A sensitivity analysis of the WRF model to shortwave radiation schemes for air quality purposes and evaluation with observational data

Abstract

Shortwave radiation is a key meteorological component influencing formation and destruction of many atmospheric pollutants, most of all tropospheric ozone. It is the main driver of photochemical reactions, affects surface temperature and enhances biogenic VOC production. Because uncertainties in meteorological fields provided by meteorological models highly affect chemical transport model simulations, accurate information on spatial and temporal variability of shortwave radiation is needed for reliable air quality modeling. The main aim of this study is to assess the meteorological model performance in representing observational data. In this study, the Weather Research and Forecasting (WRF) model is applied to the area of Lower Silesia, Poland, in order to test three shortwave radiation schemes: Goddard, RRTMG and GFDL scheme. The test period is a high ozone episode of 17.06-04.07.2008. Simulations were run with different shortwave radiation options, while all other physics parameterizations remained constant. The results were then evaluated based on radiation measurements conducted in the Observatory of the Department of Climatology and Atmosphere Protection in Wroclaw, Poland. There are some discrepancies between the employed parameterizations both in terms of quality of the results and computational costs but in general, all schemes applied show reasonable consistency with observations.