Jennifer Marohasy
If most temperatures are the identical, whether or not measured by platinum resistance probes or mercury thermometers, why does the Bureau make an adjustment of 0.5 °C within the homogenisation of temperatures from Cape Otway Lighthouse?
On Friday (third February 2023), I might be showing as an skilled witness within the Administrative Appeals Tribunal in Brisbane. The listening to is a couple of Freedom of Data (FOI) request that has been denied my husband, Dr John Abbot, for over three years. The knowledge, I’ll argue, must be made public, to allow some evaluation of the reliability, or in any other case, of temperatures as recorded at official Australian Bureau of Meteorology climate stations.
Claims that we face a local weather disaster as a result of temperatures will quickly be exceeding 1.5 °C is driving the closure of coal mines, caps on the worth of fuel and a psychological well being epidemic amongst kids who more and more worry international warming.
Temperature measurements as printed by the Australian Bureau of Meteorology, and different such climate bureaus world wide, are on the coronary heart of the priority, as a result of they purportedly present an unprecedented enhance, significantly over current years.
On the one hand, the Bureau claims temperature measurements from the platinum resistance probes, which now substitute mercury thermometers at most official recording stations, are equal and subsequently there isn’t a want for scrutiny of the parallel measurements that exist for 34 climate stations. Alternatively, the Bureau has made adjustments to official temperatures as recorded at Cape Otway Lighthouse theoretically of 0.5 °C for the 84 years from 1910 to 1994 based mostly on this instrument change. In response to the ACORN-SAT Station Adjustment Abstract temperatures have been dropped down from fifteenth April 1994 again to 1st January 1910 by 0.5 °C, citing set up of an automated climate station (AWS) that includes a change from mercury thermometer to probe.
It’s notice worthy that the course of the adjustment contradicts the anticipated have an effect on of fixing to a probe, which might be that the probe would possibly measure hotter than the mercury. That is acknowledged within the Bureau’s personal Analysis Report No. 032 The Australian Local weather Observations Reference Community – Floor Air Temperature (ACORN-SAT) Model 2 (October 2018) by Blair Trewin:
Within the absence of some other influences, an instrument with a sooner response time [a probe] will are inclined to document greater most and decrease minimal temperatures than an instrument with a slower response time [a mercury thermometer]. That is most clearly manifested as a rise within the imply diurnal vary. At most places (significantly in arid areas), it can additionally end in a slight enhance in imply temperatures, as short-term fluctuations of temperature are usually bigger through the day than in a single day.” (Web page 21) Finish quote.
Due to the problem in attaining consistency between temperature recordings from the probes with conventional mercury thermometers the Indonesian Bureau of Meteorology (BMKG) information and archives measurements from each units with a coverage of getting each kinds of tools in the identical Stevenson Display in any respect its official climate recording stations.
You will need to notice that by cooling previous temperatures at Cape Otway by 0.5 °C, moderately than, for instance, rising the worth recorded from the probe every day, the Bureau has been theoretically underneath reporting the temperatures from Cape Otway lighthouse by 0.5 °C since fifteenth April 1994.
This distinction of 0.5 °C – that’s one third of the dread 1.5 °C that’s driving the closure of coal mines, caps on the worth of fuel and a psychological well being epidemic amongst kids who more and more worry international warming – is barely an estimate by the Bureau.
The Bureau can not know the precise quantity as a result of the mercury thermometer was eliminated on the similar time the probe was put in on the climate station at Cape Otway lighthouse. The mercury thermometer that was eliminated on fifteenth April 1994 had been faithfully used to measure most temperatures at Cape Otway lighthouse since 1865 – for 129 years. Data on tools adjustments might be discovered within the Metadata for Cape Otway, accessible on-line.
The Australian Bureau has a coverage of sustaining mercury thermometers with probes in the identical Stevenson Display for a interval of at the least three years when there’s a change over. This coverage, nevertheless, isn’t applied and was utterly ignored on fifteenth April 1994 at Cape Otway.
Whereas the mercury thermometer had been reliably recording temperatures at Cape Otway for 129 years, the probe wanted changing after simply 14 years, on eleventh November 2010 in keeping with the Metadata for Cape Otway.
In response to the ACORN-SAT Station Adjustment Abstract no further adjustments had been made to the official historic temperatures following the set up of the second probe.
It’s subsequently cheap to imagine that temperatures at Cape Otway gentle home, temperatures which can be integrated into international databases used to calculate international warming, are nonetheless reliably 0.5 °C cooler than the ‘actual temperature’, in different phrases the temperature as it could be recorded by a mercury thermometer.
If we add this 0.5 °C to 1.47 °C, which is how a lot the Bureau estimates Australia has warmed since 1910, then the tipping level of 1.5 °C has already been exceeded!
This must be of immense concern to local weather activists. They need to be screaming for an audit of temperature measurements.
As a result of the one method we will know for certain whether or not the tipping level of 1.5 has been exceeded, or not, is that if the parallel knowledge from the 34 climate stations the place the Bureau claims to be recording temperatures from mercury thermometers and temperature probes in the identical Stevenson Display is made public. Then we will know if the probes actually do document 0.5 °C cooler than mercury thermometers that had been traditionally used to measure temperatures.
That is the essence of the FOI request that has been refused: that the parallel knowledge be launched.
The Bureau has variously claimed that it can not make this parallel knowledge public as a result of it could be too onerous to scan all of the A8 Varieties which have the utmost temperatures recorded manually (written by hand onto paper) from the mercury thermometer every day subsequent, to the digitally recorded temperature from the probe. An instance of an A8 Type is supplied in Half 2 of this collection.
Extra lately the Bureau has claimed that it can not make this data public as a result of it does not exist, or variously that an A8 Type isn’t a doc and subsequently not topic to John Abbot’s FOI request. All of the whereas the Bureau’s director, Andrew Johnson, writes to me that the measurements from the probes are equal to the measurements from the mercury.
Following the intervention of then Setting and Power Minister Josh Frydenberg again in October 2017, I used to be supplied with over 10 681 scanned A8 pages for the interval from 1 January 1989 to thirty first January 2015 for the official climate station at Mildura. With the help of colleagues, I manually transcribed over 4 000 of those A8 Varieties starting 1 November 1996.
Evaluation of this knowledge signifies that the primary probe at Mildura did certainly document temperatures too cool relative to the mercury thermometer, however the third probe that’s now in place information temperatures too scorching typically by as a lot as 0.4 °C. If that is certainly the case extra usually at climate stations throughout Australia, then it’s attainable that the tipping level of 1.5 °C might have already been exceeded and by greater than two complete levels Celsius, particularly by 2.37 °C (1.47 + 0.4 + 0.5).
We will solely know if the parallel knowledge is made public, facilitating a extra correct evaluation of the change in temperatures throughout the landmass of Australia since at the least 1910.
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SUPPLEMENTARY NOTES/ CLARIFICATIONS
The 1.5 °C tipping level is often understood to be a imply temperature which is the typical of the minimal in addition to the utmost. Within the above publish I’ve in contrast it relative to only the utmost temperatures at Cape Otway as this weblog collection focuses on most temperatures. Of notice, an issue evaluating with the imply is that the alcohol thermometer, which measures minimal temperature, was additionally faraway from the Cape Otway climate station in 1994. The Bureau solely appeared to switch the utmost in 2002 and for a interval of simply ten years.
Whereas the 2014 ACORN-SAT Station Adjustment Abstract claims that the one change to Cape Otway most temperatures for the interval earlier than 15 April 1994 is a dropping-down of 0.5 °C, in actuality, scrutiny of the ACORN-SAT knowledge relative to the unique measurements exhibits the adjustments to be extra complicated than that. Chris Gillham who owns WAClimate.internet has emailed me:
Every day is handled in a different way by the algorithm inside ACORN-SAT.
For instance, Cape Otway …
6 January 1985
ACORN 2.3 : 15.4C / RAW 16.0C7 January 1985
ACORN 2.3 : 17.6C / RAW 18.0C8 January 1985
ACORN 2.3 : 18.3C / RAW 18.5C9 January 1985
ACORN 2.3 : 15.9C / RAW 16.5C15 April 1994
ACORN 2.3 : 17.0C / RAW 17.2CACORN cooling these 5 days by 0.4C on common.
Alternatively …
6 August 1931
ACORN 2.3 : 11.0C / RAW 10.8C7 August 1931
ACORN 2.3 : 11.0C / RAW 10.8C8 August 1931
ACORN 2.3 : 11.9C / RAW 12.3C9 August 1931
ACORN 2.3 : 12.9C / RAW 12.8C10 August 1931
ACORN 2.3 : 14.1C / RAW 14.3CEach 12.2C on common.
Thoughts you, ACORN v RAW dailies by no means make sense.
All Cape Otway dailies from 1 Jan 1910 to 13 April 1994 common 16.7C in ACORN 2.3 and 16.6C in RAW.
All Cape Otway dailies from 15 April 1994 to 31 December 2022 common 17.2C in ACORN 2.3 and 17.1C in RAW.
[end Note from Chris]
I present the impact of the totally different variations of ACORN-SAT on the unique ADAM values in my interactive desk distinctive to this web site, and particularly for Cape Otway right here: https://jennifermarohasy.com/wp-content/uploads/2022/03/Tmax_090015.png
The ADAM values might be discovered right here: http://www.bom.gov.au/local weather/knowledge/
The ACORN-SAT values might be discovered right here: http://www.bom.gov.au/local weather/knowledge/acorn-sat/#tabs=Information-and-networks
Metadata for Cape Otway Lighthouse together with instrument adjustments might be discovered right here: http://www.bom.gov.au/clim_data/cdio/metadata/pdf/siteinfo/IDCJMD0040.090015.SiteInfo.pdf
Within the following tables I annotate the related data in Metadata doc and ACORN-SAT Adjustment Abstract.
Desk 1.
Desk 2.
The ACORN-SAT Station Adjustment Abstract, as supplied to me in 2014 might be downloaded right here.
The characteristic picture on the prime of this weblog publish is of Cape Otway lighthouse. Cape Otway Lighthouse is the oldest surviving lighthouse on mainland Australia. In-built 1848, the lighthouse sits 90 metres above the ocean of Bass Strait.
Filed Underneath: DataTagged With: Temperatures
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John & Suzanne Smeed saysJanuary 28, 2023 at 4:43 pmGood on Ya – Jen, I’m certain you’ll give them hell !Blissful New Yearfond regards JOHN
Sam saysJanuary 28, 2023 at 5:24 pmJenniferHow many situations have the BOM ‘elevated’ historic temperatures?
Patrick Donnelly saysJanuary 29, 2023 at 1:34 amProperly carried out!Exposing lies and obfuscation is tiring. I love your vitality. Keep effectively!
richard bennett saysJanuary 29, 2023 at 7:47 amThe BOM has an actual drawback with reporting precise measured knowledge when it doesn’t agree with the political narrative on local weather. Folks world wide now recognise that the local weather debate has turn into a poisonous narrative on find out how to be a corrupt public sector in a single simple step.
