10.7
A centennial-scale climate-change anomaly over a small region
Harvey Stern, Bureau of Meteorology, Melbourne, Vic., Australia
A CENTENNIAL-SCALE CLIMATE-CHANGE ANOMALY OVER A SMALL REGION
In 1937, an extensive study was carried out by the then (Australian) Commonwealth Meteorologist (W. S. Watt) into the climate of the small south-east Australian State of Victoria. That study presented the climate means for rainfall, pressure, temperature and humidity at four of the State's major cities and 33 of its country centres for the period of record ended 1935.
Regarding this record as a "base", the present paper explores changes in mean annual temperature recorded in Victoria subsequent to 1935. The paper finds that, on average, a small decline in mean annual temperature (-0.07°C) has occurred in Watt's set of climate stations since 1935. This is made up of a change of -0.03°C in the mean annual minimum temperature and a change of -0.12°C in the mean annual maximum temperature.
Expanding the data base to include all Victorian stations with record lengths of at least ten years since, and prior to, the end of 1935 (68 locations), that conclusion is confirmed and strengthened with an average change in mean annual temperature of -0.07°C also being found. This is made up of a change of -0.02°C in the mean annual minimum temperature and a change of -0.12°C in the mean annual maximum temperature.
The fall in mean annual temperature is small and is not statistically significant. However, the finding is in contrast to the findings of similar works carried out for other regions of the globe, including other parts of Australia. It therefore provides observational support to the findings of climate modellers that one would anticipate global climate change to exhibit considerable spatial and temporal variability.
Session 10, IPCC TAR: Long-term Climate Variability and Change: Part 3 (Parallel with Joint Session J1)
Wednesday, 12 January 2000, 3:30 PM-5:30 PM
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