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TWO weeks ago, in response to my queries the Australian Bureau of Meteorology acknowledged that it had put in place limits on the lowest temperature that an individual weather station could record.  So, when the automatic weather station which now operates in the town of Goulburn (not far from Canberra), recorded a measurement of minus 10.4 degree Celsius, the ‘quality control’ system in place ‘corrected’ this to minus 10.0 degree Celsius. None of this is denied.  When we protested, the Bureau emailed:

“The correct minimum temperature for Goulburn on 2 July, 2017 is -10.4 recorded at 6.30am at Goulburn Airport AWS… The Bureau’s quality control system, designed to filter out spurious low or high values was set at -10 minimum for Goulburn which is why the record automatically adjusted.

The error was picked up yesterday internally and quality control processes are being reviewed for those stations where temperatures below -10 are possible.

Further attempts at clarification have been met with stonewalling. Though after three days the Bureau did insert the correct measurement of -10.4 degree Celsius into the CDO dataset, where -10.0 had previously been showing.

I reported some of this in a note for The Spectator.

I had assumed that after this unfortunate incident the Bureau would remove the new absurd limits on how cold a temperature could actually be measured.   Indeed, the implications for the integrity of invaluable historical meteorological records are too horrible to contemplate.

I suffer, however, from a propensity to always check things.  So, when I thought temperatures might yet again dip below -10.0 degrees Celsius somewhere, I set my alarm for 5am, to get up early that morning to check (yes check) the values actually being recorded by the new automatic weather stations — particularly those scattered across the Australian Alps, given the weather-setup.  Then I would be in a position to subsequently check (yes check), to be sure any values measured below -10.0 were also taken forward into the official raw temperature dataset.

So, last Sunday morning (16 July) I got up at 5am and started checking the latest weather observations for the Snowy Mountains, including the locations of Perisher, Cooma and Thredbo.  At 5.30am the automatic weather station at the Thredbo Top Station (Number 071032) showed -10.4 degrees Celsius. I took a screenshot, and saved it on my computer.

This ‘latest weather observation’ pages automatically refreshes every 10 minutes. So, if this value was going to be erroneously reset to -10.0 — as the Bureau wrongly reset the -10.4 recorded at Goulburn two weeks earlier — I would want the screenshot as evidence.

I thought this would probably be the end of it.  Temperatures have actually got as low as -14.7 at Thredbo Top Station – with this value recorded on 28th July 1980.  Surely the Bureau would not reset the cold, but not exceptionally cold, value of -10.4 at Thredbo that I saw measured at 5.30 by that AWS on Sunday 16th July 2017.

Nevertheless, the next morning (Monday morning) I checked the ‘Daily Weather Observations’ sheet for the Thredbo Top Station at the Bureau website to be sure that the value of -10.4 had indeed been brought forward as the lowest value recorded so far this month at that weather station.

But alas! There was no minimum value recorded for Sunday 16th July.  And the sheet stated that -9.6 was the lowest/the coldest value so far recorded at Thredbo this July 2017.

This morning (Tuesday), I held out some hope that the correct value of -10.4 would nevertheless be recorded in the CDO database as the minimum for Thredbo on Sunday 16th 2017. But alas, they are again leaving a blank.

This is unforgiveable, surely someone is going to be sacked?  This either reflects an extraordinary incompetence, or a determination to prevent evidence of low temperatures.

While the Bureau just two weeks ago was adjusting values below -10.0 to -10.0 creating something of a bodge at Goulburn, they now appear to be leaving a blank — at least at Thredbo.

We know from the Climategate emails that the Manager of Climate Monitoring and Prediction at the Bureau, Dr David Jones, has little regard for numbers.  He wrote in an email on 7th September 2007 (ten years ago) that: “Truth be know, climate change here is now running so rampant that we don’t need meteorological data to see it.”

 

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OVER recent years I have documented the blatant remodelling of temperature measurements through the process of homogenisation. I have explained that it is the homogenised datasets that are used to report climate change by the Australian Bureau of Meteorology and the CSIRO.   I had assumed, however, that the raw data, kept in the CDO dataset, represented actual measurements.

Until late yesterday.

Late yesterday it was brought to my attention that the Bureau actually sets a strict lower limit on the extent to which a weather station can record a cold temperature.

So, when the weather station at Goulburn recorded -10.4 on Sunday morning – the Bureau’s ‘quality control system’, ‘designed to filter out spurious low or high values’ reset this value to -10.0.

To be clear, the actual measured value of -10.4 was ‘automatically adjusted’ so that it recorded as -10.0 in the key CDO dataset.

This is how the Bureau has attempted to explain away my concern that the -10.4 measurement as recorded in the Bureau’s observation sheet at 6.17am on Sunday morning, was not carried forward to the CDO dataset.

While it is reasonable to expect that the Bureau would have procedures in place to prevent the measurement of spurious temperatures, a simple frequency plot of minimum temperatures as recorded at Goulburn indicates that temperatures below -10.0 would be expected.

Which begs the question: Q1. When exactly was the limit of the daily minimum temperature for Goulburn set at -10.0 degree Celsius?

We have known for some time that through the process of homogenisation the Bureau practices historical revisionism – whereby adjustments are made to measurements so that regional and national trends better fit the theory of anthropogenic global warming – what I can now report is that procedures have also been put in place to limit the extent to which the actual measurements from individual weather station represent reality.

In particular at Goulburn, the weather station is set to adjust any value below -10.0, to -10.0.  Yet temperatures of -10.9 and -10.6 were recorded at Goulburn in 1994 – just a few years after the weather station was installed there.

So, a second question: Q2. How was it determined that temperatures at Goulburn should not exceed a minimum of -10.0?  

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Update 2.30 pm AEST on 6 July 2017

The following two charts from Jaco Vlok provide further insight into the Goulburn daily TMin data as recorded in the CDO dataset.

There is no unusual spike in the occurrence of -10.0.

The last few days have been very hot across eastern Australia. The mainstream media have been reporting ‘unprecedented’ conditions. This fits a popular narrative, but its inconsistent with the original historical record.

It was very hot in Australia in the late 1800s and the early years of the 1900s, particularly in outback Australia – at places like Bourke. Many of the extremely hot days were recorded using non-standard equipment, and so they are not recognised by Australia’s Bureau of Meteorology. Outrageously though, the Bureau has deleted from the raw digitised record the hottest day ever recorded in standard equipment at an official weather station. Ostensibly, because it was recorded on a Sunday – the day that the temperature-recorders normally had off in the days of manual temperature recordings.

No doubt the fellow who recorded temperatures from the thermometer in the Stevenson screen at the Bourke post office got up on the morning of Sunday 3rd January 1909, and decided he was going to work anyway. He was not going to miss what did turn out to be the hottest day of the century.

So, when I went to the trouble of getting access to the log book, now held by the National Archives of Australia, I could see that the fellow had not only written in 125 degree Fahrenheit (equivalent to 51.6 degree Celsius) – he had also underlined it!

I took a photograph of the entry, Exhibit 1.

Back then the person who recorded the temperatures each day, known as the ‘Observer’, was not the same person who compiled the ‘Abstract of Results’ at the end of the month. This supervisor (who used a red pen) sometimes made changes to temperatures as recorded by the Observer; and seems to have been initially confused as to the actual temperature on Saturday 2nd January 1909 at Bourke (originally changing it from 112 to 125).

The supervisor was clear in his summary though, writing in red that the highest temperature at Bourke for the month of January 1909 was 125 degree Fahrenheit recorded on 3rd January, as shown in Exhibit 2.

But if you go to the raw temperature data at the Australian Bureau of Meteorology’s website, there is no entry for this date, as shown in Exhibit 3.

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After looking at hundreds of temperature series from different locations across Australia, I’ve come to understand that only cities show the type of warming reported by the IPCC, and other such government-funded institutions. Much of this warming is due to what is known as the Urban Heat Island (UHI) effect: bitumen, tall-buildings, air-conditioners, and fewer and fewer trees, means that urban areas become hotter and hotter.

For example, in a recent study of temperature variability and change for south-east Australia it is evident that maximum temperatures in the cities of Melbourne and Hobart are increasing at a rate of about 0.8 degree Celsius per century; while the rate of increase at the nearby lighthouses is half of this.

While the trend of about 0.4 degree Celsius per century at the lighthouses – as shown in Chart 1 – is arguably an accurate record of temperature change, the Australian Bureau of Meteorology changes this. To be clear, the Bureau changes a perfectly good temperature series from Cape Otway lighthouse by remodeling it so that it has Melbourne’s temperature signal – all through the process of homogenisation.

Government agencies in the USA have done exactly the same thing to temperature records for Colorado. This is all explained in detail in this new video by Monte Naylor:
 
https://vimeo.com/196878603/b9ea716a74

The video runs for about 40 minutes, and is quite technical.

The conclusions from this study have been summarized by Monte as follows:

(1) The USHCN Fort Collins station temperature record was not recognized by NOAA as having the heat bias from expanding UHI which has been easily identified by other researchers.

(2) NOAA’s homogenization program adjusted the USHCN Boulder station temperature history in a fashion that does not match any of the four other nearby rural/suburban long-term temperature histories. Nor does the NOAA-homogenized Boulder temperature history resemble the average temperature trend found by this study.

(3) NOAA’s homogenization program adjusted the Boulder temperature history to resemble the UHI-contaminated temperature history of the Fort Collins station.

(4) The best estimate of the northern Colorado Front Range temperature trend is obtained by using the TOB-adjusted Group of 5 average which shows a warming temperature trend of 1.7 °F (0.95 °C) from 1900 to 2015. The NOAA temperature trend, about 4 °F over 115 years, is more than twice the best estimate of this study.

(5) About 70% of the warming shown in the Group of 5 average temperature trend occurred before 1932. Temperatures trends of recent decades do not show anomalous warming.  Distinct warm temperature events occurred in the 1930’s and 1950’s that were much warmer than those observed since the turn of the 21st century.

(6) The Northern Front Range Group of 5 average temperature trend does not increase in a fashion consistent with increasing atmospheric carbon dioxide.

Media reports yesterday claimed that 2016 was another record hot year. However, close scrutiny of all the temperature data from the state of Victoria paints quite a different picture. When all 289 temperature series from Victoria are simply combined, the hottest years are in the early part of the record. In particular, 1914 is very evidently the hottest year on record – see blue time series in Chart 1. This finding builds on a recently published book chapter focused on south-east Australia, and is part of a larger study working towards a realistic reconstruction of Australia’s temperature history.

Yesterday the Australian Bureau of Meteorology released its Annual Climate Statement, claiming 2016 to be the fourth-warmest year on record for Australia – and also an unusually wet year. Wet years are usually much cooler years, but because the overall trend in the ACORN-SAT* time series shows significant warming, even a wet year comes out as relatively hot.

Of course there is no one place in Australia where the average temperature can be measured; so the Bureau relies on a reconstruction to determine how hot 2016 was, relative to the historical record. Their method, however, is quite subjective in terms of choice of locations to include, the method used to remodel the individual temperature series before they are combined (this is refered to as homogenisation*), and the area weighting applied – with the weighting changing on a daily and monthly basis.

Late last year, I had a book chapter, co-authored with John Abbot and published by Elsevier*, which shows historical temperature trends for south-east Australia from 1887 to 2013 based on a more transparent system – that can be easily replicated. We choose the longest continuous series, used the same series to calculate every value, and applied an area weighting based on topography and landuse – and did not remodel individual temperature series. In the chapter we conclude that temperature trends for south-east Australia are best described as showing statistically significant cooling (yes cooling) of 1.5 degree Celsius from 1887 to 1949, followed by warming of nearly 2 degrees Celsius from 1950 to 2013. The warmest year in this reconstruction is 2007, followed very closely by 1914.

A colleague at the University of Tasmania, Jaco Vlok, has compared our south-east reconstruction with a reconstruction based on all 289 temperature series for Victoria – but only from 1910. The different methodologies used to generate these reconstructions, and also the official ACORN-SAT series for Victoria, which is the series used by the Bureau to calculate the official statistics for Australia, are detailed in Table 1.

There is a very high degree of synchrony between the reconstructions, though when all the raw data is simply combined – Vlok’s approach – the hottest years are all in the earlier part of the record: 1914 (hottest) followed by 1919, 1921, 1938, 1961 and then 2014.

Postscript: I have expanded on this analysis in an article just now published by Graham Young at OLO. Jennifer, Noosa, Monday 9th January, 2017.

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* ACORN-SAT stands for Australian Climate Australian Climate Observations Reference Network – Surface Air Temperature and is a dataset developed by the Bureau based on a subset of available temperature series, almost all homogenised, and then combined with an area weighting and used to report climate variability and change. The annual climate statement for 2016, based on this ACORN-SAT dataset, is here: http://media.bom.gov.au/releases/333/2016-a-year-of-extreme-weather-events/

* Homogenisation involves changes to measured temperature values ostensibly to correct for non-climatic variables. These changes to the observational data are quite different from quality assurance. For example, the need for homogenisation most often results from a ‘statistical test’ detecting a break point, these breakpoints often occur after a period of missing data. In response all values preceding the breakpoint are often reduced by a specific amount back to 1910. The amount by which the measured observational values are reduced is determined through the application of algorithms and calculated relative to what are referred to as ‘neighbouring’ stations, which may be Urban Heat Island (UHI) effected, and/or located many hundreds of kilometers from the target location.

* Marohasy, J. & Abbot, J. 2016. Southeast Australian Maximum Temperature Trends, 1887–2013: An Evidence-Based Reappraisal.  In: Evidence-Based Climate Science (Second Edition), Pages 83-99. http://dx.doi.org/10.1016/B978-0-12-804588-6.00005-7 You can read more about this series here: https://jennifermarohasy.com.dev.internet-thinking.com.au/2016/12/temperatures-trends-southeast-australia-1887-part/