Category Archives: ACORN SAT

BoM latest Rolls Royce adjusted temperature series

Australian March days were hotter in 1938, 1951, 1980, 1986, 1998 and 2005

The ABC acts as the BoM faithfull media lapdog – March temperatures sets record as hottest ever, Bureau of Meteorology says – We can see the duplicity in the way the article fails to be explicit about mentioning daytime temperature but in fact where they say “…reaching 1.7 degrees Celsius above the long-term average.” That is the MEAN they are talking about (max + min/2) and we all know the mean is little talked about. This beaten-up “Hottest March” did NOT have the hottest days, 1986 had way hotter days. Here are the anomaly charts first.
March max history 2016 no record despite ACORN tweaks
March mean history 2016 sneaky ACORN created record that BoM trumpets
March min history 2016 big record helped by ACORN tweaks – BoM silent on meteorological reasons for the min record
SE Australia 1940 March max hottest by a country mile despite ACORN tweaks
SE Australia 2016 March min record helped by ACORN tweaks
SE Australia 2016 March mean record helped by ACORN tweaks but a mystery how the narrow min record goes with the cooler max result to just give the mean a record by a nose
Now the anomaly maps – March max only a pussy of a hot month – 1986 March max – now there are hot days –
March min – oops there is the NNTHS
March mean
No hot March nights at Giles – our only purpose built professionally staffed met station in central Australia – shame about that.

Was March 1940 hotter than March 2016?

The BoM thinks our Indian summer is important enough to rush out Special Climate Statement 55 – prolonged March heatwave affects many parts of Australia – I noticed Canberra mentioned in the table on page 15 and ran a few checks –
The BoM Time Series page (based on Acorn) shows that for NSW and SE Australia March 1940 had the hottest max but in their page 15 table the BoM are quoting successive days over 30 or 35 or whatever.
My chart shows the progression of the days for 1940 vs 2016 and we will see what can be said next month.

And of course we know that few stations have daily data digitised before 1957.

Puzzling why no coalition MP’s or Senators use Senate Estimates hearings to question the BoM about their ACORN temperature data adjustments

Recently Dr Jennifer Marohasy reported on a meeting of MP’s in Parliament House Canberra where the IPCC / Bureau of Meteorology (BoM) position was questioned. Sceptics and Alarmists, Together, Present to Coalition Environment Committee
This got me to wondering why adjustments to temperature data in the BoM ACORN data are never examined during Senate Estimates hearings. All it would take is an MP or Senator or two prepared to put a bit of actual work into understanding a little series of questions and the spreadsheet data behind them. Senate Estimates hearings are public and segments are often featured on TV news.

Why does the BoM adjusted ACORN temperature series incorporate urban heated Australian capital city data?

Now the the BoM adjusted warmer temperature series ACORN is in news again – thanks to Dr Jennifer Marohasy and Graham Lloyd Environment Writer at The Australian newspaper – it seems a fair question to ask. Surely if you were starting from scratch with BoM raw weather records to build an honest temperature history of Australia – the first step would be to exclude all data known to be urban heat island UHI affected. No? There are hundreds of historic weather records available from sites with less UHI contamination – but the BoM include all Australian big cities. I’m puzzled.

The Australian newspaper publishes another article on BoM scandalous temperature adjustments to Rutherglen data

In the week after the hand picked Govt “review panel” gave the Good Housekeeping “Tick of Approval” to the BoM ACORN temperature data – hoping to sweep the issue away. Great timing by Jennifer Marohasy – links to a fully copy of the article at her site. The article is paywalled at The Australian but if anybody can give me the exact title – it might be found with Google whose links sometimes get through paywalls.
Jo Nova is on to the pathetic BOM Technical Advisory Forum report too – If it can’t be replicated, it isn’t science: BOM admits temperature adjustments are secret
Just Google this – Questions remain on BoM records
gets thru the paywall by magic – thanks to Geoff Brown
This links to a Jennifer Marohasy page with many links to the sensational series of 2014 articles in The Australian critical of the BoM. A first ever for the Australian media.
There is a second article by Graham Lloyd – the title is – Bureau of Meteorology told to improve data handling, analysis – but Google did not get me thru the paywall. Anthony Watts has an article – Progress on the problems with Australia’s ACORN-SAT surface air temperature records – with full text of both pieces from The Australian.

Australian Bureau of Meteorology misleads in defense of their highly adjusted ACORN SAT temperature series

Anybody following the BoM responses to the series of articles in The Australian questioning the ACORN adjustments has heard this old canard from the BoM. “Oh but our adjustments make no overall difference – the raw trends are the same as ACORN trends”. This can only be true by including the cooling corrections the BoM chooses to make moderating the raging UHI’s contamination in Australian city data.

Australian Bureau of Meteorology fails to repair their flagship ACORN temperature dataset as the Director of Meteorology expected

In May 2014 I got a reply from Dr Rob Vertessy, Director of the BoM – to my pointing out that the ACORN-SAT data set had about a thousand examples where a daily MAX was less than the daily MIN. Dr Vertessy said that he expected that these errors would be corrected in an updated version of ACORN-SAT in the second half of 2014.

I just checked ACORN data for Alice Springs back to 1986 and the exact errors discovered by Ed Thurstan in 2013 are still there.


I have not got time to check for a thousand errors so I am assuming the ACORN update is running late. I am not surprised – as I point out in my articles examining ACORN data for Cobar – the ACORN methodology is illogical – relying on computer driven data mining comparisons hundreds of km from Cobar while ignoring data much more adjacent. Cobar ACORN I and Cobar ACORN II. The BoM should save taxpayers some money and scrap the ACORN disaster now.

Australian Prime Minister Tony Abbott famously said “climate change is crap” – maybe he was correct

The Australian newspaper reported that Tony really did say this at Beaufort, Victoria, in December 2009 – Town of Beaufort changed Tony Abbott’s view on climate change
But my posts on BoM adjustments to ACORN-SAT Cobar Meteorological Office temperatures 1963-2013 Episode 1 and Episode 2 – raise a new question.
Follow the logic here. The adjustments the BoM makes in its flagship ACORN-SAT data show that they do not even trust the readings made at Cobar – a state of the art, purpose-built meteorological station, staffed by their own professionals. What they are saying is that for practical purposes it is impossible even for our modern scientific society to measure temperature consistently at a professionally managed site over multi-decades.
Yet temperature data from thousands of stations of vastly lower quality around the world – used without adjustment to prove “global warming” – are bound to carry far more errors that we know little or nothing about. And the adjustments at Cobar alone are as large as the claimed rate of “global warming” over decades.
So whatever the truth of Tony’s assessment of the whole issue, it is difficult to avoid the conclusion that “climate change as measured – could well be crap”.

BoM makes large warming adjustments to minimum temperatures prior 2007 in its own professionally collected Cobar Met Office data but fails to include the 2007 adjustment in their own 2014 published list – Episode 2 Cobar ACORN-SAT

This is the second episode in the Cobar ACORN-SAT series examining BoM adjustments to the CDO temperature data – here I start to look at adjustments to minimum temperatures. The 1st episode looked at maximum temperatures. A list of ACORN adjustments to Cobar data is here and you can see the first min adjustment listed is 1st Jan 1972 meaning the adjustment factor applies to all data earlier than that. You will see it is labelled as “Statistical” meaning there is no evidence for it in station diaries or admin records but it derives from computer driven comparisons sifting data differences from multiple stations as far away as Parkes and Hillston – see map. In this case of the 4th adjustment the following stations data was used.
Making the chart of Cobar annual minimum temperatures compared to ACORN-SAT my eye was caught by the adjustment starting in 2006 and affecting all earlier years which I have marked with a blue 6. That is unlisted in the ACORN-SAT documentation and is substantial at about -0.4 degrees C. The slight mismatch between Cobar Met Office and ACORN from 2007-2013 is due to rounding differences because I have made my ACORN annuals by averaging a year of daily data which I leave as produced by Excel with multiple decimal places.
The next adjustment to look for is at 1971 where I have the blue 4, which is the 4th adjustment in the ACORN list and is listed at -0.49 degrees C. The increased departure of ACORN cooler than Met Office to about -0.9 is obvious on the chart.
Examining this adjustment in greater detail I have made a chart comparing Cobar MO and ACORN version with nearest neighbours Bourke, Wilcannia and Nyngan. The average difference between the 1971 & 1972 readings for these 3 stations is +0.2 at Cobar MO, +0.4 at Bourke PO, +0.4 at Nyngan, and -0.4 at Wilcannia, an average for the 3 Cobar neighbours of +0.13, not very different from the +0.2 that we know happened at Cobar Met Office. But instead of leaving the higher quality Cobar Met Office readings well alone – what does the BoM decide to do with their adjustment #4? They take off 0.49° making the 1971-1972 difference now 0.7 – greater by 0.3 than any of the neighbours. Presumably the BoM justify this by their computer driven comparisons with sites as distant as Parkes.
If the reasons for an adjustment can not be seen in nearest neighbours then it must be an exercise in fantasy to search for a reason in a cherry picked array of more distant stations which are all of poorer quality than Cobar Met Office.
It is interesting to check the differences in annual minimums between Cobar Met Office and Cobar Airport which are only about 7 or 8 km apart. You might expect them to be very similar and in lockstep – not so from the chart.
Note the BoM never refer to Cobar Airport data in ACORN-SAT – but we are free to check it out.
First there is no evidence here of a step or jump around 2006 – 2007.
While there are such wildly varying and apparently random differences between these two very adjacent sites – what on earth can the BoM learn by comparing Cobar with Parkes – or indeed any other station in their adjustments list.
These are the sort of unsafe foundations that pro-IPCC climate science is based on.