LONG-TERM AND RECENT ANOMALOUS TEMPERATURE-CHANGES IN AUSTRALIA

Temperature records from rural station networks are being assembled and analyzed for many Northern Hemispheric locations. In this study, we examine the annual mean, maximum, and minimum temperatures from a network of rural stations in Australia over the period 1911-1990. Our findings show general cooling from 1911 to 1978 with a steady decrease in the diurnal temperature range. The cooling in the mean temperature results from a decrease in maximum temperature that is larger than the increase in minimum temperature. However, in the late 1970s, maximum, minimum, and mean temperatures all rose sharply, although the daily temperature range continued its steady decline. This discontinuity in the Australian temperature record is similar in magnitude and timing to discontinuities found in the Northern Hemispheric climate system. Whether it is related to the buildup of greenhouse gases or some other cause, is unknown.