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The mysterious lost hot Sunday in Bourke, did it really happen?

Posted By Joanne Nova On September 3, 2014 @ 3:43 pm In Global Warming | Comments Disabled

 Was January 3rd 1909 in Bourke one of Australia’s hottest days ever?

The historic records say “125F” — or 51.7C.
The BOM say it was an observer error.

Bourke and neighboring stations in NSW and QLD Australia

Blair Trewin wrote a paper looking at the extreme highs in 1997. The Bourke record was made on a Sunday and in that particular year there are no records on other Sundays. On the other hand, I wonder what station observer would not notice a day that was 125F and head in to work to see exactly how high it was. The number 125F was handwritten in and underlined. You’d think observers would know it was a special figure, and pay attention.

The town of Bourke got a Stephenson Screen only a few months beforehand in August 1908, so it had good modern equipment. But Trewin thinks the record is an observer error, and points out that it was a lot warmer in Bourke than in other surrounding towns like Thargomindah, Walgett, and Coonable, and by about 6.9C degrees, which is an unusual gap. During the rest of the month Bourke was “not exceptionally hot compared to other stations”. Fair point. But Jen Marohasy responds that “newspaper reports show the nearest station, Brewarrina, had recorded 123F (50.6C) on the same day (January 3, 1909).“  Official Brewarrina records don’t start until 1911.

For scale. Bourke and neighbors.

I can understand why there is some debate about this record, but I don’t understand how it’s scientifically accurate to issue press releases declaring that we know Australian temperature trends, or understand how our extremes have changed. The statement “hotter than any time since 1910″ might be technically accurate in a way, but is very misleading when it relies on guesses about which high numbers were accidents, and avoids any mention at all of the hot weather before 1910.

It is great to see Graham Lloyd is fearless in following the data and arguments.

The Australian “Heat off Bourke after Bureau of Meteorology revision”

THE removal of a longstanding temperature record at Bourke of 125 degrees Fahrenheit (51.7C) set in 1909 was the result of a critical 1997 paper that revised a string of records and brought Australia’s hottest recorded temperature into the second half of the 20th century.

Until the paper by Blair Trewin, who is now a leading climate scientist at the Bureau of Meteorology, Australia’s hottest recorded temperature was 53.1C at Cloncurry on January 16, 1889.

But after revision, the record has been accepted as the 50.7C recorded at Oodnadatta, South Australia, on January 2, 1960.

However, Jennifer Marohasy, who has questioned the ­bureau about changes to the historic temperature record, said the nearest station, Brewarrina, had recorded 123F (50.6C) on the same day (January 3, 1909).

The Brewarrina temperature record is widely reported in historic newspaper articles but the bureau’s online temperature record for Brewarrina does not start until January 1, 1911.

“In fact 125 is clearly written into the Bourke ledger for Sunday 3rd January in the pen that was being used at that time,’’ she said. “The entry is also underlined.”

“At the time all records were audited and a summary written at the end of the month.

“This summary clearly states that the maximum temperature on 3 January 1909 was 125F.”

The gap between Bourke and other towns (excluding Brewarrina) was larger than usual on the record day.

From the Trewin paper. There were originally two recordings of 125F two days in a row:

“The original manuscript for Bourke shows temperatures of 125F (44.4C) on both 2 and 3 January. The observation on 2 January has been correct on the manuscript to 112F (44.4C) which is consistent with the temperatures over the region, and with the 1500 LST temperature of 110F (43.3C). The 3 January observation was not corrected. However 3 January was a Sunday, and no other observations were made on this day (as was the usual practice at Bourke, and many other stations, at the time). It is therefore likely that the observation is actually the maximum temperature for the 48 hours to 0900, 4 January, and therefore it would be affected by the same error which was corrected in the case of the 2 January observation.

Reports from those stations in the region which did take observations on both days suggest that temperatures in the region on 3 January were similar to those of 2 January.”

Given that Brewarrina unofficial records show 123F, this explanation above doesn’t seem very convincing.

From the national newspaper archives:  “Great Heat Wave” Jan 5th, 1909 h/t to Chris Gillham.

Bourke. – The heat on Sunday was terrific. The thermometer registered 125 degrees; . At 9 o’clock p.m. it-was still over a hundred. It was hotter than any day during the heat-wave 12 years ago. The lowest shade heat for the past five days was 114 degrees.

“Brewarrina. – On Sunday the thermometer at the post office registered 123 degrees in the shade.“.

In Cobar the temperature was 117F. h/t to Siliggy.

“123 in the shade at Goodooga, 124 at Brewarriner, and 117 at Riverstone on Sunday.” Cobargo Chronical 8th Jan 1909

It seems more likely the operator wrote the Sunday reading in for Saturday accidentally, then it was corrected and moved to Sunday.

REFERENCE

Trewin, Blair (1997) Another look at Australia’s record high temperature, Aust. Met. Mag. 46 (1997) 251-256

 

 

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