Which causes more summer heatwaves: carbon dioxide or Bureau of Meteorology (BOM) adjustments?
Ken Stewart has analyzed the adjustments used to create the all-new ACORN wonder dataset and compared them with another BOM dataset called AWAP, and finds, extraordinarily, that the trend in average summer maximums has been tripled by adjustments that the BOM imply are neutral.
Since summer maxima are the ones used to generate the most headlines in Australia, I ask again if the Bureau of Meteorology is a scientific agency or a PR group? Increasing the trend in summer maxima would produce more headlines of hottest ever month, season, heatwave, and weekend.
In this graph Stewart splits the data into months, and compares the trends in maxima in the AWAP and ACORN datasets, across the entire nation. We see that most of the adjustments happen to data from the hottest months of the year, October to March. Even though the measured maxima in February and March are possibly cooler now than they were in the early 1900s, they have been adjusted to show warming trends.
When was the last time you heard the BOM tell you that their “hottest ever” February record depended on adjusting down the [...]
Rutherglen is one of the seemingly best stations in Australia, apart from a break from 1955-1965. Bill Johnston looks closely at the raw data, finding that there is probably no trend — flat temperatures — rather than either cooling or warming. And that it’s difficult to fill in data from surrounding stations. He speculates that something fishy goes on in 1924. He also finds that rainfall probably drives a fifth of the temperature swings. He discusses his disappointment at the intellectual level of debate on The Conversation.
Because he knows the area, he also talks about the effect of wet years and dry years, and how that affects winter and summer temperatures. He has a dry wit, and lovely casual style.
I think that if we have to rely on statistical analysis to “know” whether data was shifted or moved when there is no documentation suggesting it was, all certainty is shot, and any definitive statement about temperature trends in Australia is a joke. — Jo
The Rutherglen stoush
Guest post by Bill Johnston
The raw trend is very different from the HQ adjustments which are very different from the ACORN [...]
In last week’s news we find — by golly — that the BOM are going to “rush” to set up an oversight panel that they were told to set up back in 2011 or 2012. Hey, it was going to take three years to set up the panel, but now they’re doing it in two! That’s what I call “action”.
So the BOM knows it’s in trouble, and they shift to Stage 2. They’ve avoided the skeptical questions, the FOIA’s, and the request for explanations for as long as they possibly could. But now the mainstream media is involved, something has to change — because nothing is worse than playing out the questions and answers in an uncontrolled way in public. To pack away those contentious points, what better method than by appointing a committee, review panel, or some kind of “independent” assessment? The right committee can produce toothless recommendations, vague praise, and a weak slap on the wrist and it can take years to do it.
Thus and verily do Ministers sometimes palm off problems, and responsibility. All decision-making power seemingly goes to the “review” (unless it somehow produces an undesirable result). Should the review churn out the conclusion the [...]
Bottom line: The BOM has added a page listing “Adjustments”. It’s two years late, inadequate and incomplete. Skeptics shouldn’t have had to ask for it in the first place, and we still don’t have the algorithms and codes, or rational answers to most questions. No one can replicate the mystery black box homogenisation methods of the BOM — and without replication, it isn’t science. There is still no explanation of why an excellent station like Rutherglen should change from cooling to warming, except for vague “statistics”, or why any station should be adjusted without documentary evidence, based on thermometers that might be 300 km away.
Lo and behold, the pressure from The Australian and independent analysts means the BOM has made a weak belated attempt to do what it has implied it always has done. When Michael Brown provided cover for the BOM he said the notion that scientists were hiding data was “pseudoscience”. The BOM, meanwhile, added a page called “Adjustments”, two years after launching “ACORN”, quietly admitting that the skeptics were right. They did not correct Brown’s baseless namecalling. Other apologists for their inexplicable anomalies, major adjustments or errors – like David Karoly — demand the skeptics [...]
Once upon a time, Australian climate scientists discussed and published climate trends of the late 1800s. And lo, the long lost hot weather decades were apparent in many places in inland South Eastern Australia. While skeptics are accused of cherry picking data from Bourke, Rutherglen and Deniliquin, there are plenty of other examples. In the last post, the 1953 Argus story described hotter drier summers in Omeo, Bendigo, Hay, Bourke, Alice Springs, Echuca, Albury, and Cooma. Here is a Deacon et al peer reviewed graph of the long term trends at Hay, Narrabri, Bourke and Alice Springs.
Thanks to Chris Gillham for finding the Deacon paper of 1952. [On another point, I'll have a response up to the new BOM "adjustments" page later. In short, their data still has many inexplicable errors like where maxima are lower than minima, and they are still not providing all the details we need to replicate their data and homogenization methods. - Jo]
But just have a look at this graph. Degrees Fahrenheit of course. State of the art, 1952.
These cooling trends cover “only” a couple of million square kilometers of Australia:
The location of Alice Springs, Bourke, Narrabri, and [...]
The average maximum temperatures [of SE Australia] during the last 35 years were between two and four degrees (F) lower than the average for the previous 35 years. — CSIRO 1953
Once upon a time — before the Great Politicization of Climate Science — CSIRO was able to analyze trends from 1880 to 1910. In 1953 CSIRO scientists were making a case that large parts of Australia had been hotter in the 1880s and around the turn of last century. They are referring specifically to summer maximums, and presumably the increase in rainfall over the same period played a large role in preventing hot days from becoming hotter. Minimum and mean trends may have been quite different, but these older maximum records are surely relevant when news headlines are drafted today about hot summers and heatwaves.
So what happened to the widespread lost hot decades?
I have a lot more to say on the warm and the work of these scientists. For the moment, the full archived news story is entertaining in its own right. Thanks to Chris Gillham for this link and to Jennifer Marohasy. Graphs tomorrow : – )
The Argus (Melbourne, Vic) Wednesday 18 March [...]
The list goes on, and there is more to come.
In Deniliquin NSW, the homogenisation has lifted both the maxima and minima trends — again converting cooling to warming.
Graham Lloyd continues to increase the pressure on the Australian Bureau of Meteorology. In answers to Lloyd the BOM could only defend their work with the extraordinary statement that while some trends at individual stations look anomalous, overall the results “showed a similar warming trend to that of other international climate organisations. ”
So they inadvertently admit that they expect Australian trends to look like trends in other parts of the world. Despite the fact that Australia is drier, flatter and surrounded on every edge by oceans, the Bureau would consider it a fail if our trends were different to others? We’re in the opposite hemisphere to many international climate organizations, which may or may not matter, but we’ll never find out if we are trying to fit our data to theirs. And El Nino’s and La Nina’s mean very different things to countries on opposite sides of the Pacific. We’re blurring the resolution from thousands of data-points. The raw data is blended not just on regional scales but thanks to [...]
Was January 3rd 1909 in Bourke one of Australia’s hottest days ever?
The historic records say “125F” — or 51.7C. The BOM say it was an observer error.
Bourke and neighboring stations in NSW and QLD Australia
Blair Trewin wrote a paper looking at the extreme highs in 1997. The Bourke record was made on a Sunday and in that particular year there are no records on other Sundays. On the other hand, I wonder what station observer would not notice a day that was 125F and head in to work to see exactly how high it was. The number 125F was handwritten in and underlined. You’d think observers would know it was a special figure, and pay attention.
The town of Bourke got a Stephenson Screen only a few months beforehand in August 1908, so it had good modern equipment. But Trewin thinks the record is an observer error, and points out that it was a lot warmer in Bourke than in other surrounding towns like Thargomindah, Walgett, and Coonable, and by about 6.9C degrees, which is an unusual gap. During the rest of the month Bourke was “not exceptionally hot compared to other stations”. Fair point. [...]
We’ve seen the remarkable change of the Rutherglen record as it got homogenized. This long running rural record that looks ideal apparently had “unrecorded” station moves found by thermometers miles away. Already we have found Bill Johnston who did some work at Rutherglen who confirmed that the station did not move. The mystery grows?
Since early 2012 Ken Stewart has been asking the BOM which neighbouring stations were used. Finally, after pressure from The Australian, the BOM has provided the 17 names, and Ken has graphed them.
Follow the chart below. Rutherglen temperatures start off in blue. The yellow line is the average of the 17 “neighbours” which are used to homogenize that blue line and transform it into the red one which somehow ends up being colder than its neighbours in 1952 and warmer than its neighbours in all the last 30 years.
See if you can figure it out?
Rutherglen starts off blue. Then the yellow line is used to homogenize that blue line into the red one.
Presumably the BOM technique would be a lot more complicated that what Ken has done, but clearly replicating that ACORN final trend is not going to be easy.
Hello Soviet style weather service? On January 3, 1909, an extremely hot 51.7C (125F) was recorded at Bourke. It’s possibly the hottest ever temperature recorded in a Stevenson Screen in Australia, but the BOM has removed it as a clerical error. There are legitimate questions about the accuracy of records done so long ago — standards were different. But there are very legitimate questions about the BOMs treatment of this historic data. ‘The BOM has also removed the 40 years of weather recorded before 1910, which includes some very hot times. Now we find out the handwritten original notes from 62 years of the mid 20th Century were supposed to be dumped in 1996 as well. Luckily, these historic documents were saved from the dustbin and quietly kept in private hands instead.
Bourke has one of the longest datasets in Australia — but the BOM, supposedly so concerned about the long term climate trends, appears to have little curiosity in the hot weather of the 1880′s and 1890′s (I talked about the amazing heatwave of 1896 here where hundreds died and people in Bourke escaped on special trains). If it had been a cool spell then, would the BOM feel [...]
Bronwen O’Shea, ABC
UPDATED: Correction. The interview was done by a fan of John Cook, not John Cook. Notes in the post and apologies. – Jo
Hm, curious event on the ABC today. Credit to Bronwen O’Shea, host of the ABC morning radio program for the Goulburn Murray, for asking both Jennifer Marohasy and the BOM to discuss the Rutherglen temperature adjustments. Good-o, I say – public debate and answers! (Note that link is just to their website, I have not found a copy of the interview or transcript).
But everything worked against the ABC. First the BOM chose not to even try to answer. (Hm?) Then not long after the interview started, the line suddenly went dead and Marohasy was abruptly cut off. She waited for the call back, but it never came. What bad luck eh? Even more unlucky – when the ABC tried to call her back they got a fan of John Cook on the phone instead*. Then, things got even worse for poor ABC listeners — because the fan of Cook mistakenly thought Rutherglen was different to the surrounding stations, but the BOM raw records say otherwise (see the graph below). UPDATED: Apologies to [...]
David Karoly knew he had to defend the BOM with regard to the hot questions about adjustments to Amberley, Bourke, and Rutherglen data. What he didn’t have were photos of historic equipment, maps of thermometer sites, or quotes from people who took observations. Instead he wielded the magic wand of “peer review” — whereupon questions asked in English are rendered invalid if they are printed in a newspaper instead of a trade-magazine.
Prof David Karoly, Climate Professional called people who ask for explanations poorly informed amateurs. In response, we Poorly Informed Climate Amateurs wonder what it takes to get Climate Professionals to inform us? Instead of hiding behind ‘peer review’, vague complex methods, and the glow of their academic aura, the professionals could act professional and explain exactly what they did to the data?
We discussed the mysterious transformation of Amberley and Rutherglen — where cooling trends became warming trends due to unrecorded site movements that were detected by thermometers hundreds of kilometers away. I also discussed how skeptical scientists have been asking for details for years but the BOM would not provide them. What we still don’t know is why thermometers in 1941 were recording temperatures nearly 2 degrees [...]
The hot questions for the Australian Bureau of Meteorology (BOM) mount up. Rutherglen was one of the temperature recording stations that was subject to large somewhat mysterious adjustments which turned a slight cooling trend into a strongly warming one. Yet the official notes showed that the site did not move and was a continuous record. On paper, Rutherglen appeared to be ideal — a rare long rural temperature record where measurements had come from the same place since 1913.
The original cooling trend of – 0.35C was transformed into a +1.73C warming after “homogenisation” by the BOM. To justify that the BOM claims that there may have been an unrecorded shift, and it was “consistent” with the old station starting further up the slope before it moved down to the hollow.
Today retired scientist Bill Johnston got in touch with Jennifer Marohasy, with me and with Graham Lloyd of The Australian to say that he worked at times at Rutherglen and the official thermometer had not moved. It was always placed where it is now at the bottom of the hollow. That information has already made it into print in The Australian.
The original thermometer records suggest a [...]
It’s the news you’ve been waiting years to hear! Finally we find out the exact details of why the BOM changed two of their best long term sites from cooling trends to warming trends. The massive inexplicable adjustments like these have been discussed on blogs for years. But it was only when Graham Lloyd advised the BOM he would be reporting on this that they finally found time to write three paragraphs on specific stations.
Who knew it would be so hard to get answers. We put in a Senate request for an audit of the BOM datasets in 2011. Ken Stewart, Geoff Sherrington, Des Moore, Bill Johnston, and Jennifer Marohasy have also separately been asking the BOM for details about adjustments on specific BOM sites. (I bet Warwick Hughes has too). The BOM has ignored or circumvented all these, refusing to explain why individual stations were adjusted in detail.
The two provocative articles Lloyd put together last week were Heat is on over weather bureau and Bureau of Meteorology ‘altering climate figures, which I covered here. This is the power of the press at its best. The absence of articles like these, is why I have said the media [...]
Congratulations to The Australian again for taking the hard road and reporting controversial, hot, documented problems, that few in the Australian media dare to investigate.
How accurate are our national climate datasets when some adjustments turn entire long stable records from cooling trends to warming ones (or visa versa)? Do the headlines of “hottest ever record” (reported to a tenth of a degree) mean much if thermometer data sometimes needs to be dramatically changed 60 years after being recorded?
One of the most extreme examples is a thermometer station in Amberley, Queensland where a cooling trend in minima of 1C per century has been homogenized and become a warming trend of 2.5C per century. This is a station at an airforce base that has no recorded move since 1941, nor had a change in instrumentation. It is a well-maintained site near a perimeter fence, yet the homogenisation process produces a remarkable transformation of the original records, and rather begs the question of how accurately we know Australian trends at all when the thermometers are seemingly so bad at recording the real temperature of an area. Ken Stewart was the first to notice this anomaly and many others when he compared the raw data to [...]
The mystery of Australian temperature adjustments
Ken Stewart has been checking the Australian BOM official ACORN minima data against the raw data. This week he highlights the six very strange cases of Brisbane Airport, Amberley RAAF, Dubbo, Rutherglen, Rabbit Flat, and Carnarvon. In all these places the adjustments change the trend by more than 2 whole degrees C. It’s a kind of hyper-homogenization.
Thermometers are supposed to be accurate to a tenth of a degree. Australian average trends are sometimes calculated to one hundredth of a degree. What then do we make of adjustments that change the trends by a whopping 2 degrees, and decades after the data came in? The only thing we know for sure about Australian temperatures is that we need an independent audit. Why is it left to volunteers to check? Surely the Greens want good data too?
Some of these stations are isolated outposts, so theoretically they are the heavyweights on Australian area-weighted averages. The map scales can be a bit deceptive. In outback Australia the nearest neighbours can all be 500 km away (300 miles). Some dots on the map are not so much a town as a motel and a gas station. [...]
Albany, Western Australia. Not near a desert. Not near the tropics. Hottest place in Australia?
Lucky, thanks to the BOM, that we have such high quality data to understand the Australian climate. Without it, we would never have found out that the hottest day ever recorded in Australia appears to be the 8th of February, 1933 in, wait for it… Albany, in the far cool south of Western Australia.
Chris Gillham emails:
“Guess where and when was the hottest day ever recorded in Australia? 50.7C at Oodnadatta on 2 Jan 1960? No way! Mardie at 50.5C on 19 Feb 1998? Get out of here! It was at Albany on 8 February 1933, that historic day when this normally chilly town on WA’s southern coast was razed with a temperature of 51.2C. Don’t believe me? You can’t question the accuracy of ACORN, a temperature network that shapes economic policy, and the screenshot from last night’s ACORN download for Albany max proves it …”
The all new marvellous ACORN dataset has been “expert peer reviewed”, it “employs the latest analysis techniques “ and it is “a complete re-analysis of the Australian homogenised temperature database”. Phew. The BOM lists their [...]
UPDATED, Ken has now finished the full tally of comparisons and the adjustments to minima increase trends by 47% . (Headline changed from 60% to 50% to reflect the shift.) See the new details of the last few stations at KensKingdom.
Billions of dollars, climate models, predictions, and hundreds of press releases depend on the BOM records of Australian temperatures. There were so many inconsistencies, inexplicable adjustments and errors that we put in a Senate request for the ANAO to audit the records. In response, to dodge the audit, the BOM dumped its HQ (“high quality”) dataset entirely, and established a new “best practise” ACORN dataset.
Independent volunteer auditors have been going through the ACORN records — thanks especially to Ken Stewart who is publishing his findings on his site as he works through the set. He’s analyzed 84 out of 104 sites, and finds that ACORN is just as bad as the HQ set. At Kenskingdom he shows that so far, the adjustments used to create the official Australian temperature record increase the warming trend by13% for maxima and a whopping 66% for minima. (Note the caveats in the conclusions below.)
The raw Australian data suggest the [...]
Bob Fernley Jones takes a close look at Australian temperature records, and finds that while the BoM can fish out records that are technically true, those “records” can also be paradoxically irrelevant and largely meaningless at the same time. Not so long back weren’t these same people telling us that only long term climate trends mattered, and that one hot or cold year, or bad storm was cherry picking and unscientific?
Dare I suggest the obsession with headline records is more a PR stunt than a scientific measure?
Its true, that 2013 was probably the warmest year in Australia averaged over the whole land mass and the whole year, at least since we started recording temperatures (a microsecond ago in geological time). But even so, for individual Australians it didn’t necessarily mean anything much at all. Nor has it got any scientific meaning; one hot summer over 5% of the surface of the world doesn’t tell us anything about cause and effect and CO2. But who would know that from reading a BoM release? But from BoM data we can tell that:
All seven states and territories of Australia have had significantly warmer summers in past years. (So, except for [...]
The CSIRO decided to leave out some information about the state of our climate in their State of the Climate Report CSIRO.
CSIRO published these “Fast Facts” in bold. I’m publishing the things they didn’t say, but could have, in points in between.
Fast Facts from the CSIRO and BOM “Australia’s climate has warmed by 0.9°C since 1910, and the frequency of extreme weather has changed, with more extreme heat and fewer cool extremes.” The CSIRO-BOM team could have said: Scientifically, extreme weather measures are lousy indicators. They’re noisy and not very meaningful. They are however useful for getting newspaper headlines. It depends on what your aim is… Australia’s had extreme hot days for as long as we’ve been measuring the temperature. Charles Sturt recorded 53C in 1828 which seems fairly extreme. Thomas Mitchell did it too in 1845 and are many others (see the map below, check Trove, ask the BOM — no don’t ask the BOM). The records prior to 1910 seem to have gone down the memory hole, but if the BOM and CSIRO were trying to give Australians a true sense of the state of our climate perhaps Australians might like to know that [...]
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