Source area definition for local climate zones studies. A systematic review.

Abstract The correct contextualisation of urban measurements is one of the challenges that urban climate researchers have been dealing with for decades. The Local Climate Zones scheme (LCZs) emerges as a system for characterising these measurements from the thermal perspective. The rapid embracing of the LCZs by researchers from many disciplines, altogether with its adoption for other purposes such as planning, has led to an inexistent or, at its best, flexible use of the source area definition. This practice might call into question the contextualisation of many measurements, highlighting the imperative need to shed light on the source area methods within the urban context. In this study, a systematic review is conducted to compile previous experiences in which the source area was applied in the built environment. Results obtained from the systematic search are summarized and presented according to three scales: the inertial sublayer, the roughness sublayer, and the urban canopy layer. These previous experiences are studied according to their methodological contribution to the source area definition, emphasizing those studies that have considered this concept altogether with the LCZ scheme. This review aims at promoting the knowledge about footprint methodologies and its correct application within the LCZs. Highlights • The source area definition within urban contexts was systematically reviewed. • Differences in the footprint adoption are related with the atmospheric scale. • The embracement of the source area by LCZ studies is low and very heterogeneous. • Choosing, estimating and reporting the source area should be standardised. • Further research is needed to develop reliable footprint tools within the UCL. [ABSTRACT FROM AUTHOR]