Sensitivity of near-surface meteorology to PBL schemes in WRF simulations in a port-industrial area with complex terrain

Parameterizations of the Planetary Boundary Layer (PBL) embedded in numerical weather prediction models are crucial in the simulation of local meteorology and require a special investigation. In this study we evaluate simulations at 1 km horizontal resolution using six PBL schemes of the Weather Research and Forecasting model (WRF) by comparison to observations performed in a coastal port-industrial area (Civitavecchia) on the Tyrrhenian coast of Central Italy. During the measurement campaign (April 2016) three types of atmospheric circulation regimes were identified: breeze, jet and synoptic. Some generalizations can be inferred from the results, despite the variety of settings analyzed (two sites, three regimes in both day and night conditions). Our results show that the temperature simulation is much more sensitive to the configuration at night than during the day, especially on breeze days, when the occurrence of stable boundary layer is favored. For wind speed, nonlocal schemes are very similar to each other, unlike the local closure schemes. The use of the urban Building Environment Parameterization (BEP) significantly improves the simulation of the 2 m temperature during the jet evenings and nights, while it entails a further overestimation of the temperature during the breeze days leading to a reduction of the bias.

Automated summary

This study evaluated simulations at 1 km horizontal resolution using six PBL schemes of the WRF model by comparison to observations in a coastal port-industrial area in Central Italy. The results show that temperature simulations are more sensitive to nighttime configurations, nonlocal schemes have similar wind speed performance, and the urban BEP significantly improves temperature simulation in certain conditions.