Distributed Modeling Of Daily Solar Radiation

Based on the previous researches, this thesis creates a distributed model of daily solar radiation with considering the effects of sky and earth surface. The distributed simulation of daily global solar radiation over heterogeneous surface in China is implemented using the DEM data at resolution of1km×1km, the NCEP re-analyzed sea level air pressure data and the daily measurement data at weather stations and radiation stations. The spatial distribution of daily global solar radiation in2001is mapped at resolution of1km×1km.The following works are completed in this thesis:1) A model of earth surface air pressure is established based on the hypsometric equation. The model coefficients are calibrated with the meteorological station measurement data and NCEP re-analysed sea level pressure datasets. Monthly average surface pressure and daily average surface pressure are simulated under this model. The validation result of the high density meteorological stations shows the average absolute error of monthly average air pressure is0.93hPa, the average absolute error of daily average air pressure is1.02hPa. The spatial distributions of monthly average surface pressure and daily average surface pressure of china in2001are mapped with the resolution of1Km*1Km.2) The computing scheme of three types of horizontal starting data, including daily extraterrestrial solar radiation, dry clean atmosphere radiation and wet clean atmosphere radiation, is established. The spatial distributions of three types of horizontal starting data in2001in China are mapped at the resolution of1km×1km. Comparative analysis is applied to the different starting data. Wet clean atmosphere radiation can reflect the macro-terrain effect on solar radiation comparatively, the spatial distribution more reasonable.3) The performance of six models for horizontal daily solar radiation estimation using different meteorological factors is comparatively analyzed. The analysis indicates that the two integrated models with the sunshine percentage as main variable, the diurnal temperature range as correction variable obtain the best performance, the model based on sunshine percentage has the best experiential coefficients stability with quite good precision the other three models based on the diurnal temperature range give the worst results. The model based on sunshine percentage, which has stable experiential coefficients and quite good precision, is finally adopted to map the spatial distribution of horizontal daily solar radiation in2001in China. 4) The computing scheme of three types of heterogeneous surface starting data, including solar radiation, dry clean atmosphere radiation and wet clean atmosphere radiation, is established. The spatial distributions of three types of heterogeneous surface starting data in2001are mapped at the resolution of1km×1km. Comparative analysis is applied to the different starting data.5) Based on three types of starting data including solar radiation, dry clean atmosphere radiation and wet clean atmosphere radiation, a distributed model of daily global solar radiation over heterogeneous surface is created. The spatial distributions of daily global solar radiation over heterogeneous surface in2001in China are mapped at the resolution of1km×1km. Similar pixel method validation, Mean Absolute Bias Error is1.709MJ/m2and Mean Absolute Relative Bias Error is15.22%, shows the distributed model has a good simulation.This thesis has the following innovations comparing to the previous researches:1) With consideration of the effect on the earth surface air pressure by altitude and air temperature, a precise experimental statistical model with specific physical meanings is established based on the hypsometric equation. The spatial distribution of earth surface air pressure is mapped with high precision and high resolution.2) Fully taking into account the effect on the radiation transmission by various of atmosphere factors, the daily global solar radiation is calculated with different starting data including extraterrestrial solar radiation, dry clean atmosphere radiation and wet clean atmosphere radiation. This thesis has more plentiful starting data than previous researches.3) Six statistical models belonging to three types are compared. More meteorological factors’application in estimation models of solar radiation is analyzed.