Early weather data theme

Linden Ashcroft and David Karoly

SEARCH final project meeting

2 August 2012

William Dawes: Australia’s first meteorologist

• Lt. William Dawes maintained a weather diary at Dawes Point, Sydney (Sept 1788 – Dec 1791)

• 4 to 6 times daily temperature, pressure, winds and remarks

• Found at the Royal Society London by an Australian student in 1980s

• Data digitised and analysed in 2008, Gergis et al (2009), AMOJ, 58, 83-98

Images: Richard Read (1821) Dawes Battery Point, SLNSW; J.Gergis, Royal Society of London 2009.

William Dawes: Australia’s first meteorologist

February 1791: ‘The heat was so excessive that immense numbers of the large fox bat were seen…dropping into the water…many dropped dead while on the wing…’ Hunter (1793)

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Data collection action!

SE Australian data coverage, 1788–1910

28 June 1836

Key sources: Sydney newspapers 1826–1848

Images: National Library of Australia (NLA, www.trove.nla.gov.au)

Key sources: Government Gazette abstracts 1840-1855

Images: NSW Government Gazette, State Library of Victoria (SLV).

Australian Joint Copying Projectship logbooks

• Logbooks of 33 ships that passed through Australian waters during 1788–1890 identified from Log of Logs inventory

Image: Allen, Frank, 1787, National Maritime Museum.

• Daily noon temperatures and pressure recorded in a ship log onboard the Sirius by William Bradley during the 8 month First Fleet voyage from England to Australia in 1787–1788

• Saw snow as they rounded Tasmania in January (summer!) 1788, very cold and wet, sails ripped in howling winds, convicts on their knees at prayers

• Some of the earliest meteorological observations from the Southern Hemisphere

Source: Gergis, Brohan and Allan, Weather 2010

First Fleet weather, 1787–1788

Images: George Raper, 1791, State Library of NSW (SLNSW); Gergis, Brohan and Allan (2010).

Long-term temperature stations, 1860–2009

Image: BoM

Data quality

SE Australian temperature 1860–2010

Ashcroft et al. (in review)

SE Australian maximum temperature 1860-2010

Ashcroft et al. (in review)

Pressure network 1860–2009

SE Australian pressure variations 1860–2009

Long-term rainfall stations 1860–2008

SE Australian rainfall 1860-2009

Observations vs 20th Century Reanalysis

R=0.71

R=0.71

R=0.78

R=0.59

Sydney Rainfall 1832–2011

Image: Garling, Frederick (1842–1860), South Head, SLNSW, a128220.

• Grey=Documentary data• Purple=Instrumental data

Gergis and Ashcroft, 2012 (in revision).

Eastern NSW rainfall 1788–2008

SE Australian climate 1860–2009

Multivariate path analysis

© Copyright The University of Melbourne 2008

SE Australian minimum temperature, 1860–2010

Ashcroft et al. (in review)

9 April 1822 H Th Ba 10 April 1822 H Th Ba Towards Bass Straight 1 Towards Bass Straight 1 2 61.75 30.34 2 61.75 30.26 Lat 41o 43' 11" S 3 Lat 41.7o 7' 57" S 3 Lon 137o 36' 54" E 4 62 30.33 Lon 140o 22' 59" E 4 61.75 30.28 5 5 6 62 30.33 6 61.5 30.28 7 7 8 61.5 30.33 8 62 30.25 9 9 10 62 30.33 10 62 30.25 11 11 12 61.75 30.32 12 61.5 30.24 13 13 14 61 30.31 14 60.5 30.24 15 15 16 61 30.29 16 61 30.24 17 17 18 60.5 30.28 18 61 30.24 19 19 20 60 30.28 20 60.5 30.24 21 21 22 61 30.28 22 60.75 30.27 23 23 24 61 30.27 24 62 30.26

Example Shipping Log HM Survey Vessel Bathurst, 1821–1822

Digitising Instrumental Data