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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BOM homogenization errors are so big they can be seen from space

It’s just not cricket. And in so many ways.

Shame to let a perfectly good dataset go to waste… Australian data comes from some of the longest stations running in the Southern Hemisphere; it could be useful. Instead we get more evidence here that the BOM’s magical and secret homogenization adjustments can take poor data and spread false signals into better data. Homogenisation errors are already visible in a site-by-site analysis, but this shows the problems may be so big they affect averages across the whole of Australia, and we can detect them with satellites.

Tom Quirk continues comparing the satellite record of Australia with the BOM surface version. Previously, he (and for the record, Ken Stewart in 2015) showed that some discrepancies are due to the effect of heavy rain or drought. But now he looks further and finds that not-so-coincidentally, the largest gaps and most “inexplicable” differences occur in the mid nineteen-nineties, the same years the BoM shifted from using old large Stevenson screens to electronic thermometers. Around the same time, the large screens were often also swapped for much smaller ones too — like double jeopardy for data. Oddly, spookily, the BOM makes many adjustments to data [...]

Bourke: How 1km of land clearing can warm a million square miles

Yet again, we have to ask: does the Bureau of Meteorology care about Australia’s long term climate trend? Are they even trying?

Bourke could be one of the top ten most influential temperature sites in the world, mostly by virtue of being miles from anywhere, and used to homogenize a large slab of the land mass of Australia. Bill Johnston documents how changes to the site create most of the temperature trend.

The Bureau of Meteorology’s fancy magical and secret homogenization protocol does not detect changes that obviously affect the temperature (like the clearing in the photo below). But sometimes the BoM make “corrections” because of site changes that don’t appear to have mattered. Is it conveniently selective or just inept?

The BoM don’t even document major site changes a lot of the time. Even iconic sites that affect huge areas are badly managed. Someone got the tractor and plough and cleared the vegetation. As usual, a citizen scientist, a volunteer, documents it (along with a suite of other site changes).

In the last ten years land was cleared around the thermometer. This denuded area has a lower humidity, and higher volatility of temperatures.  The data from this thermometer [...]

Scandal: BoM ignores major site changes at iconic, historic, Sydney Observatory. Sloppy or deliberate?

Australia’s oldest and most iconic site has changed dramatically, but major site changes are not even being recorded.

The way the Bureau of Meteorology (BoM) treat this site says a lot about the unscientific, shoddy, biased standards it uses at sites everywhere. This was their headquarters. Experts walked past new walls, construction and highways, yet they didn’t record them? Beggars belief.

Just as Peter Ridd warns us that we can’t trust some marine and reef institutes,  Bill Johnston is the whistle-blower warning us about the Bureau of Met. There is no law  of science that says human institutes are infallible. When they run off the rails, how do we find out? Ridd issued a warning from the inside and ended up in the Federal Court. When people, like Bill write from the outside, the BoM waves the peer-review gatekeeper, and anonymous reviewers can easily shut that gate, and without any penalty.

The louvered thermometer house in front of the Observatory in 1864. (Courtesy of the State Library of NSW.)

Sydney Observatory is one of the longest running stations in the Southern Hemisphere, starting in 1859. It was Australia’s premier meteorology site and in the 1800′s it was known [...]

Another BOM scandal: Australian climate data is being destroyed as routine practice

Historic climate data is being destroyed

The Bureau have a budget of a million dollars a day, but seemingly can’t afford an extra memory stick to save historic scientific data.

In the mid 1990s thermometers changed right across Australia — new electronic sensors were installed nearly everywhere. Known as automatic weather sensors (AWS) these are quite different to the old “liquid in glass” type. The electronic ones can pick up very short bursts of heat –  so they can measure extremes of temperatures that the old mercury or liquid thermometers would not pick up, unless the spike of heat lasted for a few minutes. It is difficult (impossible) to believe that across the whole temperature range that these two different instruments would always behave in the exact same way. There could easily be an artificial warming trend generated by this change (see the step change in the graphs). The only way to compare the old and new types of thermometer is to run side by side comparisons in the field and at many sites. Which is exactly what the bureau were doing, but the data has never been put in an archive, or has been destroyed. It’s not easily available [...]

Scandal Part 3: Bureau of Meteorology homogenized-the-heck out of rural sites too

The  Australian Bureau of Meteorology have been struck by the most incredible bad luck. The fickle thermometers of Australia have been ruining climate records for 150 years, and the BOM have done a masterful job of recreating our “correct” climate trends, despite the data. Bob Fernley-Jones decided to help show the world how clever the BOM are. (Call them the Bureau of Magic).

Firstly there were the Horoscope-thermometers — which need adjustments that are different for each calendar month of the year – up in December, down in January, up in February… These thermometers flip on Jan 1 each year from reading nearly 1°C too warm all of December, to being more than 1°C too cold for all of January . Then come February 1, they flip again. Somehow the BOM managed to unravel this bizarre pattern (cue X-files music) and figure out exactly what anti-horoscope-adjustments to use (and they were different in every city). Modestly the BOM did not explain to the public how clever their adjustments were; despite their $300m budget, it took volunteer Bob Fernley-Jones to reverse out the Special Horoscope Cure, and find the square wave algorithm that repaired our damaged climate records. Lucky for the [...]

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 [...]

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 [...]

Two-thirds of Australias warming due to “adjustments” — according to 84 historic stations

1954 Yearbook Brisbane

Here’s an update to the digging through our historic records we discussed a month ago, we can now include nearly twice the stations and the difference between temperatures originally recorded 100 years ago and temperatures today are even smaller.

Chris Gillham has been working with CSIR documents and official Commonwealth Year Books. Last month he used the 1953 Year Book which contained 44 weather station averages for 1911-40 to compare with 2000-14 temperatures, but has since discovered that the 1954 Year Book provides an additional 40 stations with 1911-40 data. The average rise in mean temperatures across all 84 weather stations around Australia over the last 70 years of global warming is about 0.3C. This larger dataset suggests as much as two thirds of the current official trend in Australian warming was due to post hoc adjustments, not heat recorded by thermometers.

These historic temperatures were calculated by the best scientists of the day, using the best equipment of the era (the same Stevenson Screen we use now). Yet again, global warming appears to have a “man-made” contribution. Far more important than CO2 is man-made “pollution” called homogenisation.

When doubling the recorded trend makes “No difference”

Bear [...]

Explain this? Rutherglen homogenized with 17 stations including Hillston!

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.

The [...]

Threat of ANAO Audit means Australia’s BOM throws out temperature set, starts again, gets same results

Joanne Nova and Ken Stewart

A team of independent auditors, bloggers and scientists went through the the BOM “High Quality” (HQ) dataset and found significant errors, omissions and inexplicable adjustments. The team and Senator Cory Bernardi put in a Parliamentary request to get our Australian National Audit Office to reassess the BOM records. In response, the BOM, clearly afraid of getting audited, and still not providing all the data, code and explanations that were needed, decided to toss out the old so called High Quality (HQ) record, and start again. The old HQ increased the trends by 40% nationally, and 70% in the cities.

So goodbye “HQ”, hello “ACORN”. End result? Much the same.

That meant the ANAO could avoid an audit, since the BOM had changed data-sets, the point of auditing the old set was moot.

For me, this version is so much worse than the previous one. In the HQ data set the errors could have been inadvertent, but now we’ve pointed out the flaws, there can be no excuses for getting it wrong. Instead of fixing the flaws (and thanking the volunteers), it’s almost as if they’ve gone out of their way [...]