Study of Urban Heat Islands Using Different Urban Canopy Models and Identification Methods

This work aims to compare the performance of single‑(SLUCM) and multilayer (BEP-Building effect parameterization) urban canopy models (UCMs) coupled with Weather Research Forecasting model (WRF), along application two heat island (UHI) identification methods. The methods are: (1) “classic method”, based on temperature difference between rural areas; (2) “local method” at each location when land use is considered urban, it replaced by dominant category surroundings. study performed as a case for city Lisbon, Portugal, during record-breaking August 2003 heatwave event. Two main differences were found in UHI intensity (UHII) spatial distribution methods: reduction half UHII nighttime using local method; dipole signal daytime pattern classic method, associated sheltering provided high topography northern part city, that reduces advective cooling lower areas under prevalent wind conditions. These results highlight importance method modeling studies fully isolate regional geographic contributions distribution. Considerable improvements obtained near‑surface representation coupling WRF UCMs but better SLUCM. over most densely urbanized BEP, which can be linked its larger nocturnal turbulent kinetic energy (TKE) near surface negative sensible (SH) fluxes. latter may skin possibly owing SH fluxes surface. Due higher TKE, BEP significantly overestimates planetary boundary layer height compared SLUCM observations from soundings. comparison previous Lisbon shows simulation heavily rely number vertical levels within canopy.