Caitlin Howlett , Climate History Australia

BAMOS July 2021

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Summer in Kings Park , Perth , circa 1905 . Source : State Library of Western Australia .

In 2020 and 2021 , Climate History Australia ran two citizen science projects on Zooniverse . The aim was to transcribe observations from 19th century handwritten meteorological journals from Adelaide and Perth .

The projects recovered a total of 26 years ' worth of historical climate observations . We had more than 1,790 volunteers on Zooniverse , and collected a combined total of more than 67,400 previously untranscribed historical weather observations .

Adelaide Survey Office

• Recovered the period 1843 to 1856

• Collected 8 years of missing data ( plus overlap )

• Created over 33,400 classifications

• Project ran for 77 days ; from 8 September to 24 November , 2020 .

Perth . Two sites : Survey Office & Botanical Gardens

• Recovered the period 1880 – 1900

• Collected 18 years of missing data ( plus overlap )

• Created over 34,000 classifications

• Project ran for 72 days ; from 20 April to 1 July , 2021 .

These observations will help link together historical and modern weather observations to provide near-continuous weather records for Perth back to 1830 , and Adelaide back to 1836 .

This means our volunteers have helped develop the oldestknown meteorological observations for Australia — which are also likely to be the longest , near-continuous daily records for all of the Southern Hemisphere !

The 19th century historical records our volunteers helped transcribe are critical for understanding Australia ’ s preindustrial climate , and how climate change has impacted extreme weather events . Extreme weather events in the future are predicted to be even more frequent and intense than they were in the past .

Some of the previously unknown extreme weather we ’ ve uncovered in our Zooniverse citizen science projects so far , includes :

• A week-long heatwave in Adelaide , February 1847

• A severe lightning storm with a cold snap , floods and large hailstones in Adelaide , July 1847

• Severe and widespread flooding across Adelaide : August , October & November 1848

• A deadly heatwave in Perth , 1 – 4 January 1896

• Storm in Perth , July 1898

• Three incidences of ‘ hoar frosts ’ in Perth , July & August 1899 .

In 2020 , our team published a research paper outlining some of the historical weather extremes in Adelaide , South Australia . We found that snow was once a regular feature of the southern Australian climate in the 1800s . However , the Zooniverse citizen science projects have helped to close some data gaps for Adelaide , and open up new daily datasets for Perth .

Our researchers can now analyse what will become Australia ’ s longest daily weather records across a large area of Southern Australia . The full analysis and results for this newly transcribed data will take time , which we will publish in the scientific literature in due course and share on our website : www . climatehistory . com . au .