Characteristics of Solar Spectral Radiation in the Guangzhou District

Characteristics of the solar ultraviolet radiation, visible radiation (photosynthetically active radiation) and near infrared radiation are examined by using the data of solar spectral radiations (observed angle is 23°11′) observed in the period of 1985—1990 in the Guangzhou district. The result shows that the monthly amounts of the solar spectral radiations and the total radiation are larger in July—October every year. The monthly mean ratio of visible to total radiation is 47.3%, infrared to total is 45.6% and UV to total is 7.1%. Furthermore, some features of the variations of solar spectral radiations in clear sky and UV radiation in 1990 are also given in the paper. And, the correlations of spectral radiations to cloud amounts, insolation duration and other factors are analyzed and discussed.