Evaluating urban-rural climate representation in Europe in REMO-TEB convection-permitting climate simulations

The development of convection-permitting regional climate model (CPRCM) simulations allow us to resolve urban areas and their climatic phenomena in contrast to their rural surroundings. However, with increasing resolution, the complex terrain and characteristics of cities must be adequately represented. The EU Horizon project Impetus4Change (https://impetus4change.eu) aims to improve the quality, accessibility and usability of near-term climate information and services at local to regional scales. The project utilises dynamically downscaled regional climate models (RCMs) to produce simulations at 3km resolution for urban areas across Europe. To achieve this, we integrate the Town Energy Balance model (TEB; Masson, 2000), a single-layer urban canopy model, into the RCM REMO to simulate urban climates and urban-rural interactions.

Compared to a previously bulk urban form in REMO, TEB introduces distinctive urban features, such as an urban canyon with roofs, walls and roads. This allows for a more realistic representation of vertical radiative trapping and turbulent exchange. The double-nested CPRCM simulations performed include evaluation simulations driven by reanalysis (ERA5.1) for 2000-2009 and historical simulations driven by the general climate model MPI-ESM1-2-HR for 1995-2014, covering two large domains across Northern and Southern Europe. The output is compared to observations and existing 3 km and 12.5 km simulations of REMO without a sophisticated urban canyon scheme to assess the added value of more realistic urban climate representations in Europe.

*This project has received funding from the European Union’s Horizon Europe research and innovation programme under grant agreement No 101081555

Reference
Masson, V. A Physically-Based Scheme For The Urban Energy Budget In Atmospheric Models. Boundary-Layer Meteorology 94, 357–397 (2000). https://doi.org/10.1023/A:1002463829265