From Jo Nova
The mysterious BOM disinterest in hot historic Australian Stevenson screen temperatures
When it comes to our rare high-quality historic records, and the real long term trends of Australian weather, the silence is striking. There are some excellent historical records of long term temperature data from the late 1800s in Australia, which lie underused and largely ignored by the BOM.
For the BOM, history almost appears to start in 1910, yet the modern type of Stevenson screen thermometer was installed across Australia starting as early as 1884 in Adelaide. Most stations in Queensland were converted as long ago as 1889 and in South Australia by 1892. Though states like NSW and Victoria were delayed until 1908.
Here’s a photo of the ones in Brisbane in 1890.
The BOM don’t often mention all their older temperature data. They argue that all the recordings then were not taken with standardized equipment. The BOM prefers to start long term graphs and trends from 1910 (except when they start in 1950 or 1970, or 1993).
The BOM was set up in 1908. Before that there were Stevenson screens going in all over Australia, but somehow these records appear uninteresting to climate researchers. Could it be that the late 1800s would have been more captivating if they were colder? In the late 1800′s there was the widespread heatwave of 1896 killing hundreds of people and recording 50C plus temperatures across the continent as well as the infamous Federation Drought?
Figure that if the BOM were curious about long term natural trends, it would not be impossible for a PhD student to compare the distant past and estimate those long trends. (If two stands of trees in 1200AD are accurate to 0.1C, why not actual, but non-standard thermometers in 1890?)
Not only were some stations using Stevenson screens in Australia, but other types of non-standard but common screens were documented, along with sites, and there were studies of overlapping data. (Though there were also some highly irregular sites that would defy analysis). More to the point, with millions in government grants available for research, the BOM could even recreate some historic sites and do modern side-by-side comparisons. Surely in the space age we can figure out the temperature differences of wooden boxes?
Suppose for a moment that the old records showed cool summers, or demonstrated that Australia had warmed by two degrees instead of one? Wouldn’t there rather be a flood of papers adjusting and homogenising Glaishers and Stevensons, and perhaps even sheds and octagons? Whole new museums could spring forth, recreating sacred meteorology stations from 1862. School children would file by and gasp!
The British CRU (University of East Anglia) reports Australian trends from 1850
Jennifer Marohasy wonders where the CRU got the data that the BOM don’t want to use. She has beenwriting about the Stevenson screens and asking the Australian BOM questions like this and more. Warwick Hughes has been analyzing these old records even longer. His paper in 1995 provoked the Neville Nicholls reply of 1996 (which is used to create the map below).
Above, the year that Nicholls 1996 describes “most” stations as being shifted to Stevenson screens.
There were a few late exceptions to these dates.
Although there were many sites, especially in NSW and Victoria that didn’t get Stevenson screens until sometime in 1907, vast areas of Australia in WA, Queensland and South Australia have accurate older data. When “hottest” ever records for these states are announced, why are the older high quality measurements almost invisible?
Full article here