Assessing the Surface Solar Radiation Budget in the WRF Model: A Spatiotemporal Analysis of the Bias and Its Causes

Abstract

Solar radiation plays a key role in the atmospheric system but its distribution throughout the atmosphere and at the surface is still very uncertain in atmospheric models, and further assessment is required. In this study, the shortwave downward total solar radiation flux (SWD) predicted by the Weather Research and Forecasting (WRF) Model at the surface is validated over Spain for a 10-yr period based on observations of a network of 52 radiometric stations. In addition to the traditional pointwise validation of modeled data, an original spatially continuous evaluation of the SWD bias is also conducted using a principal component analysis. Overall, WRF overestimates the mean observed SWD by 28.9 W m−2, while the bias of ERA-Interim, which provides initial and boundary conditions to WRF, is only 15.0 W m−2. An important part of the WRF SWD bias seems to be related to a very low cumulus cloud amount in the model and, possibly, a misrepresentation of the radiative impact of this type of cloud.

Evaluation of the WRF‐lake model over a highland freshwater lake in southwest China

“…Solar radiation is the driving force of momentum, heat, and water vapor fluxes between the atmosphere and the underlying surface. Radiation scheme has significant influence on model simulation results [ Ruiz‐Arias et al ., ]. Before evaluating model performance on lake surface temperature, four radiation parameterization schemes were performed at the Erhai Lake, which are Dudhia shortwave and rapid radiative transfer model longwave, National Center for Atmospheric Research Community Atmosphere Model shortwave and longwave [ Collins et al ., ], rapid radiative transfer model for general circulation model (RRMTG) shortwave and longwave [ Iacono and Nehrkorn , ], and New Goddard shortwave and longwave [ Chou and Suarez , ] radiation parameterization schemes.…”

Is the summer season losing potential for solar energy applications in South Africa?

“…The satellite application facility (SAF) on climate monitoring (CM), CM-SAF produced the surface solar radiation datasetHeliostat (SARAH); which provides a useful highresolution data set of incoming surface shortwave (SIS) for solar radiation studies. The use of this data set has become popular in the scientific community (Ruiz-Arias et al, 2016, Trentmann et al, 2016Badescu and Dumitrescu, 2013). The present study aims to assess long-term trends in SD and change detection using SIS over South Africa on a seasonal scale.…”

A critical evaluation of modeled solar irradiance over California for hydrologic and land surface modeling

“…In a similar study over Spain, WRF was evaluated to have large, positive biases, especially over a region of complex terrain with meteorology characterized by convective systems. These biases decreased when subgrid cloud amount was included in the radiation scheme [ Ruiz‐Arias et al ., ]. Others have examined WRF's Q si , but only for clear‐sky conditions, attributing errors to factors like aerosols [ Jimenez et al ., ; Zhong et al ., ].…”

“…Based on this study and Ruiz‐Arias et al . [] we suggest that the subgrid cloud be included in the radiation scheme when using WRF to study land surface processes.…”