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Advisor(s)
Abstract(s)
.The research proposed herein seeks to improve solar irradiance magnitude and variability results produced by
the Weather Research and Forecasting (WRF) model using a novel offline coupling procedure (OCP). The OCP
includes simulations in clear sky conditions, where the effects from varying atmospheric composition depend on
the broadband clear sky model used, on cloud attenuation and on decomposition techniques to accurately separate the global irradiance into direct and diffuse components. Furthermore, shadowing and slope effects from
orographic features and other obstacles are included with much greater detail. Benefits of the offline coupling
procedure were quantified by comparison against local solar radiation measurements over a period of one year.
A baseline test to explore the different configuration options was implemented. It considers two aerosol databases, three broadband clear sky models, two cloud attenuation corrections based on clear sky index (either
global or by components) and four decomposition models. Given the amount of results from baseline tests, the
relative root-mean-square error (rRMSE) was used as the criterion to identify the most suitable OCP configuration, which was subsequently used in the performance analysis. The current baseline test comprises seven
sites selected from the Baseline Radiation Network (BSRN) in different terrain complexities and atmospheric
conditions. Statistical indicators associated with the annual global horizontal irradiance reveal that OCP improved WRF results by 88.4% in terms of the relative mean bias error (rMBE) and by 5.0% in the value of the
Nash-Sutcliffe efficiency (NSE). A standard OCP configuration to model global horizontal irradiance only is
proposed. The rMBE of annual hourly global horizontal irradiance oscillated between −3.6% and 3.9%, whilst
the NSE varied between 0.608 and 0.939. The analogous quantities for diffuse horizontal irradiance were
19.3% rMBE 4.6%
and
0.371 NSE 0.717
, while for direct normal irradiance
6.5% rMBE 23.2%
and
0.101 NSE 0.656.
Description
Keywords
Numerical weather prediction Broadband clear sky model Cloud attenuation Decomposition model Shadowing Aerosols
Citation
Publisher
Elsevier