Abstract: Using solar radiation and conventional meteorological observation data from the Shenyang national meteorological station between 1993 and 2022,this study analyzes the changes in solar radiation and its relationship with meteorological factors in this region.The results show that both the annual total radiation and direct radiation in Shenyang have shown continuously increasing,with climate inclination rates of 237 MJ·m^-2·(10 a)^-1 and 349 MJ·m^-2·(10 a)^-1,respectively.The diffuse radiation is negatively correlated with both total radiation and direct radiation,with a climate inclination rate of -112 MJ·m^-2·(10 a)^-1.From 1993 to 2022,the total solar energy resource level in Shenyang increased from abundant to very abundant,and the direct radiation ratio level changed from high/medium to very high.Total radiation and direct radiation showed good correlations with sunshine percentage,relative humidity,and haze days at both annual and monthly scales.From 2013 to 2022,Shenyang had the highest sunshine percentage,lowest relative humidity,and fewest haze days during the 1993-2022 period.The combined effect of these three meteorological factors likely contributed to the significant increase in annual total radiation and direct radiation,and the decrease in diffuse radiation in Shenyang over the past decade.Multiple linear regression models were established using annual total radiation and monthly atmospheric transparency coefficient as dependent variables and the three meteorological factors as independent variables.The validation results of these models in both Shenyang and Chaoyang passed significance tests,with correlation coefficients between simulated and measured values of annual and monthly total radiation exceeding 0.654 and 0.965,respectively,and simulation accuracies exceeding 92% and 90%.

Key words: Solar energy resources, Sunshine percentage, Relative humidity, Haze days, Multiple linear regression