Objective classification of Australian climates

Köppen’s scheme to classify world climates was devised in 1918 by Dr Wladimir Köppen of the University of Graz in Austria (Köppen 1931; Köppen and Geiger 1928, 1930-39). This paper presents a modification of Köppen’s scheme. The Köppen classification is based on the concept that native vegetation is the best expression of climate, climate zone boundaries having been selected with vegetation limits in mind (Trewartha 1943). The classification may be applied to present-day climatic conditions. Alternatively, it also may be used to develop a future climatology that is implied by the output of a numerical climate model (Löhmann et al. 1993) – although the reliability of such a future climatology would be dependent upon the reliability of the numerical climate model output. Köppen recognises five principal groups of world climates that are intended to correspond with five principal vegetation groups. These five climatic groups may be described as tropical rainy, dry, temperate rainy, cold snowy forest, and polar. The dry climates are defined on the basis of there being an excess of evaporation over precipitation (which is determined from the mean annual temperature and the mean annual rainfall). The tropical rainy Aust. Met. Mag. 49 (2000) 87-96