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Alice Springs–A Closer Look At The Temperature Record

March 26, 2012

By Paul Homewood

 

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                               Before                                                                                 After

As promised, I have a had a good delve into the Australian Bureau of Meteorology’s records concerning Alice Springs, where GHCN have completely corrupted the temperature history by cooling the past.

 

First, a look at the size and timing of the adjustments.

 

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Between 1940 and 1974, the adjustment has reduced the original temperature record by about 2 degrees centigrade. In 1975, the adjustment halved to about 1 degree and remained around this level till 2009. In 2010, the adjustment disappears.

OK, it may be possible that the original readings were in error, or that there have been changes to the station location or methods of observation which might have caused the temperature record to be unreliable. So what does the BOM’s database tell us? A quick check shows that their records tally with the original GHCN V2.0 dataset, in use till last year, as these two graphs for Max and Min temperatures illustrate.

 

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Temperatures are pretty much the same now as they were 70 years ago. The Bureau’s records, however tell us a lot more. The metadata for Alice Springs is shown in considerable detail and confirms the following :-

  • The station has been at the same site since 1941. (Elsewhere the BOM describe how they will give a station a new reference number if it has moved more than 2 km.)
  • There has been no change in hours of observation since 1941. All temperatures are recorded every three hours and daily temperatures logged at 9.00 am, a practice used throughout its 71 year history.
  • There have been no significant changes in equipment, and certainly none at all around 1974 or 2010 when the step changes occurred in adjustments.

The GHCN Technical Log makes it crystal clear. Homogenisation Adjustments are designed to “remove the impact of non-climatic changes “ such as relocations, changes in instrumentation and observational practices. There have been no such changes, so there should be no adjustment.

 

One further observation.The weather station at Alice Springs is located at this airport, yet GISS make absolutely no allowance at all for UHI effect. Does anyone honestly believe that the development of a modern airport like this has not had an effect on temperatures, when compared to the grass strip that would have been there 70 years ago?

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9 Comments
  1. Coldish permalink
    March 26, 2012 1:44 pm

    What do you make of Willis Eschenbach’s articles on the Darwin T record?
    The Smoking Gun At Darwin Zero :: Examination of the Darwin, Australia temperature record.
    http://wattsupwiththat.com/2009/12/08/the-smoking-gun-at-darwin-zero
    Darwin Zero Before and After :: Examination of the Darwin, Australia temperature record, part II.
    http://wattsupwiththat.com/2009/12/20/darwin-zero-before-and-after

    • March 26, 2012 5:09 pm

      It is interesting that Willis says “Until someone can point out that mystery method, however, I maintain that the Darwin Zero record was adjusted manually, and that it is not a coincidence that it shows (highly improbable) warming.

      I had assumed the GHCN database was just too big and complex for any manual intervention, but I might have been wrong!

      It is also interesting that Willis posed these questions to GHCN and presumably never got any answer. I have been waiting 10 weeks now and just get fobbed off each time I chase.

  2. Paul Matthews permalink
    March 27, 2012 1:31 pm

    The fabricated warming at Alice Springs can be seen in the graphs produced by GHCN, see
    ftp://ftp.ncdc.noaa.gov/pub/data/ghcn/v3/products/stnplots/5/50194326000.gif

    The graph top right shows the original data with virtually no trend.
    The middle right one shows the ‘adjusted’ version with almost two degrees of warming added.
    The bottom right red and blue graph shows the adjustments – this is basically the same as your graph but a bit smoother.

    Having downloaded the data file from the GHCN site and looked at the numbers, it shows that one big past-cooling adjustment of 1.13 degrees kicks in at September 2009. The adjustment then jumps up to 2.7 degrees in 1973 and then it’s 2.12 degrees before about 1970.

    It looks like the GHCN algorithm is deciding that the cooling in the raw data in 1973-4 and 2009-10 must be wrong and somehow adjusting to get rid of that. But we don’t know exactly how it works because GHCN won’t release their code. In their recent paper (Lawrimore et al 2011) there is a mention of looking for ‘climatological outliers’ (monthly numbers off by more than 5 standard deviations) but no mention of a check for sharp drops in temperature.

  3. Paul Matthews permalink
    March 27, 2012 5:30 pm

    As Paul H mentioned in his previous post, An adjustment like Alice, this big warming adjustment applied to Alice Springs has only appeared in the last few weeks.

    In the version of the GHCN data file from Jan 23, the picture was completely different. There was no adjustment back to 1991. Then in the period 1974-1990 the past was warmed by the adjustment by 0.66 degrees. Before about 1970 the adjustment was a cooling of 0.33 degrees.

    So some time between Jan 23 and March, the Alice Springs past-cooling was changed from 0.33 to 2.12. This was probably the introduction of their new version GHCNM v3.1.1 that their changelog file says was introduced on Feb 7th. However, the plots on their website, for example the one in my previous comment, still say v3.1.0.

  4. Brian H permalink
    March 28, 2012 12:38 am

    When you’re reliant on the integrity of the fudgers to properly document their fudging, you’re pretty much fugged.

  5. March 28, 2012 2:34 am

    The Alice Springs Airport station (No. 015590) has operated since 1941. The earlier station (No. 015540), located at the Telegraph Station just north of Alice Springs town, operated from 1878 to 1953. The distance between these two locations is about 12km. Presumably some adjustment was necessary when the two sets of data were amalgamated and this would have been easy to compute as there were about 12 years of overlapping record. Nevertheless, the combined record should not be marketed as though it was a single record at the airport.

    The reasons for the GHCN sudden adjustments of 0.5 degrees in 1975 and 2009 appear to be quite subjective and highly suspect. What was the adjustment (if any) made prior to 1941? Maybe 1975 was about the time when jet aircraft commenced using Alice Springs Airport! But what happened suddenly in 2009?

  6. March 28, 2012 9:37 am

    Whoops, my mistake! Even in the Southern Hemisphere jet exhaust should result in an increase in local temperatures and not the other way around! These sudden GHCN adjustments are completely illogical to me but lets keep trying to get to the bottom of this question.

  7. April 7, 2012 8:04 pm

    Interesting to see that the skulduggery isn’t limited to the Arctic. I just posted a link to this page on the Real Climate site.

    I wonder if they’ll allow my comment to stand.

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