Historic weather records hailed for its accuracy

Algernon Belfield's diary
Grazier Algernon Belfield's diaries were diligently documented and are today invaluable to weather researchers. Image: Howard Bridgman

The historical weather diaries of Australian grazier, Algernon Belfield, have been internationally recognised for their high quality in a new publication from the United Kingdom’s Royal Meteorological Society.

Algernon Belfield took weather measurements every day at his rural property, Eversleigh, near Armidale, NSW, between 1877 and 1922.

Dr Linden Ashcroft, a co-author of a study into Belfield’s work that has been released this week, said his diaries survived for many years in an attic until his grandson, Richard Belfield of Armidale, discovered them in a box in 2009 and donated them to the University of New England.

A lecturer in Science Communication and Climate Science at the University of Melbourne, Dr Ashcroft has spent the last four years evaluating Belfield’s measurements with weather and historical researchers from the Universities of New England and Newcastle.

“We considered things like the location of Algernon’s weather instruments,” she said. “Did he move his equipment at all during that 45-year period? Did he round up or down when reading the thermometer? These small things can have a big impact on the accuracy of a data set, so we had to be real detectives.”

The publication’s lead author, Associate Professor Howard Bridgman from the University of Newcastle, said it was “very unusual to find a 45-year-long historical weather record like Algernon’s from a rural location in Australia”.

“Belfield’s diaries are also valuable because of the number of variables he recorded. He diligently documented temperature, atmospheric pressure, wind speed, rainfall, even the amount of cloud,” said Associate Professor Bridgman. “It’s a real find.”

The research team first had to scan the 140 year old diaries, and then transcribe the observations into spreadsheets. Volunteers helped with this step, with citizen scientists from Australia and overseas pitching in to type up the pages.

Once this process was complete, the researchers rigorously examined the data set for quality.

The results — published this week in the Royal Meteorological Society’s Geoscience Data Journal - found that the Eversleigh records are on par with official observations from the Bureau of Meteorology.

“Now we’re confident that most of Algernon’s record is scientifically sound, we can explore what his observations tell us about the past, present and future climate,” said Dr Ashcroft.

“Given the current drought, it’s vital that we learn more about our droughts of the past. Algernon’s diaries will certainly help with that.”