UV Irradiance Monitoring and Effects of Aerosol Optical Depth on the Ground-Based Measurement of Ultraviolet Irradiance at Kwangju, Korea

摘要

Ground-based measurement of ultraviolet irradiances with UV-A and UV-B sensors was made at Kwangju (35.13°N, 126.53°E), Korea from June 1998 to June 2001. These sensors measure integrated global UV radiation in 280-315 nm and 315-400 nm wavelength range, respectively. Measurement outputs from the UV sensors were sampled at every 15 seconds interval and saved every minute as a mean value into a data logger. The results showed that monthly mean values of UV-A and UV-B irradiances were maximized at 75 W/m~2 and 1.7 W/m~2, respectively. Total atmospheric optical depth was determined by analyzing the total and diffuse solar irradiances measured by a collocated multifilter rotating shadowband radiometer. Aerosol optical depth for 415 nm was determined by subtracting the contribution by Rayleigh scattering from total optical depth. Hourly and daily mean values of ground-based UV-A and UV-B irradiances were analyzed to investigate the effects of total atmospheric aerosol amount on them, especially those of the Asian dust storm particles in the spring.