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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Excuses? Coldest Summer day, Snow in Australia and suddenly BOM remembers how inadequate their equipment is…

Snow in December: Has Australia installed too many solar panels?

Climate Change brings summer snow to Australia

Coldest maximum summer temperature on record at Thredbo

Kate Doyle, ABC News

On Monday, the second day of summer, the temperature only reached -1 degrees Celsius at the Thredbo weather station, the coldest maximum temperature recorded anywhere in Australia during summer.

But really cold records don’t matter. For the first time in history, Blair Trewin, Bureau of Meteorology points out how minor these daily records are:

Blair Trewin, senior climatologist at the Bureau of Meteorology, confirmed that it was a summer as well as December record but pointed out there was more to it.

“In some ways it’s not quite as impressive as it looks,” Dr Trewin said.

This is indeed the only instance of him ever saying that.

“This is because before automatic weather stations were installed in the 1990s, manual observations at high mountain sites [like the top of Thredbo, Mount Hotham and Falls Creek] were very limited outside the ski season.”

Exactly. When will Blair Trewin tell Australians that hot records are not as impressive as they look because […]

Raw Data Bombshell: no change in Very Hot Days in Australia since World War I

What a bombshell. Despite the non-stop stories of unprecedented heat the original data at 60 of the oldest sites across Australia shows there are no more Very-Hot-Days now than there were early last century. That’s no trend in 40 degree days for 100 years. No change — that is, until the Bureau of Meteorology adjusts the data…

After we were shocked at the latest ACORN changes to our Very Hot Days data, I asked Chris Gillham if we could see the effect of Bureau of Meteorology changes to the original raw data – and he replied it would be too time-consuming writing the code to calculate 40C+ days among the millions of daily temperatures from 112 weather stations across Australia since 1910. Then he did it anyway.

Wow. In 2011, the BoM’s ACORN 1 adjustments wiped out some of the “very hot days” recorded at weather stations in the early 1900s. These were records that had stood for a whole century. Then, quietly six years later, the ACORN 2 readjustments turned the statistical air conditioner on again and cooled people from 100 years in the future.

It’s all especially miraculous given that even the old World War I data […]

Whopper part II: Look what the BoM did to the last three Februarys in Australia?!

The Bureau of Meteorology did what to February?

Wow, just wow. Look what the Bureau of Meteorology has covertly done to February? Something like one third of a degree has been added to the average Australian summer maximum anomalies over the past few years according to the “expert” data from the worlds-best-practise equipment.

In the BOM Whopper Part 1 we revealed that in the BOM’s latest round of unannounced adjustments there were big increases in the rate of Australian summer warming. It turns out a lot of the summer rise comes from changes to February. Mysteriously, there were large changes to the national average of the last three years. Let that sink in.

These changes were incomprehensible because while the averaged “whole nation” got warmer, there were no changes to the data in any of the 104 individual stations.

It’s all rather spooky… but what it isn’t, is scientific.

The two main points in Bob Fernley Jones’ work:

There are big increases to measurements recorded in the last three years? Why? Yet again, the adjustments are down in the early years, up in the latter years, and overall, the rate of warming, surprise, increases thanks to man-made adjustments. He […]

BOM Review admits skeptics were right, but say “trust us” it doesn’t matter

The BOM’s bad luck never seems to end. Of all the 695 stations in Australia, 693 worked perfectly, but Jen Marohasy and Lance Pidgeon happened to live near, or have a personal random connection to the only two stations that didn’t — Thredbo and Goulburn. Apparently these stations had been flawed (not fit for purpose) for 10 years and 14 years, but the BOM world-class experts hadn’t noticed. I expect they were just about to discover the flaws when (how inconsiderately) Lance and Jen announced the errors to the world and the BOM were forced to do this pointless 77 page report to stop people asking questions they couldn’t answer.

The nub of this fracas is that something called an MSI1 hardware card was installed in cold locations even though it would never report a temperature below minus 10.4C. Awkwardly this doesn’t explain why the 10.4C appeared in the live feed, then was automatically changed to -10C in the long term data sets which are used for climate analysis. Does the BOM think the dumb public don’t know the difference between -10 and -10.4? Implicitly — the BOM installed the wrong type of card, and also accidentally had an error […]

BOM Scandal: One second records in Australia — how “noise” creates history and a warming trend

Instrument errors, noise, may account for a quarter to one half of our national warming trend in the last century.

When the newspapers run a headline with Sydney hits, say, 44.4 degrees and that number gets engraved in history, who realizes that the extreme heat may have only lasted one second? You might think the maximum temperatures were above 44 for at least ten minutes, but the BOM will write it into the record books even if that heat lasts one second, and if the temperature a minute before was more than a whole degree cooler. We’re writing puffs of jet emissions, car exhaust, or random packets of hot (or cold) air into history books, and comparing these new records with old ones done in slow reacting liquid in glass thermometers. No wonder we are setting records!

In the last twenty years, electronic sensors have replaced most of the old fashioned thermometers. It’s for exactly this reason that we need the side-by-side comparison data that Bill Johnston asked for and which the BOM can’t supply because it is deleting the data – as a matter of routine practice.

Back in 1910, or even 1990, thermometers were not able to […]

Coldest Perth September recorded in 120 years of records (must be climate change)

In the last 120 years in Perth there has never been a September as cold as this one. We know that thanks to Chris Gillham, who has been tracking Western Australian weather in detail for years at WAClimate.net.

The headline in The West Australian today was Perth shivers through it’s coldest ever September. For some reason (I can’t think why) the extreme weather journalists did not mention climate change (has that ever happened on a hottest ever record story?). It’s so unusually cold here that wheat farmers, only weeks away from harvest*, are struggling with frost damage on crops. They are making snowmen from the frosts. It is supposed to be rapidly heating up but it is three degrees below normal.

Given the freak weather, Will Steffen immediately announced that “This is a prelude to a disturbing future. And it’s only going to get worse if we don’t address climate change.” No. Wait. Scratch that. That was South Australia, where one bad storm was caused by coal fired electrons. A record cold month is just weather.

Curiously, The Bureau of Meteorology(BOM) announced it was the coldest ever September for Perth since 1994 when records started at Mt Lawley, and […]

The BOM: Homogenizing the heck out of Australian temperature records

There are adjustments on top of adjustments. Homogenised records are being used to correct raw records. Some man-made adjustments can infect data for miles around…

Rutherglen is a long running station in central Victoria. There are no documented site moves, but the long raw trend of slow cooling was adjusted up to a warming trend. What was cooling of 0.35C per century became a 1.7C warming trend.

Jennifer Marohasy, and others, have spent months trying to get answers from the BOM explaining why these massive adjustments were made. Excuses flowed. In the latest round, the BOM claim the changes are necessary to make the Rutherglen record match the trends in the neighboring stations. What the BOM doesn’t say is that there was no warming in the neighbours either, not until after they were homogenized. The order in which stations are homogenized matters, which rather says something important about the arbitrary nature of the adjustments. Anomalous trends from far distant and poor locations can spread through waves of homogenization until better, longer stations succumb to political correctness and show the “correct” result. Small choices about which stations to to use first in the process can make a huge difference to the […]

Scandal: BoM thermometer records adjusted “by month” — mysterious square wave pattern discovered

There is some major messing with data going on.

What would you say if you knew that the official Perth thermometer was accurate at recording minimums for most of time in October in the eighties, but 0.7°C too warm all of December, and 1.2°C too cool in January? Bizarrely that same thermometer was back to being too warm in February! Try to imagine what situation could affect that thermometer, and require post hoc corrections of this “monthly” nature. Then imagine what could make that same pattern happen year after year. All those weather reports we listened to in Perth in 1984 were wrong (apparently). And this bizarre calendar of corrections is turning up all over Australia.

Bob Fernley-Jones has looked closely at all the adjustments done to achieve the wonderful homogenized ACORN data, as compared to the theoretically “raw” records listed in Climate Data Online (CDO) on the BOM website. He can’t know what the BOM did (since they won’t tell anyone), but he knows the outcome of their homogenization. He was shocked when he noticed a strange square-wave pattern repeating year after year; he was astonished that there were corrections calendar month by calendar month, up and down, switching […]

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 […]

Heatwaves in Australia: in many ways they are not hotter, longer or more common. Why won’t BOM and ABC say that too?

Heatwaves are a wonderful headline generator. That’s because the term sounds scary, yet the “wave” itself is undefined. A hundred different types of heatwave are theoretically possible, but they all sound the same in a headline. It means an activist team could pick and choose the particular one that scores a “record”. Heatwaves can be 3, 4, 5, 7 or 10 days. They can be measured by town, city, state or national data and they are can be above 35, 37, 40 degrees or… pick a number. A heatwave can be measured as days above some percentile of average. That means a few warm days in a cold town can be defined as a heatwave.

Geoff Sherrington, drawing no dollars from the taxpayer, takes a simple and obvious approach, and looks at 5 capital cities with the BOM raw and adjusted ACORN data. He considered 4, 5, and 6 day heatwaves to see if there was a trend. With 5 cites, 2 data types, 3 lengths of heatwave, Sherrington created 30 graphs. After testing all those different combinations of heatwaves, there were only three graphs out of 30 that showed an increasing trend. Over half of the heatwave graphs showed […]