BAMOS Vol 31 No.3 September 2018 | Page 18

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BAMOS Sep 2018

Article

Sydney rainfall and sea temperature from the mid-20th century

George Cresswell Email : gcresswell1 @ bigpond . com
In late 1969 , shortly after I ’ d walked in the door of the Cronulla CSIRO marine laboratories , I was handed a hand-drawn 0.6x0.3m plot of Sydney rainfall and Pt . Hacking sea temperatures from 1943 to 1960 ( Figure 1 middle panel ) and I put it in a file and looked at it every decade or so . I ’ ve always felt that it came from the CSIRO Divisions of Cloud Physics or Radiophysics , but I cannot be sure . To pay tribute to whomever made the plot , I thought it would be good to try to check it out .
The Sydney rainfall data are , of course , regular and plentiful . The Pt . Hacking sea temperature data would have come from small boat trips out from the Cronulla labs to the 50m depth contour to take temperatures and water samples with reversing thermometers and Nansen bottles at 10m depth intervals down to the bottom . The Pt . Hacking “ station ” was repeated every few weeks and was initiated by David Rochford . It introduced quite a few young marine scientists to sea sickness .
Figure 1 . The original hand drawn plot ( middle panel ), with the computer generated versions above and below .