Accuracy assessment of water vapor and cloud attenuation estimated from ERA5 single level parameters at two sites with large difference of altitude

Abstract

ERAS reanalysis provides meteorological parameters that can help to predict atmospheric propagation effects. We investigate the accuracy of using ERA5 single level parameters, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$TCWV$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$TCLW$</tex> , to calculate water vapor and cloud attenuation, respectively, in El Alto (4065 m.a.s.l, Bolivia) and Madrid (633 m.a.s.l, Spain), locations having different climatological conditions. The assessment is performed using as reference the attenuation predicted by physical models combined with atmospheric vertical profiles from radiosondes: 4 years (El Alto) and 8 years (Madrid). The most recent global prediction models from ITU-R are also implemented to complete testing analysis: P.676-12 and P.804-8 global maps based methods. The results obtained show that water vapour attenuation from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$TCWV$</tex> predict statistics than can be used with small errors. Cloud attenuation from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$TCLW$</tex> show large discrepancies in El Alto. However, in Madrid, good agreement with RAOBS-based statistics is observed when using Salonen08 Tunned model as cloud detection model.