Evaluation of WRF shortwave radiation parameterizations in predicting Global Horizontal Irradiance in Greece. (February 2016)

• Record Type: Journal Article
• Authors: Zempila, Melina-Maria; Giannaros, Theodore M.; Bais, Alkiviadis; Melas, Dimitris; Kazantzidis, Andreas
• Is Part Of: Renewable energy. Volume 86(2016)
• Page Start: 831
• Page End: 840
• Publication Date: 2016-02
• Subjects: Global Horizontal Irradiance -- Numerical modeling -- WRF -- Shortwave radiation parameterizations -- Hellenic Network of Solar Energy -- Aerosol effects; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2015.08.057
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: This study aims at assessing the differences induced in the Global Horizontal Irradiance (GHI) predictions by the mesoscale atmospheric Weather Research and Forecasting (WRF) model when using different shortwave radiation. Model predictions are compared with GHI measurements at 12 stations of the Hellenic Network of Solar Energy (HNSE) for January, April, July and October 2013. The shortwave radiation schemes that were evaluated are: the Dudhia, the updated Rapid Radiative Transfer Model (RRTMG), the updated Goddard and the Goddard Fluid Dynamics Laboratory (GFDL) schemes. All schemes perform better under cloudless conditions due to limited ability of the WRF model to simulate cloudy conditions. The Dudhia scheme performs best with mean relative difference of 2.2 ± 15% for clear-skies, while the differences for the other schemes range between 5 and 12% with similar standard deviations. For all-skies, the model-derived hourly GHI is overestimated for all schemes (∼40–70%). For the daily averages, the model predictions are in better agreement with the measurements, mainly under all-sky conditions, with deviations of about half those of the hourly data and smaller standard deviations. There are strong indications that the differences of the model predictions from the measurements depend on the solar zenith angle and the amount of aerosols at each station. Highlights: We evaluate 4 shortwave radiation schemes of WRF model in terms of GHI. A dependence on solar zenith angle was found for all schemes. The Dudhia scheme performs best especially during clear-sky conditions. The model daily averaged predictions are in better agreement with the measurements. A correlation was found in model-to-measurement GHI ratios with AOD.