Standardizing thermal contrast among local climate zones at a continental scale: Implications for cool neighborhoods

Abstract

The Local Climate Zone (LCZ) classification system provides a standardized framework to differentiate neighbor-hoods for intra-city heat island studies. Yet the thermal contrast of air temperatures over different LCZs has not been examined at a continental scale. Using ground-based meteorological observations in 2016, here we investigated the seasonal thermal behaviors of various LCZs over China. Measured air temperatures over studied LCZs are found to have strong relations with latitude, altitude, and the distance to coastline. Thermal contrasts reduce to less than 1 degrees C in all seasons after removing the signal of background mean air temperature determined by geographical conditions. Despite the air temperature variation within individual LCZs, results reveal consistent characteristic air temperature regimes of LCZs exist at a continental scale. The warmth of built type LCZs is more evident at night, with an annual mean air temperature difference of 0.51 degrees C compared to the low plant LCZ. Among the studied LCZs, compact mid-rise neighborhoods have consistently high air temperatures throughout the year. Comparative analysis suggests that open high-rise neighborhoods are preferred over compact mid-rise and low-rise neighborhoods for sustainable city development. Our results provide useful guidance for landscape design and planning to create cool cities and neighborhoods.