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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Vanishing hot days of December 1931 — and BOM monthly averages hotter than every single day that month

The hot desert border of Western and South Australia

Lance Pidgeon has drawn my attention to the mysteriously detailed weather maps of the Australian BOM, with their mass of contradictions. The intricate squiggles of air temperature profiles suggests an awesome array of data — especially remarkable in places like “Cook”, which is a railway station with a population of four. Eucla, the megopolis in the map, has a population of 368. The shared border in the map (right) is 674km long top to bottom.

Thankfully, after 80 years of modern technology, the weather at Eucla and in the Great Victorian Desert is much more bearable than anyone would have expected. The BOM ACORN data set works better than airconditioning. In places near Eucla, where old newspapers record 43C, the BOM tells us the highest maximum that month was “under 27C”. Far to the north of there, the highest maximum stayed under 36C, but the average for that same whole month was above 36C. Go figure. It’s a new kind of maths… [or maybe the miracle of reverse cycle a/c?]

There are a half million square kilometers in this map here and almost no [...]

A mess of adjustments in Australian capital cities — The inexplicable history of temperatures

Two out of three Australians live in our capital cities where the longest and best resourced temperature records would be found. These are the places where the weather reports matter to the most people on a daily basis — and where headlines about records and trends will be widely discussed.  But these are also the sites which have been affected by the growth of concrete and skyscrapers, and potentially have the largest urban heat island (UHI) effect, so might need the largest adjustments.

Bob Fernley-Jones has been going through the BOM records for six of Australia’s state capitals, looking at the original raw data (at least, as is recorded in the BOM’s climate data online, called CDO). Bob compares the new “corrected” dataset called ACORN for these locations — that’s the all new marvelous adjusted data. He finds many step changes that can’t be explained by known site moves or the UHI effect. Many step changes occur in either minima or maxima, but not in both at the same time, which is also odd. As we already know, the adjustments usually cool the past — especially the minima (see all the blue lines on graphs below [...]

Fewer heatwaves for 9 million Australians in Sydney, Darwin, Hobart, Melbourne –”thank CO2″!

Let’s play the Heatwaves PR game. If CO2 had an effect we’d see a significant increase in the rate of global warming over the decades since WWII, the models would work, and climate scientists would be able to predict our climate. Since none of that is true, those with a political agenda have to clutch at noisy but marketable extremes instead. Apparently even a half-true, noisy, non-causal link is good enough for post-modern scientists.

Heatwaves are perfect for generating scientific sounding fear, but not so useful for generating actual scientific knowledge. There are an infinity of ways to measure them. They can last 3 days – 160 days, and be cut off at any number from 35  – 40C, or at some percentile outlier. They can be measured one town at a time, or on a regional or state-wide level. The permutations are rich with headline scoring possibilities. And in the end, on a long warming trend that started 300 years ago, it is obvious, inevitable, and predictable that we should score more now. What’s surprising is how often we don’t.

On ABC radio before Easter, Dr Vertessy, Director and CEO of the Bureau of Meteorology, claimed that we are seeing [...]

Melbourne heat — BoM makes mystery corrections, but misses new skyscrapers. Incompetence?

More errors in ACORN – The Bureau of Met wonder-database corrects for mysterious “statisticals” but not for 15 story buildings built next to the thermometers. They correct a step change that doesn’t occur in minima, but don’t correct for one that does in maxima. Big site changes are marked in some datasets but not in others. And where is the correction for obvious urban heat island effects? Bear in mind, the size of the artificial steps and corrections is on a par with the warming supposedly due to carbon dioxide. Hmmm.

The BoM database needs to be independently and publicly replicated, all the way from their raw data to the final output down to several decimal places. Then we will all know what is going on. Let’s shine a light in. If it ain’t replicated, it ain’t science.

Melbourne has one of the longest temperature records in the Southern Hemisphere. Looking at the original records it appears Melbourne maximums have not changed much from 1855 – 1995. Then they suddenly jumped or stepped up.

Tom Quirk did some sleuthing, and figured out why that happened. But what he can’t figure out is why the Bureau missed this adjustment, yet makes [...]

Historic documents show 30-40%* of Australia’s warming trend is due to “adjustments”

UPDATE: *Chris has been over the entire dataset again, and makes a correction that adjustments account for 30-40% of the rise. A bit less than half. Headline updated. See his site for the newer stats. March 9, 2015

Adjustments that cool historic temperatures have almost doubled Australia’s rate of warming.

CSIR published “Meteorological Data” 1855 – 1931

 There was a time back in 1933 when the CSIRO was called CSIR and meteorologists figured that with 74 years of weather data on Australia, they really ought to publish a serious document collating all the monthly averages at hundreds of weather stations around Australia. Little did they know that years later, despite their best efforts, much of the same data would be forgotten and unused or would be adjusted, decades after the fact, and sometimes by as much as one or two degrees. Twenty years later The Commonwealth Bureau of Census and Statistics would publish an Official Year Book of Australia which included the mean temperature readings from 1911 to 1940 at 44 locations.

Chris Gillham has spent months poring over both these historic datasets, as well as the BoM’s Climate Data Online (CDO) which has the recent temperatures at these [...]

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 [...]