JoNova

A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).


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The mysterious BOM disinterest in hot historic Australian Stevenson screen temperatures

When it comes to our rare high-quality historic records, and the real long term trends of Australian weather, the silence is striking. There are some excellent historical records of long term temperature data from the late 1800s in Australia, which lie underused and largely ignored by the BOM.

For the BOM, history almost appears to start in 1910, yet the modern type of Stevenson screen thermometer was installed across Australia starting as early as 1884 in Adelaide. Most stations in Queensland were converted as long ago as 1889 and in South Australia by 1892. Though states like NSW and Victoria were delayed until 1908.

Here’s a photo of the ones in Brisbane in 1890.

Brisbane was recording temperatures with modern Stevenson screens in 1890, as were some other stations, but the BOM often ignores these long records.

The BOM don’t often mention all their older temperature data. They argue that all the recordings then were not taken with standardized equipment. The BOM prefers to start long term graphs and trends from 1910 (except when they start in 1950 or 1970, or 1993).

The BOM was set up in 1908.  Before that there were Stevenson screens going in [...]

Marble Bar’s hottest day? Today might reach 49.1C again like it did 110 years ago

Will it be a hottest record at one of the hottest towns in the world today? The forecast for Marble Bar, Western Australia, is 49C. The record for Marble Bar stands at 49.2C or 120.5F recorded in 1905 and 1922. I guess if we give up our cars and airconditioners the temperatures in Marble Bar will go back to these ideal conditions?

Thermometer-spotting: the temperature has varied up and down.| The BOM page for Marble Bar: 48.3C at 2.54pm but the highest was 48.9C at 2:46 (8 minutes earlier?). | At 3:30pm the current temp is 48.4C but the highest as listed as 49C at 3:12pm. |  Now at 3:50pm the temperature has fallen to 47.9C and it looks like the peak was reached just short of the old record.

Overexcited journalists get 50C into headlines already

Sat Jan 14, 1905

At least one journalist is so excited he predicted it’s “highly likely” one of the towns in the area will hit the magic 49.5C which can be rounded up to 50C! (Seriously, Anthony Sharwood says that. Marvel at the power of odd versus even numbers and rounding conventions. It is not as though our modern media can [...]

Forgotten extreme heat, El Nino of 1878 — when miners would “knock off” at 44.4C!

What really happened in 1878?

The raw data at Nobby’s near Newcastle (graphed below) shows monster heat in 1878, 1879, and 1883 — far hotter than modern times. Its unlikely that it was recorded with modern equipment, so it’s hard to compare. Was it really hotter? We don’t know when the Stevenson screen was installed. I went hunting through our wonderful historic Trove archive of old newspaper records. It doesn’t help us make any accurate comparisons, or even tell us about annual averages, but there is a remarkable story of exceptional heat and dryness in January 1877 that few Australians know. Let’s revisit the times of forgotten people who lived when CO2 was perfect and the climate was ideal.

How hot were the 1800s in Australia? My favorite quote is about the miners near Braidwood (in the mountains between Canberra and the coast). It reached 108F but look at the cultural norms:

“Years ago in the valley the miners always ‘knocked off’ if the thermometer registered 112 degrees (44.4C) in the shade, but times and wages are changed now, and the poor men are willing, to work on days like last Friday 18.1.78″ (see the Freeman’s Journal link [...]

Satellites show 2014 was NOT the hottest ever spring (or winter or summer or autumn) in Australia.

The headlines are burning around the nation: 2014 was the hottest ever spring! Except it wasn’t. The UAH satellite coverage sees all of Australia, day and night, and are not affected by urban heat, airport tarmacs, “gaps in the stations”, or inexplicable adjustments.

When will the Bureau of Meteorology discover satellites? How many years will it take to train the ABC journalists to ask the BOM if satellite measurements agree or disagree with their highly adjusted, altered, deleted, and homogenised ground stations?

I used exactly no tax dollars to email John Christy of UAH, get the latest data, and graph it to show that in Australia 2014 was not the hottest spring, and not the hottest winter, summer or autumn either. Why can’t the BOM or the $1.1 billion ABC do that?

The obsession with cherry picked, unscientific and irrelevant single season records that are not even records shows how unscientific the Bureau of Met is. By its actions we see a diligent PR and marketing agency. If the BOM served the public, they would make sure the public knew that these records depend entirely on their choice of dataset and on their mysterious homogenization procedures. If the BOM were [...]

Excuses Excuses! Neville Nicholls and the Stevenson screens that didn’t exist or did and were “cracked”?

Neville Nicholls and Sophie Lewis are striking back at George Christensen, MP, who accused the BOM of “wiping” the official records of heat waves in 1896 and demanded an inquiry. For some reason, despite their world class work, Nicholls and Lewis still don’t seem keen on having an inquiry — so they go to some length to explain why it’s “false” to say it was hotter in 1896 than it was in 2013. Oddly though, to come to this conclusion they don’t use BOM work, because the BOM concluded “it would be very difficult to compare the 19th-century temperature data with modern observations.” Instead that difficult task was done by Berkley. Nichols calls it “brave”, but a “fact” at the same time.

In their long article, what they don’t explain is why they almost never mention any of the hundreds of ultra hot historic temperatures in their press releases and national news. George was “wrong”, and that’s a “fact” we’re told, but most of their article  on The Conversation explains why we don’t know what the temperature was in 1896. Try not to get confused.

That old data is dodgy see — I’ll paraphrase: Satellites agree with the BOM.  (Seriously, this [...]

Australian summer maximums “warmed” by 200%

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 [...]

The lost climate knowledge of Deacon 1952: hot dry summers from 1880-1910

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 [...]

1953 Headline: Melbourne’s weather is changing! Summers getting colder and wetter

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 : – )

– Jo

 

The Argus (Melbourne, Vic) Wednesday 18 March [...]

BOM homogenisation in Deniliquin creates discontinuities and changes trends

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 [...]

The mysterious lost hot Sunday in Bourke, did it really happen?

 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. [...]