Uncertainty assessment of solar irradiances at two baseline surface radiance Network (BSRN) stations

Based on the method proposed by Qiu et al. (2014), some improvements for cloud screening have been developed to calibrate short-wave direct and global solar irradiances (DSI and GSI)[1]. This calibration at two Baseline Surface Radiation Network (BSRN) stations, Izana of Spain during 2010-2013 and Carpentras of France during 2005-2013, are analyzed in this paper. The transfer coefficients of DSI and GSI are used to represent the irradiances divided by the world Radiation Reference (WRR). They are higher than 1 in summer and lower than 1 in winter at two stations. The uncertainty of DSI and GSI is also assessed and it is coincident with 3% and 6% uncertainties for direct and global measurements [2].