The Australian Temperature Record- Part 6: Victoria

Ken Stewart, June 2010

Each new state that I study brings a fresh surprise, and that certainly applies to Victoria.   My Great-Grandparents were farmers near Glenrowan in Victoria.  They lived near the Kellys.  Ned Kelly and his gang of bushrangers were horse thieves, bank robbers, and murderers, but have passed into history as folklore heroes.  The expression “Ned Kelly’s not dead yet!” is an Australianism meaning “What a rip off!”  This can be used in situations such as buying something and finding it has a huge mark up, say 133%.  The significance of this item of trivia will soon become obvious.

The Australian Bureau of Meteorology (BOM) has its headquarters in Victoria’s capital, Melbourne, and develops its climate Trend Maps and Time Series graphs from 100 sites nationwide, comprising the High Quality Australian Site Network.  13 of these are in Victoria. 

Here is a map of the sites:

Here’s the Trend Map

And Time Series Graph:

As you can see, BOM declares a warming trend of 0.09C per decade, or 0.9 degrees C for the last 100 years.

I am engaged in what I believe is the first ever independent study of the complete High Quality Australian Site Network, and as part of that project have analysed the data from the Victorian sites.  I averaged maxima and minima for all stations at each site, then compared with the High Quality means.  A spokesperson for BOM has asserted that: 

“On the issue of adjustments you find that these have a near zero impact on the all Australian temperature because these tend to be equally positive and negative across the network (as would be expected given they are adjustments for random station changes).”

Compare this with the results:

By these calculations (averaging the trend at each site) the raw trend is 0.35 degrees C per 100 years, and the High Quality state trend is 0.83C.  That’s a warming bias of 133%!

When the annual records for all 13 sites are averaged and graphed, the official trend is 0.85 C.  (BOM rounds to 0.9).

Graph of Raw and High Quality data for the State of Victoria:

Also note that the raw trend is practically identical to the table above, and the warming bias  for the state becomes 142.8%. 

This is a graph of the magnitude of the adjustments to the raw data from least to greatest.

Note that two stations’ trends are unchanged, one is cooled, and the rest have strong warming adjustments.  Omeo gets the gong for the greatest adjustment in the whole of Australia (so far).

Let’s look at these 13 records.

Three stations (Mildura, East Sale, and Cashmore) were listed in 1996 as being Urban, and therefore not supposed to be used in developing the temperature record.  Yet there they are.  As well, Laverton is now encroached by the outer suburbs of Melbourne and should also be regarded as Urban.

Because of the poor quality of records, I frequently had to splice data to see what was happening. My splices are not corrections but attempts to match separate records.  All increase the raw trend.

Mildura raw:

Note the Merbein CSIRO farm’s data is close to the airport’s, so the adjusted data is a good match:

Swan Hill raw:

The homogenised data has been adjusted down about 0.6, resulting in a steeper warming trend.

Kerang– shows Boort as well.  I used Boort less 0.1 to infill the splice.

But the adjustments increase the warming.

Nhill in western Victoria, shows cooling of about -0.2C.

But that has been turned right around!

A change of 0.95C in trend!

Ararat Prison and Ararat town data do not overlap, and there are large gaps:

Hard to join the two, so I checked Stawell.

There are overlaps with both datasets, so I reduced Stawell by 1.0.

 A good match but 0.3 above the prison, so I reduced the PO data by 0.3  and spliced with the prison.

So how did they make that adjustment?

Cashmore Airport, in SW Victoria:

To make a long period record, BOM needs to splice with other records.  As it happens, the Portland Airport was moved to Cashmore (about 14 km away) to get away from the aluminium refinery.  There are in fact five separate records for the Portland area.

The original Portland site with many gaps was superceded by Cape Nelson Comparison in the 1950s.  The Airport (about 1.5km from the old Portland site) recorded data for a few years with a good overlap with the lighthouse about 9km away.  This is the splice I made: old Portland less 0.3; Cape Nelson Comparison less 0.8 and Cape Nelson less 1.05 to match Cashmore.

I think that is a fair splice, but look at BOM’s adjustment:

Remember, Cashmore Airport is built from urban data, and shouldn’t have been used by BOM at all.

Cape Otway Lighthouse raw:

And adjusted:

Warmed again.

Laverton RAAF.   It was once out in the country.  Explosives factories were built nearby (out of town for obvious reasons) but in recent years Melbourne has expanded and Laverton is an outer suburb.

No problems with the adjustments:

Rutherglen Research Farm raw:

Nearby Wahgunyah, Viticulture College, and Post Office compared to the Research Farm:

which shows a good match between Post office and Viticulture College, and apart from 1922-1923-1924 the Viticulture record considerably above Rutherglen- and cooling.  So the flat Rutherglen record should be reliable.  However…

Omeo:

Cooling trend if you ignore 1935!  But Omeo has been adjusted:

That’s the biggest adjustment so far!

East Sale Airport raw:

No overlap at all.  But there are several stations in the Sale area:

Note the very close match of Maffra Forestry (16.6km away) with the other records, except for around 1970.  There was sure to be a discontinuity in the Maffra records, but to match the Airport I reduced the whole Maffra record by 0.3 to make a useable splice:

The splice gives a trend of less than 0.3C, but compare with the High Quality trend:

Wilson’s Promontory Lighthouse, the most southerly point of the Australian continent:

Slightly warmed, who knows why. 

Gabo Island Lighthouse, just off the far eastern tip of Victoria:

Adjusted:

The only station out of the 13 to have its trend reduced!

Conclusion:

There is a distinct warming trend in Victoria since the 1960s, which has been especially marked in the last 15 years.

The first half of the record shows a cooling trend.  BOM’s adjustments have attempted to remove this.

2007, not 2009, was the warmest year in the past 100 years.

Three stations identified as urban in 1996 have been included.

Many stations’ data have been arbitrarily adjusted to cool earlier years

Only one station has had its trend reduced.  Two are essentially unchanged.

Ten of Victoria’s 13 stations have been adjusted to increase the warming trend, to the extent that there is a warming bias of at least 133%, more likely 143%. 

These adjustments, and the Australian temperature record to which they contribute, are plainly not to be trusted.  

Ned Kelly’s not dead yet, and he works in the Bureau of Meteorology.   133%? I don’t buy it.

Progress report on the Australian High Quality Site Network:

Sites checked:             83  out of 100

Raw trend:                  +0.72 degrees C/ 100 years

High Quality trend:     +0.96

Average difference:    +0.24

Warming bias:           33.22%

There will have to be a massive cooling bias in the remaining 17 stations to return the overall Australian adjustments to neutral.