Posts Tagged ‘Australia’

More Footprint Comparisons

June 18, 2019

In my previous post I showed different ways of comparing carbon dioxide emissions.

Here are some more, unashamedly with an Australian focus, in different formats.

As in my last post I use data from the Global Carbon Atlas for fossil fuel emissions for 2017 (the most recent data available), and Gross Domestic Product (GDP) data from the World Bank, also for 2017. GDP for each nation is calculated in current US dollars.

Percentages

Figure 1 shows cumulative percentages of 2017 fossil fuel emissions for all 202 countries with available data.

Fig. 1:  Cumulative CO2 emissions 2017 expressed as percentages

Globalco2 cum %

China, the USA, and India are the big hitters.  China produces 28.5% on its own.  Australia, in 16th place, produces 1.2% of global emissions, a bit behind Canada at 1.66%, and just ahead of the UK at 1.12%.  France and Italy are just over 1% each.  The remaining 183 countries each produce less than 1% – many much less.

Earth Hours

Earth Hour, where some people show how virtuous they are by switching off their lights for an hour in order to reduce emissions, might provide another way of comparing emissions.  I next compare emissions by units of “Earth Hours”.  One Australian Earth Hour is the amount of CO2 emissions reduced when:

Across Australia, all lights powered by fossil fuels; all stoves, fridges, air conditioners, and other appliances; all battery chargers; all street lights, traffic lights, and emergency lighting; all hospitals, schools, shopping centres, and telecommunications including computers; all mining operations; all transport- cars, trucks, trains, and aircraft; all farming operations; all water pumping; all manufacturing industry small and large, including steel and aluminium; all building and construction:  are shut down for one hour.

That is one Australian Earth Hour.

One Chinese Earth Hour is equal to 23.82 Australian Earth Hour units- Australia could run for 23 hours and 48 minutes on the equivalent amount of emissions. The value for America in Australian Earth Hours is 12 hours and 45 minutes; India, 6 hours; Russia, 4 hours; Japan, 2 hours 54 minutes. The value for the UK is 55 minutes and 53 seconds worth of Australian emissions output.

At the other end of the scale, El Salvador’s hourly emissions would last Australia for one minute.  Tuvalu’s total emissions are the equivalent of one tenth of one second of Australia’s emissions.

Efficiency

Here’s another idea.  Australia is the world’s 13th largest economy, and achieves this with emissions per dollar of GDP that put us in 105th place.  For all nations the average CO2 emissions per US dollar of GDP is 485 grams per dollar.  What if all countries were as efficient as Australia?  That is, they all had the same amount of emissions as Australia: 312 grams of CO2 per dollar of GDP.

Figure 2 shows what global emissions would look like if all nations were as efficient as Australia.

Fig. 2:  Global fossil fuel emissions currently and at Australia’s rate per dollar GDP

Global Oz efficiency

Or, to put it another way, Figure 3 shows the effect on the global economy for the same level of emissions.

Fig. 3:  Global GDP currently and at Australia’s emissions rate per dollar GDP

Global GDP Oz efficiency

That’s a potential increase of 37.7%.

Conclusion

Australia is punching above its weight in regard to efficiency of fossil fuel emissions per dollar of GDP.  Our carbon footprint is tiny compared with the big three- China, the USA, and India.  While there is always room for us to improve, if every country behaved as well as we do, the world would be a better place.

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Carbon Footprints in Perspective

June 16, 2019

According to a Lowy poll before our recent “climate change election”, apparently 89% of Australians were in favour of action on climate change.  They got it wrong of course, but there is still much gnashing of teeth over the size of our carbon footprint, especially in regard to our emissions per capita.   According to the University of Melbourne’s Climate Energy College, “Australia’s per-capita emissions remain the highest among its key trading partners”.

So how does Australia rate in the world of carbon emissions?

In this post I use data from the Global Carbon Atlas for fossil fuel emissions for 2017 (the most recent data available), and population, land area, and Gross Domestic Product (GDP) data from the World Bank, also for 2017. GDP for each nation is calculated in current US dollars.

Figure 1 shows 2017 fossil fuel emissions for all 202 countries with available data, in millions of tonnes of carbon dioxide.

Fig. 1:  Fossil fuel emissions 2017

CO2top5

In 2017 China was way in front with close to 10 billion tonnes of CO2 emitted, distantly followed by the USA, with India, Russia, and Japan well behind.  Australia was in 16th place, following Germany, Iran, Saudi Arabia, South Korea, Canada, Mexico, Indonesia, Brazil, South Africa, and Turkey.  At the other end of the scale the tiny Pacific nation of Tuvalu emitted only 13,000 tonnes of CO2.

In absolute terms our 413 million Tonnes of CO2 emissions are mediocre.  In the 20 years from 1998 to 2017, Australia’s carbon footprint increased by 78.4 million tonnes.  China’s increased by 6,573 million tonnes.  We’re not in the race, and it is blindingly obvious that however much we reduce our emissions we will have almost zero impact on the global total.

That is the reason that global warming enthusiasts in academia and the media promote the idea of per capita emissions- because we look worse that way.

Fig. 2:  2017 emissions per capita

CO2percap

It is certainly true that we emit larger amounts of CO2 per person compared with our major trading partners.  Fossil fuel is dirt cheap in oil rich nations, but in poor African countries each person emits less than a quarter of a Tonne of CO2 from fossil fuels per year.  There, firewood is the fuel of necessity, with severe consequences for health and the environment.  It is interesting that New Caledonia emits more per head than Australia.

Why does Australia hold this position?  The amount of wealth created by fossil fuel use is a measure of productivity and efficiency.  Figure 3 shows how countries rate in efficiency- how much CO2 is emitted for each US dollar in GDP.

Fig. 3:  2017 emissions per US $ GDP

CO2per$

Less is better.  Poorer countries that burn a lot of fossil fuel, and larger nations that do the same- including Russia, India, China, South Korea, and Indonesia- have less efficient economies than western nations including Canada, Australia, and the USA.  Small countries, especially those with nuclear and renewable energy, rich island nations, and poor African nations using very little fossil fuel make up the best.  Australia has a productive economy with historically cheap fossil fuels- but the most important reason for our relatively high emissions per capita is our size.

Figure 4, a comparison of carbon intensity, is an alternative way of comparing emissions, and because it takes into account the natural advantages of other advanced economies, demonstrates our carbon efficiency much better than population or GDP comparisons.

Fig. 4: 2017 emissions per land area

CO2persqkm

Australia, in 144th position, is followed only by countries with much smaller economies, and none of them apart from Iceland and Greenland are European.  All of our major trading partners, and many others, have much higher carbon intensity than Australia.  All Pacific Island nations, except for Papua New Guinea, Vanuatu, and the Solomon Islands, have higher carbon intensity as well.

Why?  Our economy is diffused across a wide brown land.  Even our cities are relatively thinly populated by world standards.  Production centres and markets are vast distances apart.  Russia, China, Canada, the USA, and Brazil are all larger in area than Australia.  Even so, our emissions are much less: Australia- 53.7 Tonnes per square kilometre; Brazil- 61.5; Canada- 63; Russia- 103.4; USA- 576; China- 1,048 Tonnes per square kilometre.

Don’t preach to us- Australia is a carbon sink by comparison with most other countries.

*****

As an appendix, here are three plots showing Australia’s relative position in the world.

Fig. 5:  2017 population

Poptop5

Fig. 6:  2017 GDP

GDPtop5

Fig. 7:  Land area

Areatop5

Australia is sixth in land area, 13th in GDP, and 53rd in population.  We are a large, under-populated, productive nation.  Naturally we have fossil fuel emissions to match.

ACORN-SAT 2.0: Nation-wide Summary

May 20, 2019

This is the eighth in a series of posts in which I directly compare the most recent version of Australia’s temperature record, ACORN-SAT 2, with that of the previous version, ACORN-SAT 1.  Results for the whole network are summarised below.

Introduction:

The Bureau of Meteorology has released its latest revision of the Australian temperature record back to 1910.  Previous versions of our historic temperatures included “High Quality”, which I revealed in 2010 to have major flaws, not least being the strong warming bias; and ACORN-SAT 1, released in March 2012, proudly touted as being “World’s Best Practice”, which I (along with others) found to have very many severe problems.  (If you like, check these posts, hereherehere, and here.  There are many others.)

Stung by the public and media criticism which this generated, the Bureau set up a supposedly independent Technical Advisory Forum, which met on one day per year for three years and basically rubber-stamped Acorn.  They did, however, make some recommendations, particularly about transparency.  In the light of this recommendation, this latest release without any publicity at all is perplexing.

Nearly all of Australia’s climate analysis and modelling is based on the previous version, Acorn 1, including monthly, seasonal, and annual means, extremes, and trends.  Sometime in the near future, this will be based on Acorn 2 data.

As this an upgrade to an existing dataset, we might expect there would be a few small tweaks of maybe a few tenths of a degree in some records and any changes to temperature trends would be fairly small.  Perhaps there might be some extra stations in remote areas to improve the density of the sparse network, perhaps some records starting earlier because of newly digitized data, hopefully a sensible fix for the dreadful situation of many daily minimum temperatures being higher than the maximum.

Not so.

No wonder the Bureau has released Acorn 2 so quietly- it is a confusing mess, and completely alters Acorn 1.  Trends are vastly different, some temperatures altered by more than 10 degrees Celsius, and new records established.

The basis for the new version is in the Research Report.  The Bureau has published a new station catalogue with more detailed information, the adjustment summary for each station, plus lists of comparative stations for adjustments and all comparison stations for each site, with explanations of adjustment terminology.  Well worth a look.

It is important to highlight this paragraph on the new ACORN-SAT home page:

The purpose of updating datasets like ACORN-SAT is principally to incorporate data that has been recorded since the last analysis was released, as well as historical paper records that have been recently digitised. ACORN-SAT version 2 also incorporates the findings and recommendations of the Technical Advisory Forum, applies the latest scientific research and understanding and, where applicable, introduces new methodologies. The overall aim of the update to ACORN-SAT is to provide improved estimates of historical changes in climate.

As well, in the ACORN-SAT FAQs, the Bureau says:

“… The important question is not which one (version) represents the absolute truth, but whether those estimates produce wildly different results, and whether the range of estimates provides a reasonable guide to what has actually occurred.”

Therefore, the Bureau has set their own criterion for whether Acorn 1 and Acorn 2 are at all useful and valuable.  To repeat:

“whether those estimates produce wildly different results, and whether the range of estimates provides a reasonable guide to what has actually occurred.”

Daily data were directly downloaded from the Bureau of Meteorology for maxima and minima for each of the 112 stations.

The Context

Figure 1:  Australian ACORN-SAT stations

Oz map all

There are 112 Acorn stations in the BOM database.  Differences between Acorn 1 and Acorn 2 are summarized in the following sections.

Largest temperature differences between Version 1 and Version 2

All temperatures are shown in degrees Celsius.

The five stations with the largest increases to daily maxima were:

Orbost (Victoria) 14.60
Wandering (W.A.) 10.90
Alice Springs  (N.T.) 10.10
Port Lincoln  (S.A.) 9.70
Scone  (N.S.W.) 8.30

The five stations with the largest decreases in daily maxima were:

Wandering  (W.A) -10.90
Cabramurra  (N.S.W.) -9.60
Esperance  (W.A.) -9.40
Alice Springs  (N.T.) -9.20
Wyalong  (N.S.W.) -8.60

Gunnedah (NSW) was the only station that had no changes made to the Version 1 values for maxima.

The five stations with the largest increases to daily minima were:

Merredin  (W.A.) 14.40
Butlers Gorge  (Tas.) 11.30
Alice Springs  (N.T.) 11.00
Scone  (N.S.W.) 9.60
Snowtown   (S.A.) 9.10

Horn Island (Qld) was the only station with no increases to daily minima.

The five stations with the largest decreases in daily minima were:

Wagga Wagga (N.S.W.) -13.40
Merredin  (W.A.) -12.60
Alice Springs  (N.T.) -11.50
Esperance  (W.A.) -10.80
Butlers Gorge  (Tas.) -9.70

Adjustments made to daily data were mostly of the order of +/- 1 or 2 ℃.  However the figures in the above tables show how enormous some adjustments were at many stations- including a range of 27 ℃ in adjustments to minima at Merredin!  That must surely rank as “wildly different results”.

New temperature extremes:

New records were set.

In Acorn 2 40 stations had increased record high maxima, 35 had their record highs decreased, and the remaining 37 were unchanged.  In minima, there were 36 stations whose lowest temperatures were increased, and 66 had new record lows. 10 were unchanged.

The old Australian record for highest maximum in Acorn Version 1 was (improbably) 51.2 ℃ at Albany in the far south of Western Australia.  In version 2, that has been reduced to 49.5 ℃.  The Version 2 highest maximum is now 51.1 ℃ at Oodnadatta in the South Australian desert.

The lowest temperature in Version 1 was -12.7 ℃ at Butlers Gorge in Tasmania.  That has been surpassed in version 2 by Inverell in northern inland New South Wales with -13 ℃.  (In raw data, the lowest at Inverell was -10.6 ℃ in July 1882.)

Here are the five stations with highest daily maximum temperatures.

Oodnadatta 51.10
Carnarvon 51.00
Forrest 50.10
Marble Bar 49.80
Port Hedland 49.7

Coldest minima:

Inverell -13.00
Butlers Gorge -12.70
Bathurst -11.50
Canberra -11.50
Cabramurra -10.70

Warmest minima stations are all coastal or islands:

Cape Moreton 5.10
Cairns 6.00
Weipa 9.10
Darwin 10.50
Horn Island 15.00

In Acorn version 2 there are some other peculiarities:  the “improved estimate” of climate change in Australia shows that Nhill, in western Victoria, has probably never had a frost, as its coldest morning has only been 2.7 ℃, the same as Sydney and Tennant Creek.   Alice Springs has the 69th hottest temperature at 45 ℃: far cooler than Albany, Eucla, Ceduna, or Port Lincoln far to the south.

Changes to temperature trends

With such enormous changes made to the daily data at so many stations, there have also been some major changes to temperature trends, both at individual stations and across the whole network.  (Trends are shown as degrees Celsius per 100 years).

Highest trends in maxima in Acorn 1

Cabramurra 4.75
Birdsville 3.21
Wyalong 3.00
Cunderdin 2.97
Cape Borda 2.90

Highest trends in maxima in Acorn 2

Wyalong 3.78
Cabramurra 3.66
Cunderdin 2.96
Birdsville 2.82
Ceduna 2.78

A trend of +4.75 ℃ per 100 years at Cabramurra high in the mountains is astounding- and the trend has been decreased by over one whole degree in Acorn 2.  The top four warming stations are the same in both datasets, but Cape Borda has been replaced by Ceduna in Acorn 2.  (Cape Borda went from 5th fastest warming to 15th; Ceduna went from 22nd to 5th.)

Highest trends in minima in Acorn 1

Rockhampton 3.10
Barcaldine 3.03
Laverton RAAF 3.03
Moree 3.01
Townsville 2.96

Highest trends in minima in Acorn 2

Rockhampton 3.41
Camooweal 3.27
Coffs Harbour 3.17
Horn Island 2.90
Laverton RAAF 2.81

Rockhampton maintains top position as fastest warming, and is warming even more in Acorn 2.  Laverton RAAF slips from third to fifth, while the other three places are completely changed.  Barcaldine slips from second fastest warming to 49th, replaced by Camooweal which rises from 41st!  Coffs Harbour has risen from 46th to third, but the gong for “most improved” must go to Horn Island, rising to +2.9 ℃ per 100 years in fourth place from +1.03 ℃ per 100 years in 72nd place,.    Those are definitelywildly different results”.

Greatest warming change in trends in maxima from Acorn 1 to Acorn 2

Eucla 1.50
Wittenoom 1.43
Giles 1.10
Ceduna 1.05
Port Macquarie 0.98

It seems that the improved methods used to create Acorn 2 has changed Eucla’s record to the extent thata reasonable guide to what has actually occurred” means an increase of +1.5 ℃ per 100 years in the rate of warming- an increase of 557%.

Greatest warming change in trends in minima from Acorn 1 to Acorn 2

Horn Island 1.87
Scone 1.86
Camooweal 1.71
Coffs Harbour 1.70
Tarcoola 1.51

The same applies to minima, with Horn Island’s warming trend increasing from +1.03 ℃ to +2.9 ℃ per 100 years.  Five stations had warming trends increase by more than 1.5 ℃, and 14 increased by more than 1.0 ℃ per 100 years.

Greatest cooling change in trends in maxima from Acorn 1 to Acorn 2

Victoria River Downs -1.07
Sale -1.07
Cabramurra -1.08
Moree -1.29
Rabbit Flat -1.64

The changes were not all in the same direction.  Rabbit Flat’s very patchy record takes the gong for the greatest cooling change in trend.  Rabbit Flat went from 24th fastest warming (+1.69 ℃ per 100 years) in Acorn 1 to 110th (third last) in Acorn 2- at +0.05 ℃ per 100 years.

Greatest cooling change in trends in minima from Acorn 1 to Acorn 2

Moree -0.89
Rabbit Flat -0.94
Halls Creek -1.32
Barcaldine -1.42
Giles -1.55

Again there were some big movers.  Rabbit Flat and Moree were again in the top five for most cooling change.  Giles had a similar fall from grace to record the greatest change: from 71st fastest warming (+1.03 ℃ per 100 years in Acorn 1) to second last place in Acorn 2 at -0.52 ℃, but Barcaldine went from second fastest warming to 49th, and Halls Creek from 58th fastest to 110th.

National Trends

In order to aggregate data into a national mean, all stations’ data were converted to anomalies calculated from their 1981 -2010 means.  There are 112 Acorn stations, but the Bureau insists that Urban Heat Island (UHI) warming makes eight of them (Townsville, Rockhampton, Sydney, Richmond RAAF (NSW), Melbourne, Laverton RAAF (Vic), Adelaide and Hobart) unsuitable for regional and national analysis.  The next plots show the change in trend from Acorn 1 to Acorn 2: first in maxima.

Figure 2: National mean of maxima at all stations

Acorn trends tmax all

Acorn 2 produces an increase in trend from +0.88 ℃ to + 0.99 ℃ per 100 years- an increase of 12.5%.

Figure 3: National mean of maxima at 104 stations, excluding those with UHI effect

 Acorn trends tmax nonUHI

Excluding eight UHI warmed stations produces virtually no difference from the trend of all 112 stations: +0.88 to +1.00 ℃.

Figure 2: National mean of minima at all stations

Acorn trends tmin all

In minima, the trend increases from +1.16 ℃ to +1.35 ℃ per 100 years- an increase of 16.4%.

Figure 3: National mean of minima at 104 stations, excluding those with UHI effect

 Acorn trends tmin nonUHI

Again, exclusion of UHI warming stations has a small effect, with the trend for non-UHI stations increasing from +1.15 ℃ in Acorn 1 to +1.37 ℃ per 100 years in Acorn 2.  That’s an increase of 19.1%.

Conclusion:

There are no additional stations, but additional digitised data at several stations has a large impact on annual trends.  As well, several Acorn 1 stations closed and their data merged with data from new sites in Acorn 2.

Large differences between Acorn 1 and Acorn 2 daily data of many degrees Celsius are found at many stations.  The largest changes ranged from -10.9 ℃ to +14.6 ℃ in maxima and -13.4 ℃ to +14.4 ℃ in minima.  Interestingly, no changes were made to Version 1 in Gunnedah maxima, and to Horn Island in minima.

New record maxima were established at 40 stations, with the remaining stations’ records being reduced or unchanged.  Australia’s “new” record high temperature is 51.1 ℃ at Oodnadatta.  The largest increase was of +2.5 ℃ at Carnarvon.  Our “new” record low temperature is -13 ℃ at Inverell.  The largest decrease in record low is -2.7 ℃ at Alice Springs.

Trends at individual stations in maxima and minima have often seen spectacular changes: changes in trend over Acorn 1 of from -1.64 ℃ to +1.87 ℃ per 100 years.  These changes resulted in very large changes in relative placing of fastest warming or cooling.  Eucla’s trend in maxima was increased more than six and a half times: 557%.  Broome’s minima trend increased more than five and a half times: 461%.

The size of the adjustments only seven years after the “world’s best practice” dataset was launched, is incredible.  The explanation that Acorn Version 2 “applies the latest scientific research and understanding and, where applicable, introduces new methodologies”, is beyond belief, as most datasets are vastly different from Acorn Version 1.  This is not incremental improvement.

In the ACORN-SAT FAQs, in the answer to:

“Why should the adjustments change, weren’t they correct the first time?”

the Bureau says:

“… The important question is not which one (version) represents the absolute truth, but whether those estimates produce wildly different results, and whether the range of estimates provides a reasonable guide to what has actually occurred.”

By their own words they have condemned themselves- “wildly different results” is exactly what has been produced.  Adjustments made in Version 1 were apparently made in error as they have been “corrected” by adjustments in version 2.  Will these adjustments be in error and corrected in version 3?

The Bureau officers responsible for Acorn version 2 appear to be blissfully unaware that they have made adjustments of up to 14.6 ℃ to temperatures in the dataset they proudly claimed to be world’s best practice just seven years ago.

Acorn 2, as the best estimate of Australia’s temperature record, is a failure.

ACORN-SAT 2.0: New South Wales- What a mess

April 10, 2019

This is the seventh in a series of posts in which I directly compare the most recent version of Australia’s temperature record, ACORN-SAT 2, with that of the previous version, ACORN-SAT 1.  Daily data are directly downloaded from the Bureau of Meteorology. I do not analyse against raw data (available at Climate Data Online), except for particular examples, as I am interested in how different Acorn 2 is from Acorn 1.  The basis for the new version is in the Research Report.  The Bureau has published a new station catalogue with more detailed information, the adjustment summary for each station, plus lists of comparative stations for adjustments and all comparison stations for each site, with explanations of adjustment terminology.  Well worth a look.

See my previous posts for Western Australia, the Northern TerritoryQueensland,  South Australia, Tasmania, and Victoria for a general introduction.  It is important to highlight this paragraph on the new ACORN-SAT home page:

The purpose of updating datasets like ACORN-SAT is principally to incorporate data that has been recorded since the last analysis was released, as well as historical paper records that have been recently digitised. ACORN-SAT version 2 also incorporates the findings and recommendations of the Technical Advisory Forum, applies the latest scientific research and understanding and, where applicable, introduces new methodologies. The overall aim of the update to ACORN-SAT is to provide improved estimates of historical changes in climate.

As well, in the ACORN-SAT FAQs, the Bureau says:

“… The important question is not which one (version) represents the absolute truth, but whether those estimates produce wildly different results, and whether the range of estimates provides a reasonable guide to what has actually occurred.”

Therefore, the Bureau has set their own criterion for whether Acorn 1 and Acorn 2 are at all useful and valuable.  To repeat:

“whether those estimates produce wildly different results, and whether the range of estimates provides a reasonable guide to what has actually occurred.”

The Context – New South Wales

Figure 1 is a map of Australia showing all of the Bureau’s ACORN-SAT climate monitoring stations.  New South Wales is the oldest and most populous state with climates varying from semi-desert to montaine.

Figure 1:  Australian ACORN-SAT stations

NSW map all

There are 25 Acorn stations in the NSW BOM database.  Differences between Acorn 1 and Acorn 2 are summarized in the following sections.

Additional data

An extra 27 years of data have been digitised for Canberra, and 45 years for Moree, which has had an enormous effect on annual temperature trends (see below).  Some locations had changes to new sites, with Acorn 1 data merged to Acorn 2 data, including Tibooburra and Wilcannia.

Largest temperature differences

In maxima, changes to Acorn 1 daily data ranged from +8.3 ℃ at Scone in 1996 to -9.6 ℃ at Cabramurra in 1998 applied to individual daily figures.

Remarkably, there were NO changes from Acorn 1 to Acorn 2 at Gunnedah.

Figure 2:  Daily changes in maxima from Acorn 1 to Acorn 2 at Cabramurra

Cabramurra max adj

Minima adjustments ranged from -13.4 ℃ at Wagga Wagga in 1946 to +9.6 ℃ at Scone in 1996 on individual days but with many days adjusted by -2 ℃ or greater.

Figure 3:  Daily changes in minima from Acorn 1 to Acorn 2 at Wagga Wagga:

Wagga min diffs

(Remember, these are adjustments to Acorn 1, which was supposed to be “world’s best practice” seven years ago.  How did the Bureau get it so wrong the first time?  Has world’s best practice changed so much in seven years?)

Record temperatures

New record maxima were established at nine stations, with the highest at Bourke (48.9 ℃) while other stations’ record highs were unchanged or reduced.  There were two notable changes.  Figure 4 shows maxima at Sydney in 1939, where the record was increased by 2.5 ℃ to 47.9 ℃.

Figure 4:  Three versions of maxima at Sydney in 1939

Sydney record max

(The temperature was below 20 ℃ on 16th and 17th.)

Figure 5 shows Port Macquarie, whose record maximum was reduced by -4.1 ℃ from 48.1 ℃ to 44 ℃ in 1944.

Figure 5:  Two versions of maxima at Port Macquarie in 1944

PtMcquarie record max

There is NO daily raw data for any Port Macquarie site from 1921 to 1956 at Climate Data Online, so there is no way of replicating these adjustments.

Such “wildly different results” are beyond rational explanation.

New record low temperatures were established at 15 stations, and a new record low for Acorn stations was set, not at Cabramurra in the Snowy Mountains, but at Inverell in the north: -13 ℃.  Canberra’s minimum was reduced by 2.9 ℃ to -11.5 ℃.

Figure 6:  Three versions of minima at Inverell

Inverell record min

Raw minimum of -10 ℃ is cold enough.  Acorn version 1 had cooled this further by 1.4 ℃, but version 2 cools version 1 by another 1.6 ℃, making it three degrees cooler than the raw figure.  Strange things happen in the past!

Quality Control: especially minimum temperatures higher than maximum.

In Acorn 1, 15 out of the 25 stations had at least one example of minimum higher than maximum- including 12 times at Bourke and Sydney, 15 at Tibooburra, and 212 times at Cabramurra.  The worst example was minimum 2.2 ℃ above maximum in October 1913 at Tibooburra.  Blair Trewin claims he has “fixed” this problem (which he concedes was “physically unrealistic”) by adjusting temperatures in Acorn 2 so that the maximum and minimum are the same, so that DTR for the day is zero.  In his words:

A procedure was therefore adopted under which, if a day had a negative diurnal range in the adjusted data, the maximum and minimum temperatures were each corrected to the mean of the original adjusted maximum and adjusted minimum, creating no change in the daily mean.

That is almost how he “corrected” the worst NSW example in Acorn 1 (minimum 2.2 ℃ above maximum at Tibooburra).  Here is a plot of the raw data and changes made by Acorn 1 and Acorn 2 at Tibooburra in 1913.

Figure 7:  Tibooburra temperatures October-November 1913

Tibooburra DTR 1913

Acorn 1 maxima (orange line) were reduced too far below Raw (brown). Acorn 1 minima (grey) were too far above raw minima (light blue).  Result: garbage. Acorn 2 has changed maxima (dark red) back to 0.1 ℃ below the raw value, and reduced minima (dark blue) from 17 ℃ to 16 ℃.  This is not the “mean of the original adjusted maximum and adjusted minimum”- but at least the DTR is not negative.

The problem was caused by far too large adjustments to both maxima and minima, and was fixed by more arbitrary adjustments.

Not all Acorn 2 adjustments resulted in an increase in warming- in several, the warming trend was reduced.  For example, Figure 8 shows annual temperature trends at Sydney.

Figure 8:  Maxima Trends in Sydney 1910-2017

Sydney max ann trends

The warming rate of +1 ℃ per 100 years in Acorn 1 has been reduced to +0.79 ℃ in Acorn 2.

However, at Coffs Harbour the warming trend in minima was more than doubled, from +1.47 ℃ to +3.17 ℃ per 100 years.

Figure 9:  Minima trends at Coffs Harbour 1952-2017

CoffsHbr min ann trends

Figure 10 shows the effect of including an extra 27 years of data on annual trends at Canberra, with Acorn 1 adjusted downwards from 2011.

Figure 10:  Trends in Canberra minima 1914-2017

Canberra min ann trends

Acorn 1 starts in 1940.  Canberra’s warming trend has been increased from +1.48 ℃ to +2.18 ℃ per 100 years.

Conclusion:

There are no additional stations, but additional digitised data at several stations has a large impact on annual trends.  As well, several Acorn 1 stations closed and their data merged with data from new sites in Acorn 2.

Large differences between Acorn 1 and Acorn 2 daily data of many degrees Celsius are found at several stations.  Interestingly, no changes were made to Version 1 in Gunnedah maxima, and only a few in minima.

New record maxima were established at nine stations, with the remaining stations’ records being reduced or unchanged.  The largest increase was of +2.5 ℃ at Sydney, and the largest decrease was at Port Macquarie where the record high was reduced by -4.1 ℃.

The issue of instances of minima being higher than maxima caused by too vigorous adjustments at 15 stations (including 12 times at Bourke and Sydney, 15 at Tibooburra, and 212 times at Cabramurra) has been “fixed”- only seven years after the problem was pointed out.

Not all Acorn 2 adjustments resulted in an increase in warming- in several, the warming trend was reduced.  However, excessive adjustments have resulted in Coffs Harbour’s Acorn 1 minima trend of +1.47 ℃ per 100 years being more than doubled to +3.17 ℃ in Acorn 2.

The size of the adjustments only seven years after the “world’s best practice” dataset was launched, is incredible, and demands explanation.  The explanation that Acorn Version 2 “applies the latest scientific research and understanding and, where applicable, introduces new methodologies”, is beyond belief, as most datasets so far examined are vastly different from Acorn Version 1.  This is not incremental improvement.

In the ACORN-SAT FAQs, in the answer to:

“Why should the adjustments change, weren’t they correct the first time?”

the Bureau says:

“… The important question is not which one (version) represents the absolute truth, but whether those estimates produce wildly different results, and whether the range of estimates provides a reasonable guide to what has actually occurred.”

By their own words they have condemned themselves- “wildly different results” is exactly what has been produced.  Adjustments made in Version 1 were apparently made in error as they have been “corrected” by adjustments in version 2.  Will these adjustments be in error and corrected in version 3?

The Bureau officers responsible for Acorn version 2 appear to be blissfully unaware that they have made adjustments of up to 13.4 ℃ to temperatures in the dataset they proudly claimed to be world’s best practice just seven years ago.

What a mess.

I will next show a summary of Version 2 changes across the whole network, and then look at annual trends at all stations.

ACORN-SAT 2.0: Victoria- A comedy of errors

April 5, 2019

This is the sixth in a series of posts in which I directly compare the most recent version of Australia’s temperature record, ACORN-SAT 2, with that of the previous version, ACORN-SAT 1.  Daily data are directly downloaded from the Bureau of Meteorology. I do not analyse against raw data (available at Climate Data Online), except for particular examples, as I am interested in how different Acorn 2 is from Acorn 1.  The basis for the new version is in the Research Report.  The Bureau has published a new station catalogue with more detailed information, the adjustment summary for each station, plus lists of comparative stations for adjustments and all comparison stations for each site, with explanations of adjustment terminology.  Well worth a look.

See my previous posts for Western Australia, the Northern TerritoryQueensland,  South Australia, and Tasmania for a general introduction.  It is important to highlight this paragraph on the new ACORN-SAT home page:

The purpose of updating datasets like ACORN-SAT is principally to incorporate data that has been recorded since the last analysis was released, as well as historical paper records that have been recently digitised. ACORN-SAT version 2 also incorporates the findings and recommendations of the Technical Advisory Forum, applies the latest scientific research and understanding and, where applicable, introduces new methodologies. The overall aim of the update to ACORN-SAT is to provide improved estimates of historical changes in climate.

As well, in the ACORN-SAT FAQs, the Bureau says:

“… The important question is not which one (version) represents the absolute truth, but whether those estimates produce wildly different results, and whether the range of estimates provides a reasonable guide to what has actually occurred.”

Therefore, the Bureau has set their own criterion for whether Acorn 1 and Acorn 2 are at all useful and valuable.  To repeat:

“whether those estimates produce wildly different results, and whether the range of estimates provides a reasonable guide to what has actually occurred.”

The Context – Victoria

Figure 1 is a map of Australia showing all of the Bureau’s ACORN-SAT climate monitoring stations.  Victoria is a small state with climates varying from semi-desert to montaine.

Figure 1:  Australian ACORN-SAT stations

Vic map

There are eleven Acorn stations in the Victorian BOM database.  Differences between Acorn 1 and Acorn 2 are summarized in the following sections.

Additional data

An extra 36 years of data have been digitised for Sale, which has had an enormous effect on annual temperature trends (see below).  Melbourne Regional Office observations ceased on 6 January 2015, but Acorn 2 continues the series with Olympic Park, with an overlap of 19 months.

Largest temperature differences

In maxima, changes to Acorn 1 daily data ranged from +14.6 ℃ at Orbost in 2012 to -4.4 ℃ at Sale in 2013 applied to individual daily figures.

Figure 2:  Daily changes in maxima from Acorn 1 to Acorn 2 at Orbost

Orbost max adj

Minima adjustments ranged from -7.4 ℃ at Orbost to +6.2 ℃ at Rutherglen in 1926 on individual days but with many days adjusted by -2℃ or greater.   Most changes were small but numerous, for example at Rutherglen where the changes to Acorn 1 ranged between -1 ℃ and +2 ℃ for many years.

Figure 3:  Daily changes in minima from Acorn 1 to Acorn 2 at Rutherglen:

Rutherglen min diffs

(Remember, these are adjustments to Acorn 1, which was supposed to be “world’s best practice” seven years ago.  How did the Bureau get it so wrong the first time?  Has world’s best practice changed so much in seven years?)

Record temperatures

New record maxima were established at Cape Otway, Gabo Island, and Mildura, while other stations’ record highs were unchanged or reduced.

Figure 4:  Three versions of maxima at Mildura in 1960

Mildura record max

That eclipses Mildura’s record in raw temperatures of 46.9 ℃.

New record low temperatures were established at Cape Otway, Laverton, Melbourne R.O., Nhill, Rutherglen, and Wilson’s Promontory.  Melbourne’s minima was reduced by 1.1 ℃ to -1.5 ℃.

Figure 5:  Three versions of minima at Melbourne Regional Office

Melbourne record min

Acorn version 1 had warmed the minima by 0.5 ℃, but version 2 cools version 1 by 1.2 ℃, making it 0.7 ℃ cooler than the raw figure.  Strange things happen in the past!

Quality Control: especially minimum temperatures higher than maximum.

In Acorn 1, eight out of the eleven stations had at least one example of minimum higher than maximum- including 48 times at Orbost, 63 at Cape Otway, and 79 times at Wilson’s Promontory.  The worst example was minimum 1.8 ℃ above maximum in February 1946 at Orbost.  Blair Trewin claims he has “fixed” this problem (which he concedes was “physically unrealistic”) by adjusting temperatures in Acorn 2 so that the maximum and minimum are the same, so that DTR for the day is zero.  In his words:

A procedure was therefore adopted under which, if a day had a negative diurnal range in the adjusted data, the maximum and minimum temperatures were each corrected to the mean of the original adjusted maximum and adjusted minimum, creating no change in the daily mean.

That is not how he “corrected” the worst Victoria example in Acorn 1 (minimum 1.8 ℃ above maximum at Orbost).  Here is a plot of the raw data and changes made by Acorn 1 and Acorn 2 at Orbost in 1946.

Figure 6:  Orbost temperatures January – February 1946

Orbost DTR

Acorn 1 maxima (orange line) were reduced below Raw (brown). Acorn 1 minima (grey) were too far above raw minima (light blue).  Result: garbage. Acorn 2 has changed maxima (dark red) back to approximately raw values, and reduced minima (dark blue) markedly.  This is not the “mean of the original adjusted maximum and adjusted minimum”.

The problem was caused by far too large adjustments to both maxima and minima, and was fixed by reducing the minimum, and raising the maximum, on all days to almost the same as the raw figures.

Figure 7 shows the effect Acorn version 2 tinkering adjustments have on annual temperature trends at Nhill.

Figure 7:  Trends in Nhill minima 1944-2017

Nhill min ann trends

Acorn 1 had this series cooling very slightly at -0.13 ℃ per 100 years but Acorn 2 has reversed the Acorn 1 trend to +0.67 ℃ per 100 years.  (This is restored to about 0.13 ℃ above what the “raw” trend showed.)

Figure 8 shows the effect of including an extra 36 years of data on annual trends at Sale.

Figure 8:  Trends in Sale maxima 1910-2017

Sale max ann trends

The arrow shows where Acorn 1 starts in 1946.

Conclusion:

There are no additional stations, but an extra 36 years of data at Sale has a large impact on annual trends.  Melbourne Regional Office is now amalgamated with Olympic Park, despite having only 19 months of overlap.

Large differences between Acorn 1 and Acorn 2 daily data of several degrees Celsius are found at Orbost, Sale, and Rutherglen.

New record maxima were established at Cape Otway, Gabo Island, and Mildura. New record low temperatures were established Cape Otway, Laverton, Melbourne R.O., Nhill, Rutherglen, and Wilson’s Promontory.

The issue of instances of minima being higher than maxima caused by too vigorous adjustments at eight stations (including 48 instances at Orbost, 63 at Cape Otway, and 79 at Wilson’s Promontory) has been “fixed”- only seven years after the problem was pointed out.

Excessive adjustments have resulted in Nhill’s Acorn 1 minima trend of -0.13℃ per 100 years being changed to +0.67 ℃ in Acorn 2.

The size of the adjustments only seven years after the “world’s best practice” dataset was launched, is incredible, and demands explanation.  The explanation that Acorn Version 2 “applies the latest scientific research and understanding and, where applicable, introduces new methodologies”, is beyond belief, as nearly every dataset so far examined is vastly different from Acorn Version 1.  This is not incremental improvement.

In the ACORN-SAT FAQs, in the answer to:

“Why should the adjustments change, weren’t they correct the first time?”

the Bureau says:

“… The important question is not which one (version) represents the absolute truth, but whether those estimates produce wildly different results, and whether the range of estimates provides a reasonable guide to what has actually occurred.”

By their own words they have condemned themselves- “wildly different results” is exactly what has been produced.  Adjustments made in Version 1 were apparently made in error as they have been “corrected” by adjustments in version 2.  Will these adjustments be in error and corrected in version 3?

It’s a joke, a continuing comedy of errors.

I have so far looked at 87 of the 112 Acorn stations.  Next up: New South Wales.

ACORN-SAT 2.0: Tasmania- May the Farce be with you

April 1, 2019

This is the fifth in a series of posts in which I directly compare the most recent version of Australia’s temperature record, ACORN-SAT 2, with that of the previous version, ACORN-SAT 1.  Daily data are directly downloaded from the Bureau of Meteorology. I do not analyse against raw data (available at Climate Data Online), except for particular examples, as I am interested in how different Acorn 2 is from Acorn 1.  The basis for the new version is in the Research Report.  The Bureau has published a new station catalogue with more detailed information, the adjustment summary for each station, plus lists of comparative stations for adjustments and all comparison stations for each site, with explanations of adjustment terminology.  Well worth a look.

See my previous posts for Western Australia, the Northern Territory, Queensland, and South Australia for a general introduction.  An important addition to this general introduction is this paragraph on the ACORN-SAT home page:

The purpose of updating datasets like ACORN-SAT is principally to incorporate data that has been recorded since the last analysis was released, as well as historical paper records that have been recently digitised. ACORN-SAT version 2 also incorporates the findings and recommendations of the Technical Advisory Forum, applies the latest scientific research and understanding and, where applicable, introduces new methodologies. The overall aim of the update to ACORN-SAT is to provide improved estimates of historical changes in climate.

The Context – Tasmania

Figure 1 is a map of Australia showing all of the Bureau’s ACORN-SAT climate monitoring stations.  Tasmania is an island state with a cool marine climate.

Figure 1:  Australian ACORN-SAT stations

Tas map

There are seven Acorn stations in the Tasmanian BOM database.  Differences between Acorn 1 and Acorn 2 are summarized in the following sections.

Largest temperature differences

In maxima, changes to Acorn 1 daily data ranged from +5.4 ℃ at Larapuna (Eddystone Point) to -7.3 ℃ in 1946 at Butlers Gorge applied to individual daily figures.

Figure 2:  Daily changes in maxima from Acorn 1 to Acorn 2 at Butlers Gorge

ButlersGorge max adj

Minima adjustments ranged from -9.7 ℃ to +11.3 ℃ at Butlers Gorge on individual days but with many days adjusted by -2℃ or greater.   Most changes were small but numerous, for example at Launceston where the changes to Acorn 1 ranged between -1 ℃ and +2 ℃ for many years.

Figure 3:  Daily changes in minima from Acorn 1 to Acorn 2 at Launceston:

Launceston min diffs

(Remember, these are adjustments to Acorn 1, which was supposed to be “world’s best practice” seven years ago.  How did the Bureau get it so wrong the first time?  Has world’s best practice changed so much in seven years?)

Record temperatures

New record maxima were established at Butlers Gorge, Cape Bruny Lighthouse, Larapuna (Eddystone Point), and Low Head.

Figure 4:  Three versions of maximum at Low Head 3 February 1912

LowHd record max

New record low temperatures were established at all stations except Butlers Gorge.  Low Head’s minima was reduced by 0.7 ℃ to -2.9 ℃.

Figure 5:  Three versions of minima at Low Head July 1944

LowHd record min

Acorn version 1 had warmed the minima by 0.6 ℃, but version 2 cools version 1 by 0.7 ℃, making it 0.1 ℃ cooler than the raw figure.  Strange things happen in the past!

Quality Control: especially minimum temperatures higher than maximum.

In Acorn 1, five out of the seven stations had at least one example of minimum higher than maximum- including 37 times at Butlers Gorge and 39 times at Low Head (again), where the worst example was minimum 2.1 ℃ above maximum in December 1926.  Blair Trewin claims he has “fixed” this problem (which he concedes was “physically unrealistic”) by adjusting temperatures in Acorn 2 so that the maximum and minimum are the same, so that DTR for the day is zero.  In his words:

A procedure was therefore adopted under which, if a day had a negative diurnal range in the adjusted data, the maximum and minimum temperatures were each corrected to the mean of the original adjusted maximum and adjusted minimum, creating no change in the daily mean.

That is not how he “corrected” the worst Tasmanian example in Acorn 1 (minimum 2.1 ℃ above maximum at Low Head).  Here is a plot of the raw data and changes made by Acorn 1 and Acorn 2 at Low Head in December 1926.

Figure 6:  Low Head temperatures December 1926

LowHd DTR

Acorn 1 maxima (orange line) were reduced too far below Raw (brown). Acorn 1 minima (grey) were too far above raw minima (light blue).  Result: garbage. Acorn 2 has changed maxima (dark red) back above raw, and reduced minima (dark blue) almost to the same value as raw, except on the 17th when it has been made the same as the Acorn 2 maximum.  This is not the “mean of the original adjusted maximum and adjusted minimum”.

The problem was caused by far too large adjustments to maxima, and was fixed by arbitrarily making the minimum on the 17th the same as the maximum, unusually higher than other minima adjustments.

Figure 7 shows the effect Acorn tinkering adjustments have on annual temperature trends at Butlers Gorge.

Figure 7:  Trends in Butlers Gorge minima 1944-2017

ButlersGorge min ann trends

Acorn 1 had this series cooling very slightly at -0.12 ℃ per 100 years but Acorn 2 has reversed the Acorn 1 trend to +0.54 ℃ per 100 years.  (This is restored to what the “raw” trend showed, from a messy record with huge data gaps.)

Conclusion:

There are no additional stations, so Tasmania has only seven stations.

There is no more additional digitized data, except for the period 2012 to 2017.

Large differences between Acorn 1 and Acorn 2 daily data of several degrees Celsius are found at Larapuna and Butlers Gorge.

New record maxima were set at Butlers Gorge, Cape Bruny, Larapuna, and Low Head.  New record low temperatures were established at all stations except Butlers Gorge.

The issue of instances of minima being higher than maxima caused by too vigorous adjustments (37 times at Butlers Gorge and 39 times at Low Head has been “fixed” by arbitrary adjustments.

Excessive adjustments have resulted in Butler Gorge’s Acorn 1 minima trend of -0.12℃ per 100 years being changed to +0.54 ℃ in Acorn 2.

The size of the adjustments only seven years after the “world’s best practice” dataset was launched, is incredible, and demands explanation.  The explanation that Acorn Version 2 “applies the latest scientific research and understanding and, where applicable, introduces new methodologies”, is beyond belief, as nearly every dataset so far examined is vastly different from Acorn Version 1.  This not incremental improvement.

In the ACORN-SAT FAQs, in the answer to:

“Why should the adjustments change, weren’t they correct the first time?”

the Bureau spokesman says:

“… The important question is not which one (version) represents the absolute truth, but whether those estimates produce wildly different results, and whether the range of estimates provides a reasonable guide to what has actually occurred.”

By their own words they have condemned themselves- “wildly different results”  is exactly what has been produced.

 

What a farce.

I have so far looked at 76 of the 112 Acorn stations.  Next up: Victoria.

ACORN-SAT 2.0: South Australia- Science Fiction

March 28, 2019

This is the fourth in a series of posts in which I directly compare the most recent version of Australia’s temperature record, ACORN-SAT 2, with that of the previous version, ACORN-SAT 1.  Daily data are directly downloaded from the Bureau of Meteorology. I do not analyse against raw data (available at Climate Data Online), except for particular examples, as I am interested in how different Acorn 2 is from Acorn 1.  The basis for the new version is in the Research Report.

See my previous posts for Western Australia, the Northern Territory and Queensland for a general introduction.

The Context – South Australia

Figure 1 is a map of Australia showing all of the Bureau’s ACORN-SAT climate monitoring stations.  South Australia has a narrow band of arable country in the south with cool wet winters and hot dry summers, but most of the state is desert.  South Australia achieved notoriety 18 months ago when the whole state endured an electricity blackout- but of course large scale adoption of renewable energy was blameless.

Figure 1:  Australian ACORN-SAT stations

SA map

There are thirteen Acorn stations in the South Australian BOM database.  Differences between Acorn 1 and Acorn 2 are summarized in the following sections.

Largest temperature differences

In maxima, changes to Acorn 1 daily data ranged from +9.7 ℃ in 1996 to -7.6 ℃ in 1993 at Port Lincoln, with changes of +8.5 ℃ on many occasions, applied to individual daily figures.

Figure 2:  Daily changes in maxima from Acorn 1 to Acorn 2 at Port Lincoln

PortLincoln diffs max

Minima adjustments ranged from -5.5 ℃ again at Port Lincoln to +9.1 ℃ at Snowtown, and there were many other large adjustments at other stations as well.  Most changes were small but numerous, for example at Mount Gambier where the changes to Acorn 1 ranged between -2.2 ℃ and +0.5 ℃ for many years.

Figure 3:  Daily changes in minima from Acorn 1 to Acorn 2 at Mount Gambier:

MtGambier diffs min

(Remember, these are adjustments to Acorn 1, which was supposed to be “world’s best practice” seven years ago.  How did the Bureau get it so wrong the first time?  Has world’s best practice changed so much in seven years?)

Record temperatures

Most stations had their record highs actually reduced.  New record maxima were established at two stations, Port Lincoln increased from 46.7 ℃ to 47.9 ℃, and Oodnadatta set a new record of 51.1 degrees Celsius, which is a new record for all of Australia, pipping Carnarvon in WA by 0.1 ℃.

Figure 4:  New version of maxima at Oodnadatta December 1959 – January 1960

Oodnadatta record max

New record low temperatures were established at Cape Borda, Nuriootpa, and Mount Gambier.  Mount Gambier shows the Bureau at its silliest:

Figure 5:  Three versions of minima at Mt Gambier June 1950

MtGambier record min

Acorn version 1 had warmed the minima by 0.4 ℃, but version 2 cools version 1 by 0.6 ℃, making it cooler than the raw figures.

Up, down- what was the ‘correct’ temperature?.

Quality Control: especially minimum temperatures higher than maximum.

In Acorn 1, eight out of the thirteen stations had at least one example of minimum higher than maximum.  Blair Trewin claims he has “fixed” this problem (which he concedes was “physically unrealistic”) by adjusting temperatures in Acorn 2 so that the maximum and minimum are the same, so that DTR for the day is zero.  In his words:

A procedure was therefore adopted under which, if a day had a negative diurnal range in the adjusted data, the maximum and minimum temperatures were each corrected to the mean of the original adjusted maximum and adjusted minimum, creating no change in the daily mean.

That is how he “corrected” the worst South Australian example in Acorn 1 (minimum 2.4 ℃ above maximum at Tarcoola).  Here is a plot of the raw data and changes made by Acorn 1 and Acorn 2 at Tarcoola from 26 April to 5 May 1923.

Figure 6:  Tarcoola temperatures 26 April – 5 May 1923

Tarcoola DTR

Acorn 1 maxima (orange line) were slightly reduced below Raw (brown). Acorn 1 minima (grey) were far above raw minima (light blue).  Result: garbage.  Acorn 2 has made minima (dark blue) about two degrees less than Acorn 1.

The problem was caused by far too large adjustments, as Figure 7 shows:

Figure 7:  Adjustments to raw Tarcoola minima 26 April – 5 May 1923

Tarcoola adjustments

Acorn 1 adjustments to raw minima were as much as 4.4 degrees; Acorn 2 has introduced variety- sometimes lower, sometimes higher.

Figure 8 shows the effect Acorn adjustments have on annual temperature trends.

Figure 8:  Trends in Tarcoola minima 1922-2017

Tarcoola min ann trends

I spliced the old Tarcoola record with Tarcoola Aero which overlapped  from 1998 to 2000 to create a “minimally adjusted” series, shown in blue.  This series is cooling at -0.46 ℃ per 100 years.  Acorn 1 reversed this trend, showing warming at 0.67 ℃ per 100 years, but Acorn 2 has increased the Acorn 1 trend more than three times to +2.43 ℃ per 100 years.

Conclusion:

There are no additional stations, so the network is still extremely sparse.

There is no more additional digitized data.

Large differences between Acorn 1 and Acorn 2 daily data of several degrees Celsius are found at Port Lincoln, Snowtown, Tarcoola, and Mount Gambier.

A new Australian record maximum temperature has been set at 51.1 ℃ at Oodnadatta, Port Lincoln also has a new record, but other locations had record maxima reduced.  New record low temperatures were established at Cape Borda, Nuriootpa, and Mount Gambier.

The issue of instances of minima being higher than maxima caused by too vigorous adjustments has been “fixed” by arbitrary adjustments.

Excessive adjustments have resulted in Tarcoola’s raw minima trend of -0.46℃ per 100 years being changed to +0.67 ℃ in Acorn 1 and an incredible +2.43 ℃ in Acorn 2, an increase of 262% over Acorn 1.

The size of the adjustments only seven years after the “world’s best practice” dataset was launched, is incredible, and demands explanation.

Acorn 2’s adjustments are science fiction.

Next up: Tasmania.

 

ACORN-SAT 2.0: Queensland: Welcome to Dreamworld

February 28, 2019

This is the third in a series of posts in which I directly compare the most recent version of Australia’s temperature record, ACORN-SAT 2, with that of the previous version, ACORN-SAT 1.  Daily data are directly downloaded from the Bureau of Meteorology. I do not analyse against raw data (available at Climate Data Online), except for particular examples, as I am interested in how different Acorn 2 is from Acorn 1.  The basis for the new version is in the Research Report.

See my previous posts for Western Australia and the Northern Territory for a general introduction.

The Context – Queensland

Figure 1 is a map of Australia showing all of the Bureau’s ACORN-SAT climate monitoring stations.  Queensland is in the north-east from monsoonal tropics to mountain temperate to savannah and desert.

Figure 1:  Australian ACORN-SAT stations

Qld map

There are 26 Acorn stations in the Queensland BOM database.  Differences between Acorn 1 and Acorn 2 are summarized in the following sections.

Largest temperature differences

In maxima, changes to Acorn 1 daily data ranged from +7.2C at Burketown in 2003 to -5.2C at Georgetown on many occasions, applied to individual daily figures.

Figure 2:  Daily changes in maxima from Acorn 1 to Acorn 2 at Georgetown

Georgetown diffs

Minima adjustments ranged from -9.1C at Thargomindah to +6.3C at Charleville, and there were many other large adjustments at other stations as well.  Most changes were small but there were many still substantial changes, for example at Longreach where there were some very large changes to Acorn 1, with large numbers between -4C and +2C.

Figure 3:  Daily changes in minima from Acorn 1 to Acorn 2 at Longreach:

Longreach diffs

(Remember, these are adjustments to Acorn 1, which was supposed to be “world’s best practice” seven years ago.  How did the Bureau get it so wrong the first time?  Has world’s best practice changed so much in seven years?)

Record temperatures

New record maxima were established at 10 stations.  These were +0.8C higher than the previous record in Acorn 1 at Burketown (previous record 44.7C to 45.5C).

Figure 4:  Three versions of maxima at Burketown December 1934

Burketown max 1934

A new record low temperature was established at Palmerville, way up north in tropical Cape Yorke Peninsula, where the ridiculous Acorn 1 temperature of -2.4C was reduced even further to -3.1C.  Unbelievable- the record low at Charters Towers, 500km south, is 1.1C.  The record low at Rockhampton, 1,000 km south, is -1C.

Figure 5:  Three versions of minima at Palmerville June 1913

Palmerville min 1913

New lows were also established at 10 other stations.

Apparently the adjustments made to raw data in Acorn 1 weren’t big enough.

Quality Control: especially minimum temperatures higher than maximum.

In Acorn 1, 15 out of the 26 stations had at least one example of minimum higher than maximum.  Blair Trewin has “fixed” this problem (which he concedes was “physically unrealistic”) by adjusting temperatures in Acorn 2 so that the maximum and minimum are the same, so that DTR for the day is zero.  In his words:

A procedure was therefore adopted under which, if a day had a negative diurnal range in the adjusted data, the maximum and minimum temperatures were each corrected to the mean of the original adjusted maximum and adjusted minimum, creating no change in the daily mean.

That is how he “corrected” the worst Queensland example in Acorn 1 (minimum 2.8C above maximum at tropical Mackay).  Here is a plot of the raw data and changes made by Acorn 1 and Acorn 2 at Mackay from 25 to 31 August 1953.

Figure 6:  Mackay Aerodrome data 25-31 August 1953

Mackay August 1953

Acorn 1 maxima (brown line) were slightly reduced below Raw (bright green) until 27 August but had a major adjustment on the 28th, far below Raw minima (olive) and Acorn 1 minima (blue).  Result: garbage.  Acorn 2 has made minima (purple) less than Acorn 1.  Acorn 2 maxima (red) are slightly less than Acorn 1 except on the 28th when the maximum has been made the same as minimum.

The problem was caused by far too large adjustments.

The problem has been “fixed” by making more arbitrary adjustments, but large adjustments remain.

Amberley:

Amberley came under scrutiny after Acorn 1 because of a major adjustment to minima to account for a discontinuity in the 1980s.  I compare before and after annual data.

Figure 7:  Amberley Minima

Amberley min annual

There is a discontinuity in the raw data, so the negative trend is probably too steep.  However, the adjustments in Acorn 1 were far too great.  Acorn 2 is a slight improvement: the trend is now +2.11C per 100 years instead of +2.62C.

Barcaldine:

Barcaldine’s raw data was not supposed to be adjusted in Acorn 1- at least that was claimed in the Table guidance notes of the Table of Adjustments released in 2014.  However, there were some small one-off adjustments to maxima in Acorn 1: +0.1C in 1962, 1995, and 1996, and -0.1C in 2011. However, both maxima and minima have been strongly adjusted in Acorn 2.  Here is Barcaldine’s Tmax:

Figure 8:  Barcaldine Maxima

Barcaldine max annual

That’s a 52% increase in annual trends!

Conclusion:

There are no additional stations, so the network is still extremely sparse.

There is a very small amount of additional digitized data.

Burketown, Georgetown, Longreach, Normanton, and Richmond all had large differences in maxima between Acorn 1 and Acorn 2 daily data of over five degrees Celsius.  Charters Towers, Longreach, Normanton, Palmerville, and Thargomindah had greater than five degree differences in minima.

New record maximum and minimum temperatures have been set.  Palmerville’s new recod low is especially preposterous.

The issue of instances of minima being higher than maxima caused by too vigorous adjustments has been “fixed” by arbitrary adjustments.

Amberley’s minima adjustments have been reduced.

Barcaldine’s raw data was not adjusted in Acorn 1, but both maxima and minima have been  adjusted in Acorn 2.

The size of the adjustments only seven years after the “world’s best practice” dataset was launched, is incredible, and demands explanation.

You don’t have to go to the Gold Coast to see Dreamworld- it’s in the Acorn 2 adjustments.

I will be concentrating on another project for a few weeks so may not post for a while, but when I do, next will be South Australia.

ACORN 2: Rutherglen-Digging a Deeper Hole

February 26, 2019

Rutherglen is back in the news again, so here’s my two bob’s worth.

Acorn 2 has increased the warming trend in annual minima from +1.71C per 100 years to +1.8C per 100 years:

Figure 1:  Rutherglen annual minima

Rutherglen annuals min

Rutherglen’s lowest minimum has been reduced from -7.9C to -8C.

The “corrections” to Acorn 1 are now from 31 December 2010:

Figure 2: Acorn 2 minus Acorn 1 daily values

Rutherglen Tmin diffs

Who knew thermometers were reading a much as 1.2 degrees too warm in 2010?  (The annual mean differences between Acorn 1 and Acorn 2 for the years before 2011 are from 0.5C to 0.7C).

So, is the new version of Acorn an improvement on the homogenization in Acorn 1 from seven years ago?

As a result of the media interest in Rutherglen, in 2014 the Bureau published this plot, showing Rutherglen’s raw data compared with the homogenized data from Wagga Wagga, Deniliquin, and Kerang.

Figure 3:  BOM justification for adjustments

Rutherglen BOM comparison chart

Comparing raw data from one station with adjusted data from other stations is hardly a valid argument.

Back in 2014, I posited a test for the validity of adjustments.  The aim of homogenizing is to adjust the temperature record to make a “best estimate” of what the temperature should have been.  This is achieved by pairwise comparison between the candidate site and 10 reference sites.

By comparing Rutherglen’s raw and adjusted data with that of each of the stations used in the homogenizing process, we can see how the Rutherglen record compares with its neighbours before and after homogenising.

Subtracting the mean of neighbours’ temperature anomalies from those of Rutherglen, we can tell how well the raw data compare, and how well the adjusted data compare.

Figure 4:  2014 comparison of differences

2014 plot

Back then, it was obvious that Rutherglen minima were cooling at about the same rate as the neighbours, and that the Acorn 1 adjustments were much too great.

Applying exactly the same methodology now, with complete dataset extended to 2017, we see that Rutherglen is cooling very slightly more than neighbours, while Acorn 2 is even more out of touch with the regional reality.

Figure 5:  Rutherglen differences 2019

Rutherglen tmin avg comps

The Acorn 2 adjustments are much too large, and have created an even stronger warming trend.

FAIL.

ACORN-SAT 2: Eucla: The Devil in the detail

February 18, 2019

I’m having a break from looking at Acorn 2 data from Queensland.  I’ve been wondering:  what’s going on?  What’s beneath these changes?  In particular, I was struck by statements in the accompanying Research Paper that

In total, there were 966 adjustments applied in version 2 of the ACORN-SAT dataset, 463 for maximum temperature and 503 for minimum temperature.”

The Bureau is referring to breakpoints in the data where adjustments are applied to all previous years.  In the daily data, there are tens of thousands of adjustments at each station.

For example, in Eucla’s Tmax record, there are 34,145 daily datapoints; 34,144 in Acorn 1; and 33,858 in Acorn 2.  There are  10,190 instances where Acorn 1 makes no change to raw data, and 9,312 in Acorn 2.  Most of the instances of no adjustments are since 1995.  Before then almost every day has been adjusted.

And the devil is in the detail.

The following plots show how adjustments are applied to the range of raw maxima.  First Acorn 1.

Figure 1:  Acorn 1 adjustments as applied to raw maxima at Eucla

Ac1 raw adj

Figure 2:  Acorn 2 adjustments as applied to raw maxima

Ac2 raw adj

Acorn 2 removes the large negative adjustments for temperatures in the high 30s, and the spread is wider for very high temperatures.  So far so good.

Figure 3 shows where many of these adjustments are made.

Figure 3:  Acorn 2 and  raw maxima

Eucla 1913-2017

Between 1930 and 1995 many high temperature spikes are reduced by 5 degrees and more.

For example, here is November 1960.

Figure 4:  Raw, Acorn 1, and Acorn 2 in November 1960

Eucla Nov 1960

The Bureau can truthfully claim that there is a balance between positive and negative adjustments.

However, note how all temperatures over 35C have been reduced by five degrees.  This is common across these years.

Perhaps temperatures on very hot days at Eucla in the 1960s were exaggerated?  Perhaps they were not read accurately?

If this pattern of hot day reductions is generally followed at stations across large regions, e.g. southern Australia, the effect will be that climate analysis based on Acorn 2 will show that past extremes were generally not as high as nowadays.

And that can’t be a bad thing for the meme.