Surface clear-sky shortwave radiative closure intercomparisons in the Weather Research and Forecasting model

The models were forced using measurements of precipitable water and aerosol optical properties from five AERONET sites and were evaluated against high-quality observations of GHI, DNI, and DIF at four nearby or coincident sites of the SURFRAD network and one at the Atmospheric Radiation Measurement Central Facility in the contiguous US.

In addition, the performance has been intercompared against the Dudhia broadband SW parameterization together with a regressive model to calculate DNI and DIF and the top-class SMARTS2 SW spectral model. The role of aerosols has been investigated by running the models with and without aerosols. All of them have shown outstanding skill at predicting GHI within the range of the expected observational error, regardless of whether aerosol information is provided as input.