Evaluation of MM5, WRF and TRAMPER meteorology over the complex terrain of the Po Valley, Italy

The objective of this study was to evaluate three meteorological models (MM5, WRF and TRAMPER) by comparing the calculated meteorological parameters with observations over the Po Valley area (Italy) for 2005. The analysis shows that MM5 and WRF perform with similar quality, with advantages of WRF at following high resolution time patterns and better scores of MM5 at reproducing annual averages, noticed for precipitation and relative humidity calculations. Results from the TRAMPER model also reflect very well surface meteorological measurements, they may be however driven by data assimilation applied in this modelling system and thus strongly influenced by very local effects. This feature of TRAMPER may lead as well to large uncertainties in reproducing other parameters important for air quality modelling such as planetary boundary layer (PBL) heights, friction velocity (u*) values or stability conditions.