Some CRU Anomalies

The previous post showed that changes to weather station data between CRUTEM3 and CRUTEM4.6 are responsible for converting the Hiatus into a warming trend. Here I look into some examples of those changes. I first looked for big changes in the monthly ‘normal’ values between 1961 and 1990. This identified some inconsistencies.

WMO identifiers are supposed to be fixed locations but Station 218240 has been changed and moved thousands of miles between CRUTEM3 and CRUTEM4.6. Despite this several temperature measurements remain exactly the same, which is simply impossible!

Same ID but different stations both using exactly the same 3 year temperature record ?

At the other extreme we have stations whose values have changed significantly

Same station but very different monthly temperature and different normals.

136 stations have seasonal monthly normals that have changed by more than 1C between CRUTEM3 and CRUTEM4.6. In some cases eg. Los Angeles, the station has moved in altitude going from downtown to Pasadena. However, others like Miami apparently are the same station but record completely different monthly mean temperatures going from CRUTEM3 to CRUTEM4.

Miami monthly temperatures CUTEM3 compared to CRUTEM4.6

Maybe this is a different station in another location since Miami is flat. However if so then this just demonstrates how great the variability is, even within one city.

What I think this really highlights is the lack of (available) metadata describing CRU station changes and updates, plus at least one data quality control issue. This doesn’t  explain why the post 1998 warming trend changed.

 

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12 Responses to Some CRU Anomalies

  1. Nick Stokes says:

    Clive,
    I have done some analysis of the Had3 2011 data compared with Had4.6. What is clear is that Had 3 had gross errors that were corrected in later versions, and I think you are finding some of those. Maybe the correction did help to change some trends.

    There are 4791 stations that are common to both, and I looked at these over the years 1991 to 2010. There were a total of 397076 station-months of shared readings – ie reported in both. Of these 317654 (80%) were completely unchanged. Another 7.5% were within 0.2C. That leaves about 12.5% with larger changes. Clearly there is no mass adjustment.

    I haven’t got far yet with characterising that 7%, but I noted first the max difference, which was 70C. That was for an arctic station Isachsen, which reported a September value of -78.9C in Had3. Had4.6 put this at -8.9, which is much more reasonable. Typo. The next largest was at Thule, N Greenland in April 1995, which Had3 said 23.3C. Had4.6 corrected this to -23.3C.

    Summary – I think where the data overlapped, there was generally no change. Some data did vary throughout; I suspect that will often be a change of supplier. And some data had gross errors, so far seeming to be in Had 3.

    • Clive Best says:

      Thanks Nick,

      It looks like some of these old files were written by hand. What is still not clear to me at least is how they were generated. I remember when that when I looked at this years ago that some 100 stations simply changed IDs. The list is here

      I expect that you are right and many errors were corrected with CRUTEM4. However, it was not just HadCRUT which sowed the pause. I think GISS and NCDC showed it in 2012 as well.

      You know I think best the way to form the global average is to treat the earth as a sphere, which also increases recent trends. However I think one possible bias is the lack of coverage in earlier years. This applies to all methods.

  2. Clive, I totally admire your tenacity in digging into the vagaries these crooks have wormed into the ‘data’.
    I depend completely on the IR spectrum analysis that you applied to the Harvard-HiTran published output. That 4.7 w/m2 , max/ greenhouse, remains an ICON in the field. It is probably the best and only good figure in the entire earth temperature debate. Ironic isn’t it that the CO2 greenhouse warming question is the only good ‘known’ in the entire hoax.

    Keep up your great work!

    arationofreason

  3. Lou Maytrees says:

    It also does not explain why you continue to use one extreme high temperature anomaly, the 1998 El Nino, as a starting point for a ‘pause/hiatus’?

    And it does not explain why you never mention all the surface low temperature anomalies over that same time frame which rose +.3*C, also nullifying your ‘gap in the sequence’.

    • He doesn’t do what you say he does. You need to read the articles properly

      • Lou Maytrees says:

        David – in Clive’s previous post he opened with ‘”… IPCC assessment in 2013 showed a clear pause in global warming lasting 16 years from 1998 – 2012.”

        Numerous IPCC scientists debunked the 1998 claim after the 2013 report as an extreme high anomaly caused by the El Nino that year and that it had little to do with any kind of pause.

        So that is Clive’s ‘opinion’, that 1998 ‘clearly showed’ the start of a pause, not the IPCC’s.

        Plus he also started this post with “The previous post showed changes …” and he went on to question temps in a couple of stations like he did of the 4000+ in the earlier post. He then ended this post with “This doesn’t explain why the post 1998 warming trend has changed.”

        So this post surely seems an extension of the last and that is why I asked why a clear outlier and an extreme high anomaly caused by the 1998 El Nino is considered by some, certainly not the IPCC, to be the start of a ‘pause/hiatus’.

    • Clive Best says:

      Actually it was the IPCC who used 1998as the start of the hiatus.

      • Lou Maytrees says:

        Right, it’s all the IPCCs’ fault.

        Not Benny Peisers’, or Moncktons’, or the FoxFakeNewsChannels’ or all the other right wing media pundits who started the whole brouhaha in the first place.

        To my limited knowledge the IPCC has never used 1998 as the start of any kind of pause tho they did try to answer why some people wrongly think that it was the start.

        • Clive Best says:

          You’re simply wrong.

          See Box 9.2 Chapter 6.

          • Nick Stokes says:

            “See Box 9.2 Chapter 6.”
            Well, Chapter 9. But I think that box puts the question of “whatever happened to the hiatus?” into perspective. The Box said:

            “Depending on the observational data set, the GMST trend over 1998–2012 is estimated to be around one-third to one-half of the trend over 1951–2012 (Section 2.4.3, Table 2.7; Box 9.2 Figure 1a, c). For example, in HadCRUT4 the trend is 0.04ºC per decade over 1998–2012, compared to 0.11ºC per decade over 1951–2012.”
            Had4 is now 0.0522C/decade. NOAA is 0.077; GISS is 0.10C/decade. So the movement in Had4 has been just a small part of the difference between it and other indices.

            I must say that on reviewing HADCRUT in detail, I think IPCC should stop using it as a reference. I think the other indices are better. They have better quality data, and use better integration methods. Hadcrut is primitive.

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