s what I understand from their release.

    as an OT aside, Its kind of cool in that when there is cold air and shallow snowpack, the cold air meets the warm air from the ground and crystalizes whatever moisture is available. These crystals are very sugary and allow upper layers to slide on them creating avalnche potential. What’s cool is that it’s like a warm ocean front meeting an arctic air mass but all happening within the snow layers. A perfect microcosm of the weather inside the snow layers!

  60. James at 48 says:

    Pixel counting (or not counting) issues. Issue discerning true edges of ice. Fresh snow on top or not. Etc, etc, etc. Just like sea ice remote sensing. Frought with all sorts of pitfalls.

  61. Louis Hooffstetter says:

    Sarc on:
    “The melt detection method, based on passive microwave emissions, is primarily sensitive to near-surface conditions…”

    Well there’s your problem. Locals living along the SE coast got microwave ovens for Christmas.

  62. Robert L says:

    John W says:
    March 22, 2013 at 8:53 am

    @Lank or anybody else……do you have a link for that 1922 article? Thanks if you can post it….I want that link! http://www.damninteresting.com/exhuming-the-glacier-girl/

  63. Jimbo says:

    On the topic of ice we have:
    “Migrating birds leave frozen Germany” (shortly after their Spring arrival)
    http://www.thelocal.de/national/20130315-48551.html#.UUyeBfWQn4w

    “As snow and flooding causes chaos across the country, forecasters have warned that another spell of bitterly cold weather could make this the coldest March in 50 years.”
    http://www.telegraph.co.uk/topics/weather/9948450/The-competition-for-coldest-March-in-50-years.html

    It seems as if Spring is arriving earlier and earlier as global warming takes hold. I’m now waiting for plants to move downhill.

  64. Willis Eschenbach says:

    Rational Db8 says:
    March 22, 2013 at 12:33 am

    If Greenland is loosing all this ice over the past 30+ years, I’d dearly love to know how they explain the Glacier Girl.

    Thanks, Debate. It actually does make sense. Snow falls on the Greenland ice cap. Year after year. It freezes and is compressed to ice. The ice is thick enough that the weight makes it flow out slowly around the edges of Greenland. Note that over the years, the top of the ice cap is gaining new layers of snow each year … while at the same time the old ice from snows thousands of years ago is being squeezed out all around the perimeter of Greenland and breaking off into the ocean.

    Which answers your question about the burial of the Glacier Girl. The ice gain is happening continuously up on the ice cap, year after year—and overall, it is matched by the continuous ice loss around the edges, so the whole is in general equilibrium.

    If the Glacier Girl had never been discovered, in thousands and thousands of years it too would have been squeezed out somewhere along the side of Greenland, and some tourist would have gaped to see the smashed remains emerging from the ice … by the time it was discovered, it had already moved three miles towards the coast.

    w.

  65. numerobis says:

    “Numerobis, testing and validation should be done before the system is fully operational, not after.”

    The claim here is that the underlying assumptions (that the surface would completely freeze in winter) no longer hold, so they had to fix the model to match new realities.

    I hadn’t heard anyone trumpeting about this fictitious early melt; seems the scientists in charge quickly realized there was a bug.

  66. Resourceguy says:

    Science ended sometime around the start of the new millennium and that is the main accomplishment of climate science. It corrupted the rest of science.

  67. Lank remembers says:

    JohnW
    “I apologize, I neglected to mention that this report was from November 2, 1922, as reported by the AP and published in The Washington Post – 90 years ago.”

    If you don’t care to subscribe you can find a copy the original text and commentary here… http://www.snopes.com/politics/science/globalwarming1922.asp

  68. half tide rock says:

    Oh I love it! It is called Field Checking! Calibration! They used to teach it’s importance. Field checking is almost a lost art. If Anthony et al. didn’t field check the surface stations the lemmings would still be chasing the stupid data over the cliff. Ha!

  69. Puppet_Master_Blaster_Master says:

    Anything that Marco Tedesco has had a hand in I, 1 ignore at first and 2 then stay very far away from.

    Marco is all BS and no science.

    Sad

  70. Ooops!
    Honey, I think I shrunk the ice?

  71. CRS, Dr.P.H. says:

    The melt extent algorithm used by Greenland Ice Sheet Today has been overestimating the melt extent, and as a result, daily images posted on this site in February and March may have indicated melt where none occurred.

    What’s the phrase? Oh, yeah, the inconvenient truth….

  72. BruceC says:

    For any one wanting a great site in regards to Glacier Girl (including a small map of crash site), see here;

    http://p38assn.org/glacier-girl.htm

    Not only was it, and all the other aircraft from the squadron, buried under 260 odd feet of ice, it was located over a mile away from where it (they) crash landed.

  73. BruceC says:

    @John W. If you were interested in the 1922 article, you may be interested in this one as well.
    (sorry for the long post as I can’t remember where I got it from, maybe Trove???)

    IS THERE AN OPEN POLAR SEA?

    [From the Boston Traveller.]

    The appearance of Dr Kane’s long expected narrative of Arctic Expeditions will again awaken an interest in the question of an open sea near the North Pole; for his discovery of that sea, with the varied details of every circumstance connected with it, can now be investigated, and the evidence of its continuance to the Pole of the earth be duly weighed.

    The idea of a warmer region than the North Pole, which must be accompanied by open water, and, as a natural consequence, with animal life in a greater abundance than in the permanent ice-belted district further south, is not a new one. More than two centuries ago the appearance of open water in the highest latitudes first suggested it; and, although certain theorists contended against it, the opinion continued to prevail even to our day; and now, although there has been nothing certain of its existence, there have been such accumulative facts, that it only waited the indubitable evidence, such as Dr Kane has presented to establish the theory.

    The Dutch whalemen above and around the island of Spitzburgen have often pushed through the drift ice into open spaces of sea towards the Pole, and Baron Von Wrangel, when forty miles from the coast of Artic Asia, saw, as he thought, a ‘vast illimitable ocean’ and, we doubt not many navigators, without being aware of the fact, have really been in this sea, but who did not dare to venture any further towards the mysterious Pole. Dr Scoresby among others, may be mentioned as one who has been within its area. This veteran Arctic navigator was engaged for more than thirty years in the Greenland fishery, and discovered the coast, and served on the eastern side which bears his name. On this occasion he passed the pack of floating ice, by keeping near the Greenland coast, and found himself in open water beyond. Had he been prepared to pursue his voyage, be might have pushed on nearer the Pole than any navigator before or since, but he did not dare venture beyond a point from which he was uncertain of escaping before the season had passed, and therefore retreated through the pack. Captain Parry in his well-known boat voyage, attempted to cross this floating ice, and was provided for the purpose; but it was unfortunately harder and rougher than he anticipated, and although making progress northward over the drift, he found that it was actually bearing him southward. The projectors of that expedition thought the plan the most feasible one to reach the Pole, entertaining the belief that if they could pass this floating ice they would find an open sea beyond.

    It must here be remarked that in the summer north winds prevail in these seas, and aided by a strong current setting to the south the whole mass of ice accumulated and forced in during the winter, breaks up, and is carried toward the south. This belt of broken ice, or the ‘pack,’ as it is called, forms the only impediment to an approach to the Pole by the North Atlantic Ocean. In the fall when strong southerly winds, such of this pack as remains is again forced towards the Pole, in a measure filling up the open from which it has come; but whether there are lands or existing currents near the Pole to prevent its accumulating there, or whether that a warmer temperature exists to dissolve it, remains to be seen.

    Dr Kane wintered in Smith’s Straits, near the 79th parallel. From this point the following spring he sent parties over the ice northward about 125 miles in a direct line, when they came to an open sea, the shores of which they traced on the east nearly to 81 degrees 30 minutes, and on the western side to 82 degrees 30 minutes, approximately. At this far remote point, and from a height of 480 feet, which commanded a horizon of nearly forty miles, the ears of the party “were gladdened with the novel music of the dashing waves and a surf, breaking in among rocks at their feet which stayed further progress.’ As they travelled north the channel expanded into an iceless area, and taking 36 miles as the mean radium open to reliable survey, the sea had a justly estimated extent of more than 4,000 square miles.

    This was in the month of June, yet there was every indication that this water had been open during a most severe Arctic winter, for the shores did not have the “ice-belt” which elsewhere in Smith’s Strait indicates alike both permanent and annual freezing. Animal life, too, to which Dr Kane had been a stranger to the south, now burst upon the party. Geese and ducks were abundant, particularly the Brent goose, a migratory bird, which the Doctor had seen on his previous voyage in Wellington Channel, when they were flying toward the south. The rocks and the shore were crowded with sea-swallows, whose habits require open water, and which were then breeding; in fact, to use the Doctor’s words “it was a picture of life all around.” Of plants there is less said, as the season was too early for their development. This increase of animal and vegetable life, with the rise of the thermometer in the water, and the melted snow upon the rocks, were indicative of a milder climate towards the Pole.

    Another fact worth dwelling on is, that after a severe gale of several days from the north, there was no accumulation of floating ice, which is strong evidence that there was warmer water from whence the wind came, without ice, and that from an elevation of 580 feet, the open sea was “still without a limit, and moved by a heavy swell, free of ice.”

    In view of these highly interesting facts, the intrepid navigator does not venture to discuss the phenomena which give rise to them.

    ‘How far,’ says the Doctor, ‘this sea may extend — whether it exists simply as a feature of the immediate region, or as a part of the great and unexplored area communicating with the Polar basin — and what may be the argument in favour of one or the other hypothesis, or the explanations which reconciles it with established laws, may be questions for men skilled in scientific deductions. Coming as it did, a mysterious fluidity in the midst of vast plains of solid ice, it was well calculated to arouse the emotions of the highest order, and I do not believe there was a man among us who did not long for the means of embarking upon its bright and lonely waters’.

    We have little doubt the interesting facts made known by Dr Kane will lead to another Artic expedition. At some future day we may recur to the subject again, and venture to suggest some ideas toward a plan for reaching the mysterious Pole.

    The Perth Gazette and Independent Journal of Politics and News (WA) – Friday 10 April 1857

  74. barry says:

    This is an interesting admission:

    The melt extent algorithm used by Greenland Ice Sheet Today has been overestimating the melt extent, and as a result, daily images posted on this site in February and March may have indicated melt where none occurred.

    This makes you wonder what other kinds of issues remain undetected in the satellite data.

    Why use the word ‘admission’, like they’d been trying to hide something? It just sets people off (look at the comments).

    They do more than just ‘wonder’ about issues with data and methods. They investigate and amend when they discover problems. They checked their own work and corrected it, and then they publicised it. Sounds like the epitome of good science to me. NSIDC has always been up front about errors and data limitations.

    http://wattsupwiththat.com/2012/05/04/yet-another-error-in-nsidc-graphs/

    But I see the peanut gallery has found this story energising. NSIDC changed something, so they’re either fishy or their processes are too flawed to be useful. Eyeroll.

  75. D.B. Stealey says:

    Sure, barry. But they never seem to underestimate the ice melt, do they? Seems like they’re covering their butts here, before an inconvenient fact comes to light. Now that the P.R. damage is done, they come back and say, “Oops.”

    Alarmists like barry are nothing if not credulous. *eyeroll*

  76. Marcos says:

    Anthony,
    Didnt NSIDC say that they were going to change their sea ice anomaly period from 1979-2000 to something including more recent years? iirc, they said last year that the work was done and they were just waiting for the right time (whatever that means)

  77. jonny old boy says:

    In late spring of 2012 the very same organisation was telling a man in North East Canada ( who was looking out to sea as far as he could see from his living room window, staring at solid sea-ice with no liquid water anywhere to be seen ) that there was indeed no sea ice at all and he could merrily hop in his boat and sail away somewhere nice…..I actually menioned this on Mann’s facebooks site, and was summarily banned from the site….

  78. barry says:

    Sure, barry. But they never seem to underestimate the ice melt, do they?

    It doesn’t matter what they do, people will complain. If the Met Office say they had previously been underestimating temps, then the peanut gallery will call foul on the new, warmer record. (“Why are adjustments always up?!?”) If it had gone the other way, the peanut gallery would be saying what you’re saying about NSIDC. (“Why do they never seem to underestimate warming?!?”)

    There’s no consistency to these complaints – they’re contradictory. And predictable and boring. Any adjustment, any change of any sort is an opportunity to for people to grind their axes. Any change is an opportunity to suggest a conspiracy, malfeasance or whatever. That’s the only consistent part of it.

    [Formatting fixed -w.]

  79. Anthony Watts says:

    @Marcos, yes they did. I’ll look up that conversation.

  80. jayhd says:

    Numerobis, Barry and others – You seem to be missing the point of the criticism, at least my criticism. NSIDC and Greenland Ice Sheet Today are publishing, for public consumption mind you, maps and articles on the, for lack of a better way of putting it, the demise of the Greenland glaciers. These maps and articles are based on satellite images and computer models. Many of the maps and articles have a decidedly alarmist slant to them. These are then taken up by the CAGW/Climate Change advocates in the mainstream media and in academia. The big problem I have with all this is that all these maps and articles are based on data gathered by satellite and fed into computer models with little or no actual on the ground work to validate anything. For example, the correction highlighted in the article we are commenting on was for February and March of this year. But I ask the question, what about January? Or any of the earlier months? As Athony writes in his opening paragraph “This makes you wonder what other kinds of issues remain undetected in the satellite data”. Validating computer interpretations of satellite data is a very tricky affair, especially if the people doing the programming and validating have little or no real field experience. They tend to go on assumption, not observation. It is my opinion that too many of the people working in the “climate science” field overly rely on the accuracy of their computer models, to the detriment of real scientific field work.

    By the way, besides the problems with GISS I noted in an earlier post, I have also had real world experience while in the military with regards to the limitations of satellite imagery and its interpretation by intelligence “experts”. These experiences were, for the most part, somewhat unpleasant.

  81. barry says:

    It is my opinion that too many of the people working in the “climate science” field overly rely on the accuracy of their computer models, to the detriment of real scientific field work.

    How many field trips have been done over the last 3 years?

    I got 895 hits in google scholar googling ‘Greenland mass balance fieldwork’, setting the parameters 2011 to 2013.

    There will be a lot of double-ups, but on what information is your opinion based? Do you think there should be more funding for trips to the Greenland ice? What well-considered solutions do you have in mind?

  82. barry says:

    Aye, but you could imagine if there was a lot of money being spent on field trips to Greenland.

    “They have perfectly good satellites paid for by our tax dollars that can see the whole area. Excursions to look at ice in a few locations are a waste of money.”

    Peanuts, anyone?

  83. john robertson says:

    What climatologists engaging in exaggerations?
    Never happens, must be unprecedented since yesterday.
    The art of climatology is coming to resemble one of the oldest arts, more each day.
    Talespinning however is a respected and lucrative art.

  84. Gary Pearse says:

    With the extended very cold winter into spring in both Eurasia (they had to scrape off a Northern Ireland soccer field for a FIFA match two days ago) and North America, temps still -25C over much of the Greenland Sheet in the first few days of spring and a rapidly rebounded arctic ice sheet – still presssing against the north shore of Hokkaido, Japan- water may be scarce on the Greenland ice this summer.

    Also, having had a satellite-era record high Antarctic ice sheet extent in the SH winter followed by a rebound in one month to a positive anomaly of almost 1 million square km, look to cold weather this coming SH winter in South America, Australia, New Zealand and South Africa. I predicted last fall a particularly cold NH winter partly because of the record ice in Antarctica in SH winter (and partly because of subdued non-development of El Nino and the likely bending of the global flat trend to a decline). Commonly an especially cold winter in the SH presages one to follow in the NH (and vice versa until this zig-zag swing dampens down). Looking at the rapid ice growth in Antarctica at present, sets the stage for a new record Antarctic ice extent, a cold winter in SH, followed by another very cold NH winter. Any bets? Eww, it must be tough to be a burning-in-hell CO2 warming maven these days.

  85. tomwys says:

    Good analysis, Gary. Add early albedo effects in northern (and later, all of) Asia resulting from open Arctic waters, and your picture, with record SCE, is relatively complete!

  86. Gary Pearse says:

    barry says:
    March 23, 2013 at 5:09 am

    One of the problems is that if you are an analyst who has a strong belief in the catastrophic degree of global warming, your analysis is going to go as far to the extreme as is decently possible – the data gives you a range to choose from. I pointed out about 4 or 5 years ago to theweathernetwork.com that I had made better forecasts than they for a period of 3 months by using their forecasts and trimming the heat off by about a degree. I emailed this to them.and got no reply. Today, I note thru late winter and this cold spring, their 2 week forecasts trend always starts below normal where it is at, but manages in the final week to climb up to above normal. Why? Because, gee, it must balance out, mustn’t it in these times of CAGW. I think a study of the meteorological data of HadCrut, GISS, etc. by totally independent specialists would have given cooler temperature forecasts these past 15 years or so. It would be a good exercise to give data without identifying the period it came from and have them make a forecast to compare with the real one – maybe someone should try this – Bastardi maybe? You may also have noticed barry that they have added things on to the sea level data to make for more sea level rise, etc.

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