Temperature differences among local climate zones established by mobile measurements in two central European cities

ABSTRACT: Air temperature in urban areas is strongly influenced by the properties of surface cover, material and structure, and by human activity. Stewart & Oke (2012) quantified these properties and used them to introduce the definition of local climate zones (LCZs). LCZs should express characteristic temperature regimes of local-scale areas, and are supposed to be generic; however, their link to characteristic temperatures needs to be established based on field measurements. We investigated the link between LCZs and temperature in the central European cities of Brno and Olomouc, which differ in topography, relief, urban morphology and city size. We delineated LCZs, applying a clearly defined algorithm that uses data on the physical properties of the environment. In the next step, we performed night-time mobile air temperature measurements, and examined the differences between and within the LCZs. The results show that during calm and clear weather, the order of LCZ temperature was LCZ 2 > 5 > 8 > 6 > 9 > A ≈ D in Brno and LCZ 2 > 5 > 8 ≈ 6 ≈ 9 > B > D in Olomouc. Temperature differences between LCZs, as well as their significance, were more pronounced in the larger of the 2 cities (Brno). Similarly, intra-class temperature variability was generally higher in the larger city, which has a more complex topography. Overall, this study supports the general LCZ temperature patterns and thus the validity of the concept of LCZs.