GISTEMP -vs- HadCRUT

By Steven Goddard

As discussed in my last post, GISS claims to have better Arctic coverage than Had-Crut, and uses that as an explanation of why they are trending upwards when Had Crut isn’t.

“A likely explanation for discrepancy in identification of the warmest year is the fact that the HadCRUT analysis excludes much of the Arctic ….. (whereas GISS) estimates temperature anomalies throughout most of the Arctic.”

In this post, I will show a number of things wrong with that claim. GISS uses the maps below as evidence of their better coverage.

The problem is though, that GISS actually has very little Arctic data. The “GISS 2005” map above uses 1200 km smoothing (which assumes that the weather in London somehow affects the weather in Monaco.) If we look at the un-smoothed GISS data from 2005 (below) we see something very different.

GISS actually has very few temperature readings in the Arctic. much less than Had-Crut. The map below shows the differences in coverage. Areas where Had Crut has better coverage are shown in green. Areas where GISS has better coverage are shown in red. Note that Had-Crut has more extensive coverage than GISS on almost every continent.

Now, let’s look at some of the specific problems with the GISS smoothing in the blink map below, which alternates between Had-Crut and GISS 2005 data.

  1. GISS completely missed a cold area north of Svalbard. They show that region several degrees above normal.
  2. GISS has almost no coverage in the Canadian Arctic
  3. GISS has almost no coverage in Greenland
  4. GISS has no coverage in the Chukchi Sea or Arctic Basin
  5. GISS has very poor coverage around Antarctica
  6. GISS has very poor coverage in Africa
  7. GISS missed large regions of below normal temperatures in the southern oceans and Antarctica

Now, let’s compare GISS Arctic coverage with UAH, below. Note that UAH has much better coverage at both poles than GISS (as well as everywhere else.)

[Image]

Conclusion: GISS implications that that they have better Arctic coverage than other sources are simply untrue. They have very little actual data near either pole, and their extrapolations in those regions are demonstrably poor.

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63 thoughts on “GISTEMP -vs- HadCRUT

  1. So can we paraphrase:
    “the HadCRUT analysis excludes much of the Arctic ….. (whereas GISS) estimates temperature anomalies throughout most of the Arctic.”
    as:
    Hadcrut reports what has been measured while GISS guesses at the missing bits.

  2. I wrote on my website as a 1st April joke this year that all official weather stations in the country had been shut down and observations were replaced by computer models, which will greatly improve coverage and data quality. The only thing that will limit observations is computer power.

    While it was an obvious joke, this is the general direction that we’re heading in.

  3. Just a few months ago, a Russian think tank complained about mis-measurement by the CRU in Siberia and GISTemp is even worse? Wow.

    http://climateaudit.org/2009/12/16/iearussia-hadley-center-probably-tampered-with-russian-climate-data/

    This winter was perhaps the coldest Siberia has ever experienced in the modern era, but a GISTemp winter anamoly map shows a hotspot there.

    http://www.dailymail.co.uk/news/worldnews/article-1260132/Russian-weatherman-strikes-blow-climate-change-lobby-announcing-winter-Siberia-coldest-record.html

    http://data.giss.nasa.gov/gistemp/maps/

    Then a glance at the same map shows the Arctic was relatively balmy. Well, someone’s balmy.

  4. Of course the AGW croud will show that it doesn’t make any difference to the Global Temperature though, just like all the other “Dropped” stations.

  5. Hansen makes some pretty bold assumptions in that paper concerning Arctic atmospheric behavior having a direct correlation to “global warming”. Apparently in his view Igor Polyakov’s research, arguably one of the foremost experts on the Arctic, is completely irrelevant as no citations are referenced.
    http://soa.arcus.org/sites/soa.arcus.org/files/sessions/2-1-observations-arctic-change/pdf/2-1-4-polykov-igor.pdf
    http://www.iarc.uaf.edu/people/indiv/iarc_all_staff.php?photo=ipolyakov

    Note as well the incorrect claim for stratospheric cooling due to CO2 increases. There is no evidence for that in the observational data; quite the opposite in fact has been the case.

    Hansen’s paper is loaded with errors and untested assumptions, which no doubt others will expose.

  6. How much error is introduced by smearing the temperature of a few arctic stations across vast stretches of unmeasured area and then weighting the grid cells equally? Can you calculate the differences between smoothed and unsmoothed grid cells for all cells that have real data and arrive at a meaningful number for the uncertainty introduced by smoothing?

  7. Very succinct and understandable presentation, Steven Goddard. A few well-chosen pictures are worth a thousand words, as they say.

    On another topic, one for Anthony, I note that now my name and email address are being primed in the reply box, which is a welcome return to how things used to be. Also, either you have tweaked the layout and it now looks better than when you first introduced the new scheme, or for some reason I have become more used to it. In either case, I am feeling more positive about it than formerly and thought I’d let you know, as I previously expressed negativity.

  8. A C Osborn

    I think Hansen’s presentation is explaining how their methodology does make a difference to the global temperature record. I’m surprised that they would be bragging about it though.

  9. Michael Larkin says:
    May 18, 2010 at 7:22 am

    “On another topic, one for Anthony, I note that now my name and email address are being primed in the reply box, which is a welcome return to how things used to be. ”

    Michael, you didnt by any chance swith from IE to Firefox? The default security settings in IE are set so these things doesnt pop up. On Firefox they are set to pop up.

    The sad thing about IE, is that all default settings are set in such a way, that people quickly move to Firefox, instead of trying to sort out the security settings in IE.
    I have done so myself. Nothing irritates me more, than having to enter my username again and again.
    Of course this isnt as secure as not letting it pop up, but I’m not exactly working for the CIA either.

  10. A C Osborn says:
    May 18, 2010 at 6:06 am
    Of course the AGW croud will show that it doesn’t make any difference to the Global Temperature though, just like all the other “Dropped” stations.

    For The Denver Post the story is still global warming. Since these are a AP stories, I’m sure they are being carried in other cities. The data is gleaned from NOAA. Both articles acknowledge recent cooling in the northern hemisphere

    Cooler-than-normal places included Mongolia, Argentina, far eastern Russia, the western contiguous United States and most of China.

    I’ll take it as progress that MSM at least makes the concession prior to dismissing it as just “weather”. Readers may be a bit more demanding that they used to be.

    El Nino is blamed for the temps, and “record thinning” of ice in the North.

    And the heat goes on: warmest March on record
    By RANDOLPH E. SCHMID AP Science Writer

    Warmest April on record, climate agency reports
    The Associated Press
    Posted: 05/17/2010 02:03:44 PM MDT
    Updated: 05/17/2010 02:03:44 PM MDT

    The links are very slow, so I won’t post them here.

  11. Now, let’s compare GISS Arctic coverage with UAH, below. Note that UAH has much better coverage at both poles than GISS (as well as everywhere else.)

    UAH has no coverage at either pole, so I’m not sure what you’re referring to?

  12. Steve Goddard: You wrote, “As discussed in my last post, GISS claims to have better Arctic coverage than Had-Crut…”

    It is a justified claim. The GISS Arctic coverage is significantly better than the Hadley Centre’s. Has been for years. Here’s a North polar stereographic map (65N-90N) showing the March 2010 CRUTEM3 readings:

    And here’s the same map showing the GISS land surface readings for March 2010, with 250km smoothing:

  13. Interesting that HadCRUT & GISS seem to avoid any confrontation on who is best, no counter cliams seem to be made. I wonder why? Or perhaps I am too cynical!

  14. Gary says:
    May 18, 2010 at 6:50 am

    “How much error is introduced by smearing the temperature of a few arctic stations across vast stretches of unmeasured area and then weighting the grid cells equally?…”
    ___________________________________________________________________________
    A. J. Strata looked into the error. he wrote up his finding here:

    Alarmists Hide Truth About (Lack Of) Global Warming:
    “…I am going to focus this post on two key documents that became public with the recent whistle blowing at CRU. The first document concerns the accuracy of the land based temperature measurements….

    The second document contains 155 graphs showing the raw global temperature measurements and ‘trends’ for every country from 1900 though today. It contains two version of the CRU ‘processing’ – one from 2005 and one from 2008. What is just amazing from this ‘raw’ data is the realization that many areas of the Earth are not showing a huge upswing in temperature. The raw data paints a completely different picture than the final ‘results’…”
    http://strata-sphere.com/blog/index.php/archives/11420

    here are other posts by Strata that may be of interest
    Proof Why Global Warming Alarmists Are Mathematically Wrong:
    http://strata-sphere.com/blog/index.php/archives/12246

    Statistical Tricks 101 – How To Create Runaway Global Warming:
    http://strata-sphere.com/blog/index.php/archives/11919

    BBC Confirms AJStrata’s Take Shoddy CRU Code:
    http://strata-sphere.com/blog/index.php/archives/11747

    CRU Code & Data A Disaster:
    http://strata-sphere.com/blog/index.php/archives/11556

  15. GISS statements of “warmest ever” are a skeptical concensus tool without equal.
    10’s of millions of people are reading these statements while putting up with what seems to be a winter that won’t go away, and, on top of that, a totally blown winter forecast.
    Makes it’s own gravy.
    People know they are being fed a line.
    The MSM is so disconnected as to not notice how bad the stuff they report is.

  16. stevengoddard says:
    May 18, 2010 at 9:25 am
    Phil,

    The maps showing UAH coverage near the poles are posted in the article.

    Unfortunately those lousy maps don’t show latitude so there’s no way of knowing how close to the pole they go (in any case you said coverage at the poles not near the poles). As I recall UAH cover up to 82.5N so that’s no coverage within ~450 nautical miles of the pole.

  17. Steve Goddard, You replied, “Looks to me like Had-Crut has much better coverage than GISS in the Arctic,” and presented the following links of Global Maps, some with sea surface temperatures. I on the other hand presented you with a maps showing the areas of the ARCTIC with actual land surface station readings that are on record as having been used by GISS and Hadley Centre for that month.

    Your link…
    http://docs.google.com/View?id=ddw82wws_631f2d3svc8
    ..shows station locations. Obviously they do not all report.

    Your link…

    ..also shows stations loactions but do not indicate which report.

    Your link…

    …shows primarily SST readings in the Arctic. Again, my comparison was for land surface readings–that is, actual station readings.

    Your link…
    http://climateinsiders.files.wordpress.com/2010/05/giss_area_vs_had_crut.jpg?w=497&h=568&h=568
    …represents averages for the year 2005. The stations used by the Hadley Centre do not remain constant over the course of a year. Some are used one month, others the next. By illustrating the annual average, they capture all of the stations employed that year, even though they may not have appeared at the same time. Also, the appearance of better coverage is again skewed by SST anomalies and the bleed-over of SST data onto land, which is another problem with the Hadley Centre’s data.

  18. kwik says:
    May 18, 2010 at 8:24 am

    “Michael, you didnt by any chance swith from IE to Firefox?”

    No, kwik. I’ve been using Firefox for years. Only today, with no changes of version or setting, did the primed reply box appear.

  19. Here you can compare them all:

    http://www.junkscience.com/MSU_Temps/Warming_Look.html

    page 27 of this report give the temperatures from 1796 to 2009 for Armagh Ireland (the northern Hemispehere):
    http://star.arm.ac.uk/annrep/annrep2009/annrep2009.pdf

    Compare the temps with the temps given by DMI for the arctic and you can see the trends fit well: http://ocean.dmi.dk/arctic/meant80n.uk.php

    In Armagh 2006 and 2007 have been the warmest years and there has been no warming from 1995. Interesting are the trends in warming in the beginning of the nineteenth century and in the years 1920 -1950 with the temps in 1945 and 1949 being in the range of those from 2006 and 2007.

  20. Ibrahim

    You made a bunch of statements, and then post links which don’t seem to have much information supporting your statement. For instance, the DMI graph doesn’t show trends. In fact non of your links show trends.

  21. Well, well, well. The satellite measurements (UAH) and GISS seem to be in close agreement. Certainly ENSO is part of this, but the baseline is steadily rising.

  22. Have you ever watched shows where hikers ignored seemingly small pieces of information and ended up in trouble?

    2010 is the fifth warmest year in HadCru to date, the warmest in GISS, the warmest in satellite records…

    A storm cloud gathers at the head of the valley. It looks a long way off. Do you continue up the mountain?

  23. GISTemp warming menses from the active imagination of James Hansen.

  24. Ammonite

    I’m terrified about that 0.65 degrees warming over the last 130 years. If it keeps up like that, Colorado may have a decent climate in about 500 years. Why can’t it warm up faster???

  25. If you place a glass of ice water on a warming plate and turn on the heat, heat will flow into the glass and drive a phase change, consuming all of the heat. The temperature you measure in the glass will show no change, no warming, until all the ice has melted. Then it will rise steadily (ultimately producing a second phase change).
    A portion of the current thermal imbalance is going into melting land ice, and both the satellite-based GRACE mission and the land-based GPS measurements of post-glacial rebound show an acceleration of the melting of Greenland land ice. GRACE also shows an acceleration of the melting of Antarctic land ice.
    When the ice quits melting, I’ll believe that CO2 is not driving climate change.

  26. Clarifying Owen’s point, the energy being absorbed by the oceans is a couple of orders of magnitude higher than that melting ice.

  27. Steve Goddard and Bob Tisdale: Why don’t you guys do a “Surface Stations” type approach and figure out who is measuring what in Arctic/Antarctic areas. And either reply coherently and definitively to this troll named Phil. or ignore him.

  28. The ranger warns of possible inclement weather. Steven has lived near the mountain his whole life. He laughs into the breeze and sets forth.

  29. Given that understanding the Arctic region weather conditions may be so important, I am surprised that the National Oceanic and Atmospheric Administration’s National Data Buoy program has not been extended to include a set of buoys that are specially designed to populate the Arctic Ocean. I expect this would be a real design challenge, but I do think it could be done.

    Below is a link to NOAA’s NDBC (National Data Buoy Center) site where you can use a map to select any of their Weather Buoys in the world and get a list of recent observations.

    http://www.ndbc.noaa.gov/

  30. Owen:

    A portion of the current thermal imbalance is going into melting land ice, and both the satellite-based GRACE mission and the land-based GPS measurements of post-glacial rebound show an acceleration of the melting of Greenland land ice. GRACE also shows an acceleration of the melting of Antarctic land ice.
    When the ice quits melting, I’ll believe that CO2 is not driving climate change.

    My understanding, from what I’ve read here, is that ice loss in the Antarctic is the result of increased glacial outflow, which is due to increased snowfall on the surface, and also to the breaking off of shelf ice that had blocked outflows, not to the melting of surface ice. It’s always below freezing in Antarctica, except maybe briefly in the Peninsula.

    In Greenland ice loss is also mostly due to increased glacial outflow from increased snow. There is also increased melting around the edges of ice shelves when there is a warmer than normal current passing by locally, which happens occasionally due to natural variation.

  31. My point is that (for those who are not totally committed to the it-ain’t-ghg’s bandwagon) it is worth pausing to consider the net ice loss in the Arctic, Antarctic and world’s mountain ranges, the rising ocean heat content and the persistent occurence year-on-year of global temperatures in the top 10 ever measured. The prudent course is to treat this information with respect and carefully consider its implications. Perhaps people who study climate for their living and design successful interplanetary spaceships (eg. Venus Express) may be worth listening to!?

  32. Jim F wrote: You asked Steve Goddard and me, “Why don’t you guys do a ‘Surface Stations’ type approach and figure out who is measuring what in Arctic/Antarctic areas. And either reply coherently and definitively to this troll named Phil. or ignore him.”

    Let’s look at what Phil wrote: “As I recall UAH cover up to 82.5N so that’s no coverage within ~450 nautical miles of the pole.”

    And as far as I know, Jim F, the coverage Phil listed is correct. The satellite coverage only reaches so far, so UAH infills north of 82.5N and south of 70S. This is similar to what GISS does. GISS also infills where there is no data. The Hadley Centre, on the other hand, leaves the areas without coverage blank. If an area is left blank, it is easily recognized as being an incomplete measure of “Global” temperature. But GISS and UAH aren’t presenting a true “Global” product either. In my eyes, the problem with the infilling used by GISS and UAH is that it gives the impression of complete coverage, when it’s far from being complete.

  33. stevengoddard says:
    May 19, 2010 at 6:13 am
    Bob,

    I don’t see any reason to believe that either UAH or RSS “infills” data. Their coverage near the poles is much greater than GISS.

    As I said before they don’t have data closer than 82.5ºN and S and in the case of the South Pole RSS don’t produce data beyond 70ºS for TLT because of interference from the ice.

  34. A few months ago, over at treesfortheforest , Chad did a comparison of GISS and HadCRUT trends using common spatial coverage. I think he found that about half of the trend difference in recent years could be explained by differences in areal coverage, leaving the rest to procedural differences…at least that was my interpretation of Chad’s results.

    -Chip

  35. stevengoddard says:
    May 19, 2010 at 12:01 pm
    Phil.

    82.5 degrees is what the RSS and UAH maps show. I don’t see any evidence of infilling.

    There certainly isn’t on RSS since their cut off line is very clearly shown. It’s not so clear with UAH since their maps are rubbish and don’t show lat/long, the implication of their maps is that there is infilling since the contours run to the top and bottom edges of the map which are by implication 90ºN/S. Even indicating the projection used would be a help or using a unambiguous one like RSS do.

  36. stevengoddard says:
    May 18, 2010 at 12:06 pm
    Bob,

    I hear you, but it still looks to me like Had Crut has better coverage.
    http://docs.google.com/View?id=ddw82wws_635ftj7fzgc

    GISS doesn’t have any “coverage” of its own, it uses existing temperature records which it then processes to give a best estimate of the global temperature anomaly for each month and year. Since it’s main business is climate models which definitely do make predictions for the Arctic and Antarctic, places which are hard to measure (even with satellites – the well known “pole holes”), they use best-guess techniques for estimating temperature anomalies. Not temperatures.

    HadCrut can simply say – “we don’t measure that area”. Indeed. Look at their monthly data in text format:
    http://www.cru.uea.ac.uk/cru/data/temperature/hadcrut3vgl.txt
    See the second line of every year ? For example, 1998:
    1998 0.486 0.739 0.520 0.608 0.570 0.579 0.651 0.616 0.400 0.409 0.342 0.424 0.529
    1998 81 82 81 79 80 78 79 79 78 79 79 80

    Their data format is:
    Hemispheric/global average data file format
    for year = 1850 to endyear
    format(i5,13f7.3) year, 12 * monthly values, annual value
    format(i5,12i7) year, 12 * percentage coverage of hemisphere or globe
    Coverage of 0 means data not yet available

    Hence, every month shows the percentage coverage of hemisphere or globe. The Jan temp. anomaly was 0.486° C, and this was for 81% of the globe. Apr had a temp. anomaly of 0.608° C over 79% of the globe, etc.

    When HadCrut says 1998 is the warmest year, with a temperature anomaly of 0.529° C, they mean for less than 80% of the surface of the Earth (79.5833% average coverage that year). Since the Earth has a surface of 196,940,400 square miles, that means HadCrut just ignores 40,208,730 square miles. No “best estimate” – just give this 20% of the Earth’s surface the global average for that month, or that year.
    That’s what they are doing when they say 1998 had a global temperature anomaly of 0.529° C (relative to the 1961-1990 climatology). They are infilling the masked area with the global average for that year – which, these days, is too low for the Arctic.

    http://www.columbia.edu/~jeh1/mailings/2010/20100115_Temperature2009.pdf
    Look at Figure 3 in this Hansen paper – the only reason GISS “best-guesstimates” gridboxes that have no data by using nearby gridbox data is because that’s a better guess for temperature anomaly than global average anomaly – which is what HadCrut does, when giving global temperature anomaly results.

    GISS needs a best estimate of entire, global temperature anomalies each year – HadCrut just ignores 1/5 of the planet, and “estimates” that the temperature anomaly there is the same as the average for the entire planet.

  37. JohnH says:
    May 18, 2010 at 11:12 am
    That would explain the back to average ice extent then ?

    Yes, due to rapid global warming, the Arctic sea ice is back to the 2007 average:

    And poised to drop below.

  38. Hi Anthony,
    Could you add the error bars, to see if they match ?

    I mean as both data sets are global average temperature, they should match if uncertainties were appropriately calculated.

  39. stevengoddard says:
    May 19, 2010 at 11:21 pm
    Phil,

    What part of “uah” is it that you are not seeing in this url?

    http://discover.itsc.uah.edu/amsutemps/AAT_Browse.php?chan=1&satnum=15&aord=a

    So they have linked to the NASA Marshall Flight Center map (What part of the “NASA-MSFC” logo is it that you are not seeing?) The UAH map which you also linked to looks like this:

    Note the URL and © statement, this is their post processed data which allows for drift etc. and appears to infill the polar regions (within the limits imposed by the previously described poor mapping). Had UAH presented their data as professionally as NASA-MSFC and RSS there would be no problem, but they don’t.

  40. stevengoddard says:
    May 19, 2010 at 11:22 pm
    Anu,

    I would describe it as a “worst estimate.”

    Faulty estimates of Arctic warming lead to faulty estimates of Arctic sea ice melting.

  41. Does anybody know how north pole and south pole are defined for the UAH temperature departure list?: http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt. North pole had a new record in april 2010. South pole with no data south of 70 °S and north pole without data north of 82.5 °N … so maybe Chicago belongs to north pole???

    Nevertheless the UAH list is much better than the CRU list without any descriptions:
    http://www.cru.uea.ac.uk/cru/data/temperature/crutem3gl.txt

  42. Climate Kate says:
    May 20, 2010 at 10:34 am
    Does anybody know how north pole and south pole are defined for the UAH temperature departure list?: http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt. North pole had a new record in april 2010. South pole with no data south of 70 °S and north pole without data north of 82.5 °N … so maybe Chicago belongs to north pole???

    But as you will have noticed Steve is determined not to acknowledge that.

    Nevertheless the UAH list is much better than the CRU list without any descriptions:
    http://www.cru.uea.ac.uk/cru/data/temperature/crutem3gl.txt

    Although on their index page they do give you a key, more clearly than the titles on UAH (Npol doesn’t tell you that it’s 60ºN-82.5ºN for instance).

    “Hemispheric/global average data file format
    for year = 1850 to endyear
    format(i5,13f7.3) year, 12 * monthly values, annual value
    format(i5,12i7) year, 12 * percentage coverage of hemisphere or globe “

  43. This kind of bickering and pissing match is strictly unproductive. What is the argument or the issue? Why don’t you “define the problem” and then address it? I am a scientist, but I’ll be damned if I’m going to dig into the data to see what this post finally devolves to. I suspect a whole bunch of non-scientists turned this one off a long time ago. That’s beginning to be an issue here – several people putting up data without any clear explanation of what it supposedly means, then the discussion degenerating into multiple posts of one link after another with yet more date with no attempt to answer one another’s questions. That’s a sure prescription for failure.

  44. Does anyone else see the irony that GISS stands for “Goddard Institute for Space Studies”?
    Any relation, Steve?

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