How local climate zones influence urban air temperature: Measurements by bicycle in Dijon, France

This study analyses mobile measurements of urban temperatures in Dijon (eastern France) to quantify the influence of urban form on the micro-scale variability of air temperature. A route was ridden identically on 33 spring and summer evenings on a bike fitted out with measuring instruments (VeloClim). These evenings followed sunny calm days conducive to the formation of thermal contrasts and urban heat islands (UHIs). Two typologies, Corine Land Cover (CLC) and Local Climate Zones (LCZ), are used to assess the impact of urban form and land cover on air temperatures based on ANalysis Of VAriance (ANOVA). ANOVA is applied to the mean of runs to maximize the effect of surface states, and to each run individually to maximize the influence of weather conditions. The results show that both typologies prove relevant and complementary for studying the impact of vegetated and artificialized zones on urban temperature. Temperature variations on intra-urban scales are significantly modulated by urban form and land cover types. Vegetated areas are systematically cooler than impervious surfaces. Independently of meteorological conditions, urban form has a decisive influence on air temperature and each CLC or LCZ category has an original air temperature signature.