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 […]

Pitman says BOM don’t “fiddle” with data — it’s magical science by Elite Centres of Excellence

What is striking about Andy Pitman and Lisa Alexander’s response to the articles in The Australian, on The Conversation, is how intellectually weak it is, and how little content they have after we remove the logical fallacies. It’s argument from authority, circular reasoning, and strawmen. Hail the Gods (and don’t look over there)! They don’t question Jennifer Marohasy’s remarkable figures, they don’t even mention them at all, nor use the names “Rutherglen”, “Amberley” or “Bourke” –how revealing.

And these are the points at issue. Long cooling trends at supposedly excellent sites had been homogenized and transformed into warming trends. Rutherglen is the kind of station other stations dream to be: it has stayed in the same place according to the official documents, isn’t affected by the heat from urban growth either and is similar to its neighbors. Other stations might be adjusted to be more like it. Instead the BOM has a method that detected “unrecorded” site moves at Rutherglen by studying unnamed stations somewhere in the region. Awkwardly, someone who used to work there says the thermometer didn’t move. Hmm. Would a thinking person ask for more details and an explanation? Not if you are director of an ARC […]

ABC invites BOM and Marohasy to speak — BOM decline, Marohasy accepts, but is cut off?

Bronwen O’Shea, ABC

UPDATED: Correction. The interview was done by a fan of John Cook, not John Cook. Notes in the post and apologies. – Jo

Hm, curious event on the ABC today. Credit to Bronwen O’Shea, host of the ABC morning radio program for the Goulburn Murray, for asking both Jennifer Marohasy and the BOM to discuss the Rutherglen temperature adjustments. Good-o, I say — public debate and answers! (Note that link is just to their website, I have not found a copy of the interview or transcript).

But everything worked against the ABC. First the BOM chose not to even try to answer. (Hm?) Then not long after the interview started, the line suddenly went dead and Marohasy was abruptly cut off. She waited for the call back, but it never came. What bad luck eh? Even more unlucky — when the ABC tried to call her back they got a fan of John Cook on the phone instead*. Then, things got even worse for poor ABC listeners — because the fan of Cook mistakenly thought Rutherglen was different to the surrounding stations, but the BOM raw records say otherwise (see the graph below). UPDATED: Apologies to […]

Uninformed climate amateurs ask professionals to explain their data revision

David Karoly knew he had to defend the BOM with regard to the hot questions about adjustments to Amberley, Bourke, and Rutherglen data. What he didn’t have were photos of historic equipment, maps of thermometer sites, or quotes from people who took observations. Instead he wielded the magic wand of “peer review” — whereupon questions asked in English are rendered invalid if they are printed in a newspaper instead of a trade-magazine.

Prof David Karoly, Climate Professional called people who ask for explanations poorly informed amateurs. In response, we Poorly Informed Climate Amateurs wonder what it takes to get Climate Professionals to inform us? Instead of hiding behind ‘peer review’, vague complex methods, and the glow of their academic aura, the professionals could act professional and explain exactly what they did to the data?

We discussed the mysterious transformation of Amberley and Rutherglen — where cooling trends became warming trends due to unrecorded site movements that were detected by thermometers hundreds of kilometers away. I also discussed how skeptical scientists have been asking for details for years but the BOM would not provide them. What we still don’t know is why thermometers in 1941 were recording temperatures nearly 2 degrees […]

Australian BOM responds to Graham Lloyd, at The Australian

I respond to this letter in the post:

BOM finally explains! Cooling changed to warming trends because stations “might” have moved!

For the record, the entire response is below.

Media enquiry: Comparison of temperature charts

From: Graham Lloyd, The Australian

Date: 22 August 2014

Homogeneity adjustments are standard analyses carried out by agencies around the world.

FAQ: http://www.bom.gov.au/climate/change/acorn-sat/documents/ACORN-SAT-Fact-Sheet-WEB.pdf

As outlined in the Bureau’s previous correspondence, each temperature recording is the result of a range of choices — such as choice of instrument, choice of calibration, choice of instrument enclosure and choice of enclosure siting.

All of these elements are subject to change over a period of 100 years, and such non-climate-related changes need to be accounted for in the data. Put another way, one needs to determine whether changes recorded in unhomogenised temperature records are real or artificial — there can be no implicit assumption that such records are unaffected by changes in recording practice over time. This implicit assumption is often uncritically presented on internet blogs.

The international literature strongly concludes that data homogenisation is necessary for the creation of temporally consistent data […]

BOM finally explains! Cooling changed to warming trends because stations “might” have moved!

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 […]

The heat is on. Bureau of Meteorology ‘altering climate figures’ — The Australian

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 […]

Wow, look at those BOM adjustments – trends up by two degrees C!

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. […]

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 […]