Sensitivity analysis of atmospheric spectral irradiance model

¹ Institute of Earth Sciences, University of Évora, Évora, Portugal
² Science Engineer Laboratory for Energy (LabSIPE), National School of Applied Sciences, University of Chouaib Doukkali, El Jadida, Morocco
³ Energy Laboratory, Solar Energy Unit National Laboratory of Energy and Geology, Lisbon, Portugal

^* e-mail: aalbino@uevora.pt

Received: 13 May 2019
Received in final form: 29 August 2019
Accepted: 10 December 2019
Published online: 17 January 2020

Abstract

Many Radiative Transfer Models (RTM) have been developed to simulate and estimate solar irradiance. Theirs accuracy is well documents in literature nonetheless the effect of the parameters uncertainties on the established models has not been well studied yet. This work focuses on implementing a RTM based on the models found in the literature along with some updates, with the aim to study the sensitivity of the model towards the variations of the input parameters. The parameters studied in this paper are: the day of the year, the solar zenith angle, the local atmospheric pressure, the local temperature, the relative humidity, the height of ozone layer concentration, the ozone concentration, the single scattering albedo, the ground albedo, the Ångström’s exponent and the aerosol optical depth. The sensibility analysis is achieved using the Normalized Root Mean Square Error (NRMSE) as an independent function, calculated with a set of simulated measurements of spectral global solar irradiance and a reference spectrum generated with a group of standard input parameters.