Jennifer Marohasy
At Cape Otway Lighthouse overlooking Bass Strait, the highest daily January temperature ever recorded is 43.3°C on 24th January 1982, and the lowest January temperature ever recorded is 3.3°C on 2nd January 1900. In between some 30,000 (365 x 82) daily maximum and minimum temperatures were recorded by a succession of lighthouse keepers at 9am each morning, every day of every year.
Across the landmass of Australia men and women have been diligently recording temperatures for more than a century. At Cape Otway Lighthouse daily recordings began in January 1865, and continued until April 1994. At Brisbane airport the record begins in 1929, and manual recordings from mercury thermometers continued until 31st July 2022. Temperatures are now only recorded using a platinum resistance probe by an automatic weather station (AWS) at both Cape Otway lighthouse and Brisbane airport, and most other weather stations spread across the land mass of Australia. To be clear, there are no longer any manual recordings from a mercury thermometer at Brisbane airport, these ceased in July last year.
Many technical people will argue that while a mercury thermometer will still be accurate when it is 100 years old, probes – essentially measuring temperature as electrical resistance, as voltage, through some wires connecting the platinum to a data logger – will suffer from corrosion and electrical noise soon after installation and thus the recordings are less stable and will also drift especially in harsher environments.
Meanwhile, I’m often told, especially by ordinary folk, who confuse the Bureau’s probes with digital thermometers, that an AWS is surely more reliable because it will capture the exact hottest time of day, and because these instruments are more precise.
It is the case that even though the highest temperature in any 24-hour period occurs in the afternoon, maximum temperatures are manually read from a mercury thermometer at 9am the next morning. Then the thermometer is reset, by shaking, that causes the column of mercury to collapse back down into the tube, only to rise again as air temperatures rise during the day. The column of mercury will rise to the highest air temperature and become temporarily ‘stuck’ by a constriction in the tube with some 40 seconds or so of inertia. Measurements from a mercury thermometer are less spikey than measurements from a probe. Nevertheless, a mercury thermometer will capture the highest daily temperature, as long it is manually read and reset every day.
Despite the large range in daily temperatures – 40°C at Cape Otway Lighthouse and many other Australian locations – I am always surprised at the consistent patterns that quickly emerge, including in geographically distant locations, when I crunch Australian Bureau of Meteorology temperature data converting daily temperatures to monthly and yearly averages, and so on. At least this is the case with temperature data for the period from about 1908 up until about 1996, which is the period when temperatures were recorded using mercury thermometers in Stevenson screens across Australia. The data is more reliable for northern Australia back another 20 or so years, because from the late 1880s Clement Wragge, against the advice of southern meteorologists, was replacing Glaisher stands with Stevenson screens as the official shelter for mercury thermometers. He was always ahead of his time and sacked with the creation of the Australian Bureau of Meteorology in 1906, and fled Australia in 1907. Wragge had been appointed Government Meteorologist in Queensland in 1887 and by 1893 had established 16 first order meteorological stations, 36 second order stations and 45 third order stations and 398 rain stations. Queensland thus has some of the best and longest temperature records for anywhere in the world, that were assumed by the Australian Bureau of Meteorology in 1906.
Cape Otway and Wilsons Promontory Lighthouses, both in Victoria, had Stevenson screens installed in 1902 and 1905 respectively. I crunched the numbers on these temperature series for a scientific paper that I had published with John Abbot in the international climate science journal Atmospheric Research in 2015.
We began that research paper with mention of one of the first detailed studies of climate change in Australia that was by E.L. Deacon published in the Australian Journal of Physics back in 1953. Deacon identified a period of significantly higher mean summer maximum temperatures during the period 1881 to 1910, than during the subsequent period 1911 to 1940. This early study, based on measurements from mercury thermometers, concluded that ‘the good consistency of the changes suggests the cause to be mainly climatic rather than changing observational technique or exposure’ (p. 213). To be clear, the professor was claiming the thirty years before 1910 to be hotter than the next thirty. The graphs in the Deacon study show cooling to circa 1950 and I report this same result for Cape Otway and Wilsons Promontory in our 2015 study. Modern reconstructions more usually have stripped away the cycles and show a mostly consistent linear temperature increase from 1910 consistent with global warming theory.
Back in 2015, I was continually trawling through the Bureau’s online raw temperature database constructing long and continuous temperature series, seeing cycles of warming and cooling, often corresponding with periods of drought and flooding respectively, and assessing these temperature series against various criteria including the skill of the monthly rainfall forecasts that I was generating with John Abbot.
Back then, we were working on a new technique for forecasting monthly rainfall using artificial intelligence. John would feed the temperature series, along with temperature and pressure gradients from the Pacific Ocean, into his computer program that used artificial neural networks (a form of artificial intelligence, AI) to generate monthly rainfall forecasts. At the time, it was easy to show that our seasonal rainfall forecasts were more accurate than equivalent forecasts made by the Australian Bureau of Meteorology using a supercomputer. Our comparisons were published in the peer-reviewed literature.
In 2015, when I was assessing the quality of long, continuous temperature series as input to the artificial neural networks that John Abbot and I were using to forecast monthly rainfall, I wrote to the Australian Bureau of Meteorology asking for parallel data. I knew that at both Cape Otway and Wilsons Promontory lighthouses, the Bureau had transitioned from having the lighthouse keepers record the maximum temperatures from the mercury each morning, to having the temperatures, I initially thought, also recorded automatically from a platinum resistance probe. I wanted both sets of measurements and to compare them.
I subsequently discovered that the mercury thermometers were removed on the very same day the probes were installed. At Cape Otway lighthouse the mercury thermometer was removed on 15th April 1994. This mercury thermometer had been faithfully used to measure maximum temperatures at Cape Otway lighthouse since 1865, for 129 years! Then suddenly this beautiful (I see beauty in some number series), long and continuous temperature record was ruined, by the change in measuring instrument.
I remain concerned that the Bureau has an unconventional approach for recording temperatures, taking one second extrema rather than numerically averaging measurements over one minute as is recommended by the World Meteorological Organisation.
It is important to average readings from the probes, if they are to be comparable with readings from mercury thermometers, because the mercury thermometers respond more slowly to temperature change on a minute-by-minute scale.
The Bureau has a policy of maintaining mercury thermometers with probes in the same Stevenson screen for a period of at least three years when there is a change in site or equipment. This policy, however, was completely ignored on 15th April 1994 at Cape Otway. And while the mercury thermometer had been reliably recording temperatures at Cape Otway for 129 years, the probe that was installed needed replacing after just 14 years, on 11th November 2010.
Without any parallel data to make the comparison, the Bureau nevertheless, in 2014, made changes to the temperature series at Cape Otway Lighthouse during one of many subsequent routine remodelling of this data in the creation of the official ACORN-SAT series that is used to report on climate variability and change in the Bureau’s annual climate statements.
Specifically, temperatures at Cape Otway were dropped down by 0.5 °C for the 84 years from 1994 when the probe was installed, back to the beginning of the official ACORN-SAT record that only begins in 1910. According to the ACORN-SAT Station Adjustment Summary published at that time, the temperatures were adjusted/dropped-down from 15th April 1994 back to 1st January 1910 by 0.5 °C, citing the ‘cause’ for the discontinuity in the temperature series as installation of an automatic weather station (AWS).
It is noteworthy that the direction of this adjustment contradicts the expected effect of changing to a probe, which would be that the probe might measure warmer than the mercury. This is stated in the Bureau’s own Research Report No. 032 by Blair Trewin:
In the absence of any other influences, an instrument with a faster response time [a probe] will tend to record higher maximum and lower minimum temperatures than an instrument with a slower response time [a mercury thermometer]. This is most clearly manifested as an increase in the mean diurnal range. At most locations (particularly in arid regions), it will also result in a slight increase in mean temperatures, as short-term fluctuations of temperature are generally larger during the day than overnight.” (Page 21)
In more recent iterations of ACORN-SAT, the Bureau has changed this ‘adjustment’ for the Cape Otway lighthouse temperature series to minus 0.54 and removed reference to the automatic weather station, now claiming the change is made for statistical reasons – all the while not listing the statistical test undertaken or the level of statistical significance. The statistical difference was apparently ‘discovered’ by comparing temperatures as measured at Cape Otway lighthouse with temperatures at up to 10 ‘nearby’ reference stations.
It is impossible to know the exact difference between the maximum temperatures as recorded by a mercury and probe at Cape Otway lighthouse because no parallel data exists.
There exists, however, parallel temperature data for 38 locations spread across the landmass of Australia. After three years of wrangling, then an appearance at the Administrative Appeals Tribunal on 3rd February, John Abbot was able to establish that 15 years of parallel data exists for Brisbane airport, and he was provided with just three years (August 2019 to July 2022) of this data on the Thursday before Easter.
It took me two days over Easter to transcribe these manual recordings, that had been diligently entered at 9am each morning for every day (bar two) of that three-year period by Bureau employees at Brisbane airport.
Once I digitised these values, I tested them for statistical significance and found the temperatures as measured by the probe were significantly different from the temperatures as measured by the mercury (n=1094, p<0.05).
This is not surprising given the spread of values that are not randomly distributed with the probe recording hotter than the mercury 41% of the time, recording the same 32% of the time and lower 26% of the time.
On two occasions the probe recorded 0.7°C warmer than the mercury.
For the first five months of data (August to December 2019) the probe records cooler than the mercury at Brisbane airport by a daily average of 0.2C. From January 2020, the probe records on average warmer by 0.15C. The overall daily difference is some 0.35C.
These findings are not consistent with claims made by the Bureau that there is no public interest in releasing the parallel data because the temperatures are the same whether measured by platinum resistance probes in automatic weather stations or more traditional mercury thermometers.
****
The feature image is a photograph from page 4 of The Weekend Australian from last Saturday. You can read the article online, click here.
These shysters need to be brought to account for their shenanigans … If Dutton wants to improve his party’s electability it’d better start supporting these initiatives to shine light on the BoM grifters.
Good work by Jennifer. Raw data should never be shielded from the public. Wonder how much the mis-match between mercury and Pt probes varies around the world? It seems logical that a semi-continuous Pt probe picks up a higher max temerature if the mercury is read in the morning, so we know nothing about the true max during the mercury phase.
Hi Ron,
There is an important study by X. Lin and K.G. Hubbard (International Journal of Climatology, Volume 28, Pages 283-294) that, from memory, suggests a 1C increase in US temperatures from the probes at some sites even with the numerical averaging.
I would so like to see some parallel data from a few different sites in the US and also the UK.
“I subsequently discovered that the mercury thermometers were removed on the very same day the probes were installed. At Cape Otway lighthouse the mercury thermometer was removed on 15th April 1994.”
There was a reason for that. The lighthouse itself was decommissioned in Jan 1994, to be replaced by an automatic light. So no staff to red the mercury, and the location is isolated.
Google aerial view shows a carpark with maybe 20 cars from tourists plus a cafe , a good access road of course
isolated means many different things in Australia
There was no cafe there in 1994. The LiG needs to be read several times a day (9am, 3pm, min/max reset). The nearest town is Apollo Bay, 33 km away. Where would they get staff to read it (as a secondary measure)?
Max and min read 4 or 5 times a day?
I thought it was only required at 9am …this is for the parallel readings . The automatic thingy does the rest.
Remember this was one of the earliest manned lighthouses and as a result had a very long weather and temp readings in one location.
Not that such things matter to BoM
Great Ocean Rd , was a very popular tourist trail even back before the 1990s . I must have been along there myself was easy access,
Readings could have been delegated to the nearby farming station, their lives were intertangled with the light house keepers anyway over the decades before the highway came in the 1930s
I guess the decision to close the lighthouse was made in secret and implemented overnight leaving the BOM no choice …
Normally these things are known years in advance inclusive of the time required to install an automated light allowing an organisation that actually cared about the accuracy of its instrumental record to run the automated temperature recorder in parallel in accordance to its own rules.
The kind of AWS that they installed before 1994 was in effect a trial version. Most early ones were soon replaced. So not much use doing parallel tests.
That’s probably to most bizarre piece of reasoning I’ve ever read. Precisely because it is a new prototype is the reason any science based organisation would want to maximise parallel running with the system it was replacing.
Why? If it is a trial version, it isn’t going to last long, and they were soon replaced when better AWS became available. So you have put a lot of effort into finding the difference between an LiG and the soon to be replaced AWS.
Why bother collecting data at all, since you are happy to put a device in place that you have absolutely no confidence in and haven’t calibrated it against reality?
What effort? If you’d replaced it in advance of the termination of the lighthouse the normal manual data gathering would take place and you’d have a basis for correcting the prototype you’ve entrusted to record the data when the manual process ends.
You are actually advocating for the opposite of what any sensible organisation deploying a prototype would sensibly do.
Seriously you should ask politely for this whole conversation to be deleted, there is no way back from here for anyone to do anything other than question either your sanity or your ability to conduct rational science.
“since you are happy to put a device in place that you have absolutely no confidence in”
You seem to have lost track of the conversation. You were proposing that an AWS should have been put in prior to 1994, to run in parallel with the long standing LiG. I was explaining why that would not have been feasible.
“You seem to have lost track of the conversation.”
“I was explaining why that would not have been feasible.”
On the contrary I’m fully aware of the “track” of the conversation.
You are doing your normal schtick of using bluster based on semi-plausible claims to try to shield your team for justified claims of gross incompetence.
As for explaining why it wouldn’t be feasible your pathetic efforts include:
1) It wasn’t possible because the lighthouse became automated – utter garbage given that the decision to terminate the employment of the caretaker and the installation of automated lighthouse operation would have been years in the making easily allowing significant parallel running prior to the end of the caretaker’s employment
2) It’s a trial version – beyond stupid – the fact that it is a poorly understood device is precisely why you need to have a good model of its performance to maintain the continuity and integrity of the temperature record.
3) But it’s not going to last long – more daft reasoning. It’s the only thing that will be measuring the temperature, a good model of its performance leading up to its replacement – with parallel running with the replacement system gives the greatest chance for accuracy.
No parallel running means you really just don’t care about data accuracy, probably because the shysters you seek to protect are just going to mangle the data any way they like anyway.
I expect you’ll respond with a link to the BOM “methods” doc, which though it explains the individual methods they use does not provide any basis for replication of their manipulations because the decisions they make for which of their various manipulations they apply are totally arbitrary and agenda driven. They know the result they want and they have a variety of techniques to achieve it.
“allowing significant parallel running prior to the end of the caretaker’s employment”
You have lost the plot. My point is that if they were to have that parallel running, an AWS would have had to be installed about 1991. Now AWS’s were generally not being installed at that time in Australia. They were waiting for a standard that they could continue with. There would be no purpose in going to that trouble and expense just to have two instruments in parallel, when whatever you learnt would be useless when the AWS was updated.
Oh Nick, still defending the indefensible. The BOM temp network is shot to bits just like NIWA’s. The only thing warming in this world is the fevered imaginations of the alarmists.
“There would be no purpose in going to that trouble and expense just to have two instruments in parallel”
Other than having an accurate continuous temperature record for the site, which I would have thought would be the only important thing the BOM should have been interested in.
There is an accurate continuous temperature record for the site.
You really are a full blown clown. You’ve already admitted to the fact that the recording equipment was a temporary electronic setup that was soon to be replaced and was never parallel run in accordance to the BOMs own requirements for site equipment. You can’t make this statement with any certainty, but of course you still do.
“You’ve already admitted to the fact that the recording equipment was a temporary electronic setup that was soon to be replaced”
You seem to be unable to read or listen. The equipment to April 1994 was a LiG thermometer. The equipment since then was an AWS, which is still there. The record is continuous. The harebrained idea of introducing an AWS before 1994 was yours alone. It didn’t happen.
THE point is that at some sites there are TWO measurement instruments giving different results.
Whenever you measure anything with two different instruments you’ll get different results. Try it with bathroom scales. The relevant question is, different by how much.
Nick Stokes April 22, 2023 2:35 am
Now, the mercury thermometer record at the lighthouse ends on 18 April, 1994.
I find the following:
So they put an AWS in at Alice Spring Airport in 1991 but they couldn’t put one in the lighthouse???
I also find:
and
and in Antarctica
Finally, from the Australian BOM:
Taken together, this makes it clear that by 1994 there were a number of AWS systems in operation. 14 of them were in operation prior to 1991.
As a result, I find it extremely unlikely that the BOM couldn’t have installed an AWS in the Cape Otway Lighthouse in say 1991 and run parallel with mercury for three years.
w.
Willis,
“105 of the 112 weather stations in ACORN are AWS, their average start year 1996. Of those 105 AWS installations, 14 were from 1986 to 1991, 66 from 1992 to 1999, and 25 from 2000 to 2018″
Clearly they were rolling out AWS in those years. But why would the give Otway priority to run in 1991 as a secondary instrument where they are clearly occupied installing them elsewhere as primary instruments.
Ummm … so they could determine the offset between the AWS and mercury at that site? Plus to make it so there was no 10-month gap in the records?
You know, the kind of bozo simple stuff you do to ensure that your data is worth more than a bucket of warm spit?
w.
Precisely Willis.
i was curious about the BOM reasoning in ruling on the FOI release by the AAT ( appeals tribunal)
This is the BOM web page of the logs for the FOI releases and the actual data
http://www.bom.gov.au/foi/disclosure.shtml the link downloads a zip file
The actual reasons for decision for FOI 30-6155 dont yet seem to be available or the case search functionality isnt working
Hi Duker, My understanding is that because the data was released following a mediation, there will be no decision. It was complicated. I am not allowed to comment on what happened as part of the mediation.
The last time I looked, the BOM is 100% tax payer funded. As a financial contributor to their data, I’d like to see it.
If it’s secret, then I demand to NOT be paying for it. I want my money back. With back pay.
Jennifer,
“This is an extract from the Bureau’s ‘ACORN-SAT Station Adjustment Summary’ that was provided to me via journalist Graham Lloyd in 2014. This document is not publicly available and has been updated since 2014, with the changes that are regularly made to the ACORN-SAT data base.”
You don’t seem to look very hard before making these declarations. The document is publicly available here. Here is an extended picture of that page:
http://www.bom.gov.au/climate/change/acorn-sat/documents/ACORN-SAT-Station-adjustment-summary.pdf
Just choosing a place – Port Hedland for example has 11 different adjustments made to the raw data
Busy little elves
I was always told to NEVER adjust the raw data. You present it and if you observe some obvious errors then you make a revised copy of the data that corrects the errors.
I was taught that you must provide a basis for your corrections and make this available for others to review.
It would appear that the BOM are keen to adjust the raw data, not publish their methods and also make the original data difficult, if not impossible to locate.
So why do they do it? Is it for money? Is it for prestige? Is it under direction? Is it one or many doing the adjustments or directing them? Surely, the changes are documented and auditable? If not, why not?
“not publish their methods”
Of course they publish their methods.
“also make the original data difficult, if not impossible to locate”
Of course they make the original data easy to locate. Better than any other country I have seen.
But there is a portal here which makes it even easier.
Un-scientific fraud.
So why restrict the hand written raw data from Brisbane airport , that was collected in parallel to the automatic method
If it exists , isnt exempt – which it isnt , then it must be released
“which it isnt , then it must be released”
This was a decision by the Administrative Appeals Tribunal. Presumably they are aware of the relevant law.
From the handbook:
Another approach is to consider locations where automatic and manual observations took place at the same time at the same place, or in very close proximity. There are nine such locations with potentially suitable parallel observations: • Cape Byron (28.64 °S, 153.64 °E) and Marble Bar. At these sites, manual and automatic instruments were in the same screen but their data were archived under different station numbers.
This Marble Bar: ACORN adjustments robbed Marble Bar of its legendary world record. Death Valley now longest hottest place « JoNova (joannenova.com.au)
Duker said “Busy little elves” – I would add “Busy little data-mining elves” – data mining for over 1,000km around if required.
Good to know it is online. Thanks. Cheers.
Nice work.
I can’t believe the perfidy of the Bureau. Imagine, replacing less accurate, old tech, with new, more accurate tech.
Is there nothing they will not do to ruin civilization? For shame!
You missed the point.
Ah statistical changes. Statistics can’t tell you what the temperature was yesterday, let alone on any day 100 years ago.
This algorithmic adjustment of records based on differing data from ‘nearby’ stations is very likely completely unjustifiable.
Isolated hot or cold pockets of air can be detected within small areas of very similar environments.
Contract chicken growers have pretty sophisticated shed climate controllers in their multi-million dollar setups, and keep a very precise record of temperatures.
A Lockyer Valley farmer informed me that different contractors farms in a 10 to 15 km radius can record a daily maximum of 1 to 2 degrees warmer than that recorded in other contract farms in the surrounding area with similar topography.
For recent very dense temperature data sets around capital city regions, it may by fruitful to contact larger corporate poultry production companies, as they have a huge network of contract growers with technical environmental monitoring setups.
“This algorithmic adjustment of records based on differing data from ‘nearby’ stations is very likely completely unjustifiable”
Yes, but needed by the Climate Cult
What a refreshingly well put together article It will be near impossible to argue with that withouty providing alternative hard data. The more media coverage the better
Problem is here that what’s been alluded to and pointed is, is Massive Hole in the entire theory of Green House Gases
‘hole’ is me being diplomatic – it is Huge and Blatant Lie
The Theory asserts that The Atmosphere is transparent to incoming solar radition, even though Trenberth’s Cartoon shows and incoming absorption of ~78Watts
Total bollox.
The air absorbs immense amounts of solar radiation unless it is clinically critically absolutely Bone Dry. I’ve no idea what number to suggest but it has got to be well less than the amount of CO2 we have ever recorded or guessed at
The problem with the electronic probes occurs on days when the sky is mostly cloudy (white fluffy clouds) but with brief spells of very bright sunshine.
Those bright spells heat the air to a level easily 1 or 2 Celsius above what any thermometer had been recording while under a cloud, but just for a few moments.
(Ask people who’ve ever visited a solar eclipse = how fast the air cools when the sun disappears and how fast it warms up again afterwards)
But those minute-long peaks get recorded as ‘actuality’ by the electronic probes whereas the Mercury probe would have ridden through them like a steam-train hitting a minor snowdrift
And when the Daily Average is calculated from the (Max+Min)/2 the daily average is seen to be higher.
It’s pointing to another Perfectly Fatal Flaw in the Green Hoese Gas Model = the relentless and deliberate confusion of Temperature with Energy
I suspect others have tried this. But I have experimented with determining the “ average temperature “of my back yard at any given moment using multiple thermometers in different locations. Tried all different types of thermometers. Getting devices that are equal and can be calibrated was a cost issue , the electronic ones with remote sensors were not accurate. Old fashioned simple bulb thermometers were the easiest to calibrate by moving the tube in the mounting. Choosing locations in my partially wooded yard also created issues. After awhile I determined the lack of precision made the project futile and I gave up.
Older poorly made mercury thermometers would start drifting lower from the date they were manufactured and if they were only read at 9am they’re not gonna show the pre-dawn minimum temperature at all. Newer mercury thermometers (1900-ish) must be slung down then given time to return to temp – nobody’s got time for that so they just read it and walk away. The newest ones aren’t gonna be manufactured by someone making $20 an hour so they come from places where the manufacture is still questionable and “good enough” is let through.
Platinum against liquid mercury in an otherwise sterile environment won’t corrode past the first amalgam layer https://pubs.aip.org/aip/jap/article/51/10/5555/960843/A-kinetic-study-of-platinum-mercury-contact
I agree with the people stating that the new automatic thermometers allow cherry picking of the absolute maximum of the day. There can be no other reason for the use of such devices.
However, accessing the data and finding the actual 9am temp shouldn’t be too hard and the moment these newer stations don’t agree with a modern properly operated mercury thermometer they can be ignored – I would go so far as to say sued for fraud.
Yes, and just so so many extraneous variables in the real world over time and geographic space- plus the human extraneous variables , I remember our oceanography field trip in HS: go out and measure and come up with average temp turbidity etc in that tidal estuary or creek! impossible
The temperatures recorded are not necessarily the 9am number(s).
The thermometer has a feature where it can store both the highest recorded temperature and the lowest. At 9am each day, these two points are recorded and the thermometer reset ready for another day.
9am is chosen because it is likely after the lowest point for the day and also before the peak. 9am is also within the typical working hours of people on site.
Just to be clear, the numbers recorded are NOT the 9am temperature, they are the peak and trough values of the preceding 24 hours.
yes. Many people are familiar with standard mercury thermometer , I had for many years the one with max and min feature included . Very useful but most are probably unaware.
BOM: [T]here is no public interest in releasing the parallel data because the temperatures are the same.
Jane and John Public: We are interested. Let’s see that data.
BOM: Trust us. Would we lie to you?
J & J P: Trust, but, verify. Oh, by the way, we paid for that data. In other words, it is ours. Hand it over.
BOM (on the phone): Uh, “Renewables” Syndicate, what do we say to them, now?
“Renewables:” Never fear. We’ll get Nick Stokes on it.
“Oh, by the way, we paid for that data. In other words,”
Which data? No-one seems to have noticed, but what Jennifer is kvetching about here is that they didn’t take measurements. You didn’t pay for it.
Here ya go, Mr. Stokes 🙄
*** There exists, however, parallel temperature data for 38 locations spread across the landmass of Australia.
After three years of wrangling, then an appearance at the Administrative Appeals Tribunal on 3rd February, John Abbot was able to establish that 15 years of parallel data exists for Brisbane airport,
and he was provided with just three years (August 2019 to July 2022) of this data on the Thursday before Easter. ***
“Renewables”: See? 😄
So we can defund the BOM and still the temperature reports will come in.
You are really thick or deluded, pick one.
We didn’t pay for this either Nick:
Just like that: the suspicious solar panel disappears. The Bureau of Met experts at work? « JoNova (joannenova.com.au)
The public interest test only comes after the information is conditionally exempt and fits the following categories
• Commonwealth-State relations
• deliberative processes relating to agencies’ or ministers’ functions
• the Commonwealth’s financial and property interests
• certain operations of agencies (such as audits, examinations and personnel management) • personal privacy
• business affairs
• research (by the CSIRO or the Australian National University)
• Australia’s economy
The old min-max mercury thermometer I bought many decades ago had 2 metal “markers” in the U-shaped tube that the mercury pushed up to record both the high & low temps and you used a little magnet to “reset” it by dragging the metal marker down to the mercury, whenever time you chose to do it. No shaking involved.
Mine was different again with a red liquid ( alcohol?) that was pushed up on the min and max sides.
‘Button’ at the top when pushed released the liquid which then moved down to existing temp
GO, DR. MAROHASY! Warrior for truth and data-driven science! Cheering you on from the U.S.A..
(No DOUBT, you are brave, and have been since you were a little girl — just dedicating this to a true HERO and to encourage you to keep on SPEAKING OUT! You go, girl!)
“Brave” performed by Sara Bareilles
Thanks so much Janice. You are very kind. There is no enough of that in our world. And ‘data-driven’ are the key words that we need for science, especially for climate science.
🙂
Such a droll doll. Does not understand metadata; does not understand data homigenisation; does not understand basic statistics, and confused about the Bureau’s PRT probes. Perhaps she also cannot read (https://www.publish.csiro.au/es/pdf/ES19032).
As I said previously (https://wattsupwiththat.com/2023/04/18/jennifer-marohasy-live-on-tntradio-live-mercury-thermometers-versus-probes-in-automatic-weather-stations/#comment-3710777):
Why tell porkies. At your age too?
The song and dance about data that did not exist for Wilsons Prom, Cape Otway and Rutherglen. You never undertook regular weather observations using standard instruments anywhere, either. What about your imaginary friend at Goulburn who could not see the Stevenson screen, even though it was there at the time (https://wattsupwiththat.com/2023/02/12/legacy-electronics-botch-temperature-recordings-across-australia-part-1/#comment-3681141)? Why ignore site changes at Mildura, and the six (not four) Tmax values that were more than 0.5 degC cooler than thermometer values in your data for Brisbane?
Why not for once directly address an issue, such as the invalid use of paired t-tests on autocorrelated data differences?
You should have also worked out that Cape Otway was never a Bureau site, and that thermometers would have been replaced, as needed and at their cost by the Lighthouse Service and Parks Victoria over the last 100 years, without the Bureau having known.
As for Brisbane and Mildura why not simply place your data in the public domain?
Nick Stokes is right. The IPA is wasting money that I and others subscribe, and after reading through all this related inexpert commentary, I’m coming around to the view that they should “let you go”.
All the best,
Bill Johnston
http://www.bomwatch.com.au
Hey Bill,
You write: “Why not for once directly address an issue, such as the invalid use of paired t-tests on autocorrelated data differences?”
I stand by my analysis. I consider this the absolutely most appropriate statistical test.
The BoM won’t declare the test they have done, nor the level of significance.
I know you have written to several statisticians and various others complaining about my use of paired t-tests. You began that campaign some months ago. Can you tell us what replies you have got. What the experts have said?
No one wished to be involved is the answer. Speaking anonymously, one said it is a text-book case of the misuse of a statistical test.
A search of “paired t test assumptions” brings-up 26.7 million hits on 0.38 seconds, and it no secret that:
The paired sample t-test has four main assumptions:
from: https://www.statisticssolutions.com/free-resources/directory-of-statistical-analyses/paired-sample-t-test/
While you are paid by the IPA, hardly anything you write about is well-researched or factual and I just don’t believe that anyone claiming to be a scientist could misuse paired t-tests.
Many other parallel datasets exist that can be used as examples of what not to do. Anyway it is up to you to justify your methods. Give an example of where paired t-tests have been used on serially correlated data.
A problem with discussing technical issues on WUWT (and other forums) is the tribal nature of the interaction. Few people actually understand (i), the complexity of issues under discussion; and, (ii), how important the issues are, and how the the audience is open to being manipulated.
You should place your data in the public domain so your claims can be verified. Otherwise it is fair to say you are hiding something.
How important is a 1-off difference of 0.7 degC (or even two or three of them), when those days are not declared to be ‘records’?
You blow these things up as though they are earth-shattering, when in fact they are likely to occur on 5% of days (at least that is what your misused t-test implies (but you don’t get that).
All the best,
Bill Johnston
Either the temp is increasing or the probes artificially produce higher temps. With concurrent measurements the probes are hotter. The paired t-test is a method used to test whether the mean difference between pairs of measurements is zero or not. It is perfect for what Jennifer did.
Bill,
Time is generally considered a quintessential independent variable. Days and months are time.
That air temperature is measured by a probe, will have no effect on the value measured by the mercury. These two types of equipment are independent.
The pairing occurs because the difference in equipment (probe versus mercury) i.e. the process is measured on the same day, after day, after day.
The mere fact that you must take the time to explain this obvious detail shows that Mr. Johnson is just stalking you, complains about you and contributes no additional value to any argument. Of course as the old saying goes, when the flack increases you are over the target. Confirmed once again.
Wrong doonman,
It shows that as she can’t read, she needs guidance.
All the best,
Bill Johnston
Independent strictly refers to data-differences being unrelated in time. It does nor refer to instruments being different.
Your level of statistical knowledge is zilch and as usual you deviously twist the words to mean something else.
Direct quote:
The paired sample t-test has four main assumptions:
Of one another is of one another is of one another.
Dr Bill Johnston
http://www.bomwatch.com.au
Bill,
Time, that can be measured in seconds, hours, days, months or years etc., is always considered an independent variable.
It is not possible to measure something except at a particular time. You can, if you like, jumble the time series, so the measurements are not analysed in chronological sequence, but it is just not possible to take a temperature measurement that does not have time associated with it.
:-).
Dear Jennifer,
Again:
The paired sample t-test has four main assumptions:
The dependent variable must be continuous (interval/ratio).The observations are independent of one another.The dependent variable should be approximately normally distributed.The dependent variable should not contain any outliers.That time is a sequence is immaterial. The issue is whether your sequence of y-values (the differences you are testing) are independent (i.e., not serially correlated). If values ARE serially correlated, your use of the paired t-test is invalid. It is for this reason that the paired-test is not generally used on time-series. The real test is whether the means are statistically different, not whether individual data points are different.
I have previously provided an example using overlap data for Halls Creek. In that case the paired t-test found the mean-difference was highly significant (P <0.0001). But hang on, the mean-difference was only 0.04 DegC (the means were 33.52 vs. 33.48! (N=1571 data-pairs)). A t-test for equal means showed they were the same.
If the means (of the populations of values) are NOT different it cannot be argued that the instruments have a measurable effect on trend or other attributes of the data.
There are several graphical and statistical methods for testing autocorrelation in your differenced data.
While there has certainly been a tribal response to me criticizing you claims of significance, the test you are using is simply not fit for purpose. Having argued this thing with you for the best part of a decade I’m out of patience. You are misleading people (including the IPA) into believing something that is unlikely to be true.
I have no doubt the BoM monitors WUWT.
Therefore, they are in a position to convince the Minister and others that your conclusions are unsound and thereby cause the wind to rapidly blow out of you sail. My question to you is what do you hope to gain?
All the best,
Bill Johnston
“These two types of equipment are independent.”
You are completely missing Bill’s correct point. The daily data is highly autocorrelated. Here is Andy May explaining why you just have to take account of that in statistical testing.
However, the even more cogent point is that the statistical test does not establish anything useful. These are two different instruments – no-one expects them to be exactly the same, as your test aims to disprove. They key question is not whether they are different, but by how much do they differ, You say you have tested the mean, but never said accurately what the mean is.
Lol; I’m losing faith in you Nick. Temp data from 2 different recording instruments is highly autocorrelated? How.
Neither you nor Jennifer seem to know what autocorrelated means. It means each day’s reading, of each instrument, is part-predictable from the previous days. Each day is not independent of the previous. So Jennifer’s assumption that each day is an iid is wrong. This makes significance harder to obtain.
Hahaha; so NO temp record is worth anything. The point is we have 2 types of temp record with one hotter than the other; and guess which one the alarmist BOM is using. Also, Nick, comment on the changes to past temps which the BOM is doing.
You used to be fun Nick. What happened.
At Brisbane the probe was about 0.05C hotter. At Mildura, it was about 0.15C cooler.
BoM does not change past temperatures. It does produce the ACORN series, where temperatures are adjusted to be representative of their regions.
One is unlikely to be hotter than the other.
Read my reply to Jennifer.
Cheers,
Bill
Mr. Johnston,
If your intent was to establish the fact that those who oppose Dr. Marohasy are boorish, self-interested, knaves, you succeeded brilliantly.
Good for you to provide such clever, powerful, support for her efforts on behalf of all Australians.
With a bemused smile,
Janice
Embarrass the BOM isnt a reason to decline the Brisbane airport hand written data
Cape Otway measurements may have been read by the lighthouse service but doesnt mean the data wasnt intended for the BOM. Governments services didnt work in silos as much before the 1960s. Many places like rural post offices also had readings done by postmaster etc
refer Meteorology Act 1906 where the Chief Meteorologist could use State Officers to provided data
5. The Governor-General may enter into an arrangement with the Arraugements S . f 1 f 11 . with State {:tovernor of any tate m respect of all or any 0 t le 0 owmg Governments. matters :- (a) The transfer to the Commonwealth, on such terrns as are agreed upon, of any observatory and the instruments, books, registers, records, and documents used or kept in connexion therewith; (b) The taking and recording of meteorological observations by State officers; (c) The interchange of meteorological information bet.ween the Commonwealth and State authorities;…etc etc ( its old document scanned into digital form)
http://www.bom.gov.au/climate/averages/tables/cw_090015.shtml
Youll notice they include back to the 1860s, not just after 1906 when the Commonwealth Meteorologist was appointed . I dont think it became a bureau till much later
Good lady, the world of meteorology owes you a huge debt for your unending work, first in prying the data away from the pluted bloatocrats at the Australian Bureau of Meteorology, and second, for analyzing, studying, and reporting on your findings.
Well done, that woman!
My best to you and yours,
w.
Dr Jennifer Marohasy said [The data is more reliable for northern Australia back another 20 or so years, because from the late 1880s Clement Wragge, against the advice of southern meteorologists, was replacing Glaisher stands with Stevenson screens as the official shelter for mercury thermometers.]
If you read my little 4 page paper “Comment on D.E. Parker, “Effects of Changing Exposure of Thermometers at Land Stations.” International Journal of Climatology, Vol. 15, pp. 231-234.”
http://www.warwickhughes.com/papers/ozstev.htm
Summing minutes from the three Intercolonial Conferences held in 1879, 1881 and 1888. You see there was much evidence of the use of the Stevenson Screen in the Oz colonies, NZ and Fiji.
While Mr Wragge was indeed a great enthusiast for the use of the Stevenson Screen – maybe “diplomacy and tact” were not his strong points.
In 2010 I posted photos I had evidencing early use of the Stevenson Screen here.
Late 19th Century photographic evidence of the Stevenson Screen in Australian meteorology
http://www.warwickhughes.com/blog/?p=604
Upon examination, it’s even worse than I’d thought.
The last day of the mercury thermometer at Cape Otway was April 18th, 1994.
But the electronic thermometer didn’t begin recording until February 2nd, 1995.
Source: KNMI
Grrrr …
w.
Not true. The last day of thermometer was 14 April 1994. The probe was installed 15 April 1994
There were some teething troubles; the lighthouse itself was closing down in 1994, to be replaced by an automatic. There is about a month of data missing:
Nick Stokes April 22, 2023 4:55 pm
Not according to KNMI. Their record shows data to 18 April 1994. Then there’s a gap until 2 February 1995.
So no, the record is not continuous. There’s a ten month break in the data. Here’s the KNMI data
w.
Well, after reading Bill Johnson’s points, I thought that ChatGPT might be of interest in this question. Here’s what it said:
Hmmm … upon contemplation, I realized I might have asked the wrong question. So I went back to the well:
Double hmmm …
So I thought I’d ask Bard, the Google AI;
Similar, but not the same.
Triple hmmm …
w.