Urban heat island features of southeast Australian towns

This study investigates the magnitude of the urban heat island (UHI) effect in four small towns, with populations of less than 10,000, and one large c ity, with a population of 3.02 million. All of the experiment sites are loc ated in southeast Australia. Several climatic variables were measured along automobile transects from rural locations through the centres of each sett lement. Some transects were repeated at different times of the day. A compa rison of long-term temperature records is made from independent sites at on e of the towns, and the influence of the UHI effect on the historical tempe rature record is discussed in a qualitative nature. The maximum UHI effect at the centre of a town over grass is related to population via a regressio n equation. The urban-rural temperature difference was found to increase wi th increasing population via the equation DeltaT(u-r(max)) =1.42 log(population)-2.09 The results are discussed in the context of investigations in Europe and No rth America, and it is suggested that Australian towns and cities are likel y to have smaller maximum UHI effects than are observed on the other two co ntinents, for settlements with the same population. The findings of this st udy have implications for the compilation of historical temperature records and the maintenance of observation networks, particularly for climate chan ge studies.