The modified layer-by-layer weakening solar radiation models based on relative humidity and air quality index

Air pollution has a significant weakening effect on solar radiation. Therefore, it is important for the development and utilization of solar energy to establish a solar radiation model under the influence of fog and haze. Based on the analysis of existing layer-by-layer weakening solar radiation models, the discontinuous meteorological data provided by MODIS satellite are replaced by continuous measured data from meteorological stations. The beam solar radiation model and diffuse solar radiation model are modified by using relative humidity (φ) and air quality index (AQI). The results show that the correction effects of these modified models are better. The R value of beam solar radiation models have increased by 5.74%, the R value of diffuse solar radiation models have increased by 41.27%, and other statistical parameters (RSE, RMSE and NSE) have also been improved to a certain extent. The calculated value of the modified models is closer to the measured data. In addition, the order of correction parameters also has an effect on the results. The research shows that the best correction effect is to use relative humidity first and then AQI. According to this method, the layer-by-layer weakening solar radiation models can be more accurate and reliable.