Alice Springs–A Closer Look At The Temperature Record

By Paul Homewood

Before After

As promised, I have a had a good delve into the Australian Bureau of Meteorology’s records concerning Alice Springs, where GHCN have completely corrupted the temperature history by cooling the past.

First, a look at the size and timing of the adjustments.

Between 1940 and 1974, the adjustment has reduced the original temperature record by about 2 degrees centigrade. In 1975, the adjustment halved to about 1 degree and remained around this level till 2009. In 2010, the adjustment disappears.

OK, it may be possible that the original readings were in error, or that there have been changes to the station location or methods of observation which might have caused the temperature record to be unreliable. So what does the BOM’s database tell us? A quick check shows that their records tally with the original GHCN V2.0 dataset, in use till last year, as these two graphs for Max and Min temperatures illustrate.

Temperatures are pretty much the same now as they were 70 years ago. The Bureau’s records, however tell us a lot more. The metadata for Alice Springs is shown in considerable detail and confirms the following :-

The station has been at the same site since 1941. (Elsewhere the BOM describe how they will give a station a new reference number if it has moved more than 2 km.)

There has been no change in hours of observation since 1941. All temperatures are recorded every three hours and daily temperatures logged at 9.00 am, a practice used throughout its 71 year history.

There have been no significant changes in equipment, and certainly none at all around 1974 or 2010 when the step changes occurred in adjustments.

The GHCN Technical Log makes it crystal clear. Homogenisation Adjustments are designed to “remove the impact of non-climatic changes “ such as relocations, changes in instrumentation and observational practices. There have been no such changes, so there should be no adjustment.

One further observation.The weather station at Alice Springs is located at this airport, yet GISS make absolutely no allowance at all for UHI effect. Does anyone honestly believe that the development of a modern airport like this has not had an effect on temperatures, when compared to the grass strip that would have been there 70 years ago?