Sunset at Seacliff Beach Adelaide

Prior to 1979, the primary temperature recording station in Adelaide was on West Terrace.  The record is continuous from 1887 to 1979 before it was closed down and replaced by the Kent Town site.  The two records also overlap each other by two years, so gives us a good idea as to the relationship between the two records given their different locations.

Viewing the West Tce and Kent Town records gives us  a much more honest picture of Adelaide’s temperature history than the official Bom (supposed) High Quality temperature record, which bears no resemblance to any of Adelaide’s original records.

The two years in which both records were active are pretty closely aligned.  The Annual Max Temps differ by only 0.14°C, with Kent Town being slightly warmer.

West tce + kent town 77 + 78

Maximum Monthly temperatures

The minimum temps are lower at Kent Town over the two year period.

West tce + kent town 77 + 78 mins

Minimum Monthly Temperatures

One could speculate about why the Minimum temps were warmer at West Tce while the Maximum temps were cooler.  It could be as simple as, West Terrace being on the western side of Adelaide, impacted more often by the prevailing coastal winds during the day and by the prevailing hills winds (blowing through the city) by night.

Here are the two maximum records “joined at the hip”.

West Tce + Kent Town Max Temps unadjusted

Doesn’t seem to be much runaway warming in this record.

The Max temp record almost looks cyclic around about a 100 years or so.  If that ends up being true, we should have a slow drop in maximum temps over the next 50 odd years back to 1950/60’s type temperatures.  Of course this is pure speculation, but weather and climate do tend to occur in cycles, so could quite easily be true.

The average monthly minimum record is incredibly stable over this period.   Bit of rise around the sixties and seventies, but nothing to get exited about and start taxing the hell out of the every Australian!   Minimum temperature’s tend to be more prone to UHI (urban heat island effect), and so is completely expected considering the population increases and increased residential, building and business activity in the city and inner suburbs around this period.  

West Tce + Kent Town Min Temps unadjusted

So how does all this compare with the Bom High Quality long term  record for Adelaide?

The first graph shows the West Tce + Kent Town raw annual maximum data.  The second graph shows the Bom High Quality annual maximum  temperature data (with trends).

West Tce + Kent Town Max Temps + trend

Bom HiQ Kent town Max temp

The trend from West Tce + Kent town (top graph) is about 0.2°C per century.  Statistically insignificant, while the Bom HQ data has a trend of 1.2°C per century.  Hmmmm.

I cannot fathom how they could be so different.  Kenskingdom reckon’s that it was a composite of many of the Adelaide records (see previous post), while I am not so sure that it was that complicated.

I had a look at the actual relationship between the West Tce + Kent Town and the HQ data sets.

This is what I found.

HQ changes

The HQ data appears to be totally based on the West terrace data, but with systematic but crude alterations.  The temperatures prior to 1979 have been cooled, and the cooling has been “step” increased at 1978 (0.1°C decrease), 1951 (a further 0.3°C cooling), and 1926 (a further 0.3°C cooling).

To produce the High Quality Adelaide temperature record, the West Terrace record has been adjusted as follows:

From 1952 to 1978 the record has been cooled 0.1°C

From 1927 to 1951 the record has been cooled 0.4°C

 From 1910 to 1926 the record has been cooled 0.7°C.

The minimum record has had even greater changes.

HQ changes mins

Except for a couple of years with spurious data, the changes are crude but clearly systematic.  No clever algorithm to disguise and hide this data. 

From 1946 to 1977 the record has been cooled 0.8°C

From 1911 to 1945 the record has been cooled a wopping 1.2°C

Is this is your “global warming”.  Created by man, yes, but not by driving cars or heating your home, but in the very heart of the Bureau of Meteorology.

Now before anyone goes off about the temperature difference from West Tce to Kent Town.  Consider the fact that both the maximum and the minimum records were cooled in the past, when it was only the minimum record that increased with the site move.   It is clear that only the West Tce minimum record should have been cooled due to location change, and the extent of the changes in both minima and maxima are not justified.  In addition to this, there is no apparent adjustments to account for UHI in the records.

Global warming (in Adelaide) appears only in the calculations and the adjustments in the Bom data.  Not in the instrumental records. 

Adelaide, despite having some very high temperatures occasionally (40°C+), enjoys a mild climate as the low variation in temperatures show.  The top photo (Seacliff  Beach) was taken on the 21st January 2013.  A typically perfect Adelaide summer day with a maximum 30°C and a minimum of 15.8°C.    Great place to live.