Highly resolved WRF-BEP/BEM simulations over Barcelona urban area with LCZ

Abstract

This study evaluates the performance of urban schemes integrated in the Weather Research and Forecasting model (WRF) using Local Climate Zones (LCZ) as land use classification. We applied two multi-layer urban schemes: 1) Building Effect Parameterization (BEP) and 2) Building Energy Model coupled with BEP (BEP + BEM), over the Metropolitan Area of Barcelona (MAB) at 1km2 horizontal resolution for July 2016. These two simulations were compared with observations and a standard WRF simulation (BULK approach). Corine Land Cover 2012 provides background information for the entire simulation domain, while the LCZ covers MAB classifying the land cover into 10 classes according to urban morphology and thermal properties.BULK and multi-layer urban scheme experiments present a similar general error trend: overestimation of relative humidity and planetary boundary layer height and underestimation of temperature. Although BEP has the best correlation with observations, this is the scheme with the highest value of bias and RMSE for temperature and relative humidity, in particular during the night/morning. On the other hand, BEP + BEM performed with the minimum RMSE associated for temperature and relative humidity in the entire domain. BEP + BEM has shown to be more sensitive than the other schemes over locations where the land use in the model grid differs to the real one, which is a common consequent limitation of horizontal model resolution. This study also suggests that depending on the synoptic condition the scheme accuracy on determining PBLH might change considerably.