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 [...]
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 [...]
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 [...]
Dennis Jensen, M.P. in the Australian Parliament, made a formal parliamentary request for an audit of the BOM and CSIRO data handling processes.
This is an excellent request, something Australia desperately needs. Good data on the climate.
Given how important our climate is, I’m sure Tim Flannery, The Climate Council, The Australian Conversation Foundation, and The Australian Greens will join us in demanding that the BOM and CSIRO datasets are independently audited. Naturally, all of us would want to ensure our climate data is of the highest quality possible and not subject to any kinds of confirmation bias, or inexplicable adjustments. Right? And maybe its even worse than we thought, so they will want to check, yes?
Let’s leave no stone unturned in making sure we understand the threats to the Australian environment, the impact on our farms and homes, and on our National Balance Sheet! How could any Green disagree?
Dennis Jensen talks about the response he got from the BOM and the questions he did not get answered:
” … the BOM state the temperature trend prior to 1910 is unreliable. But the IPCC use data on Australia going back to 1850. So [...]
Heatwaves have become a publicity tool. Far from there being a clear trend in Australian heatwaves, Geoff Sherrington shows that it’s also legitimate to claim heatwaves were worse 80 – 100 years ago in Adelaide and Melbourne and things are getting better. Those officials who cherrypick their claims might be technically correct, but it’s outrageously deceitful and unscientific at the same time.
Just how hard is it to get a record heatwave? It’s so easy that if it’s summer in Australia, it’s hard not to set a record. That’s because heatwaves come in so many flavors – there are seven capital cities which can all have 3 day, 4 day, 5 day or 6 day heatwaves. Then there are the heatwaves over 40C, or over 38 C, or over 35C… already that makes 84 flavours of wave. If a hot spell doesn’t break one type of wave, it could easily break another. Then there is the pre-heatwave, and there would be another 84 types of heatwaves that we haven’t had, but might get, you never know. You might think I’m kidding, but pre-heatwaves get headlines already:
“More Canberra heatwaves forecast”
“A heatwave could return to Canberra next month, [...]
What I found most interesting about this was the skill, dedication and length of meteorological data taken in the 1800′s. When our climate is “the most important moral challenge” why is it there is so little interest in our longest and oldest data?
Who knew that one of the most meticulous and detailed temperature records in the world from the 1800′s comes from Adelaide, largely thanks to Sir Charles Todd. The West Terrace site in Adelaide was one of the best in the world at the time, and provides accurate historic temperatures from “Australia’s first permanent weather bureau at Adelaide in 1856″. (Rainfall records even appear to go as far back as 1839.) Lance Pidgeon went delving into the National Archives and was surprised at what he found.
If we want to understand our climate the records from the 1800′s in Adelaide are surely worth attention?
The BOM usually shows graphs like this one below starting in 1911. You might think you are looking at the complete history of Adelaide temperatures and that smoothed temperature is rising inexorably, but the historic records remain unseen. While “hottest” ever records are proclaimed in [...]
How about some perspective on those alarming headlines:
Thanks to Steve Hunter
We are tying ourselves in knots over 150 year old records (or even less) when:
These are just short Australian records, not long global ones. Even in the 1800′s Australia recorded heatwaves of 50+ degrees. The world was similarly warm 1,000 years ago, definitely warmer 7,000 years ago, and a lot warmer 120,000 years ago. The world has been warmer for most of the last 500 million years. Satellites are more reliable, have better coverage, and don’t have dubious inexplicable adjustments. They show it was not a record angry summer, nor the hottest year we’ve had. [...]
Another round of government-funded PR went out a couple of weeks ago, across the obedient Pravda-media. It told us about another meaningless “record” that was probably not a record, and wouldn’t tell us whether man-made warming was the cause, even if it was. Not a single journalist had the wherewithal, nous or intellectual honesty to search the Internet looking for a different point of view. Though, in their defense, how could they have guessed that Prof David Karoly wouldn’t know about the UAH satellite program to measure temperatures? (It has only been running since 1979.)
This below, are the 12 month averages over Australia by satellite. Graphed at Kens Kingdom by Ken Stewart, with no doctorate in climatology and no government funds.
In the troposphere over Australia it was a hot year but not a record.
For the third time this year we’ve been hit with claims of a “hottest ever” record that doesn’t tell us anything about the climate, but does reveal a lot about the sick state of government funded science, corrupted, decrepit, and so far from being scientific it might as well be run by Greenpeace. If the government stopped funding climate science entirely, climate [...]
Lewis and Karoly 2013: climate change is “likely” to blame for the hottest angry summer.
Did your air-conditioner make Australia the hottest angry summer ever? Could be. If we apply mystery-black-box-techniques to data from a few sparse thermometers averaged over thousands of square kilometers we can find a “record”. If we compare that “record” to models that are known to be wrong, voila — then the coal fired power stations heated more than just your home, they heated the whole country.
On the other hand, if we use thousands of measurements from satellites that criss cross the nation day and night covering every corner of the land, we didn’t have a hot angry summer, we had a normal one. The Lewis and Karoly study is moot. If we caused a normal summer, is that so bad?
The not-angry-summer is visible with no statistical analysis.
According to UAH satellite measurements summer in early 2013 was not a record. Not even close.
Satellite records only go back to 1979, but to answer the question “was this the hottest ever summer” we only need records back as far as 2010.
The peer reviewed, comprehensive, Lewis and Karoly paper does not contain the [...]
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