Evaluation of COSMO simulations with TERRA-URB scheme and ECOCLIMAP-SG land use dataset over Warsaw agglomeration

The impacts of global climate change make cities increasingly vulnerable to environmental challenges, leading to the need for accurate weather forecasts to support various societal functions and ensure public safety. Regional weather and climate models have often employed simplified representations of urban environments, which can lead to inaccuracies in forecasting key meteorological variables such as temperature, humidity, wind, and precipitation within these complex regions. The increasing spatial resolution of the models demands more sophisticated and detailed descriptions of urban surfaces and microphysical processes to capture the unique interactions between the built environment and the atmosphere. This work examines recent advancements in urban parameterisation within the Consortium for Small-scale Modeling (COSMO), specifically focusing on incorporating Local Climate Zones (LCZs) using ECOCLIMAP-SG land use data for the TERRA-URB urban scheme.
In the frame of this study, the methodology for elaborating the new lookup tables will be presented as necessary for implementing ECOCLIMAP-SG and integrating LCZ-specific parameters during the preprocessing steps. The set of the COSMO model simulations at the sub-kilometre scale for Warsaw agglomeration is carried out to justify the added value of using the urban scheme and ECOCLIMAP-SG dataset. The simulation results are compared with meteorological measurements from the surface stations at an hourly resolution. The investigated period covers a heat wave case at the end of June and the beginning of July 2022. The evaluation is performed considering the dependence of the model performance on lead time 48 hours ahead, separately for urban and rural stations. Additionally, spatial verification is conducted to study the model's ability to capture urban effects.