Article ID Journal Published Year Pages File Type
4451491 Atmospheric Research 2006 13 Pages PDF
Abstract

A UV-MFRSR instrument was used to measure the global and diffuse irradiances in 7 narrowband channels in the UV range 299.4, 304.4, 310.9, 317.3, 324.5, 331.3 and 367.4 nm at Gwangju (35°13′N 126°50′E), Korea. Spectral UV-AOD was retrieved using the Langley plot method for data collected from April 2002 to July 2004. Temporal variation of AOD at 367.4 nm (AOD367 nm) showed a maximum in June (0.95 ± 0.43) and a minimum in February (0.31 ± 0.14). Clear seasonal variation of AOD367 nm was observed with average values of 0.68 ± 0.29, 0.82 ± 0.41, 0.48 ± 0.22 and 0.42 ± 0.21 in spring, summer, fall and winter, respectively. Average Ångström exponents for the entire monitoring period were 3.35 ± 1.06 and 2.03 ± 0.75 in the UV (310.9∼367.4 nm) and UV-A (324.5∼367.4 nm) ranges, respectively. Seasonal variation of the Ångström exponent showed a maximum in spring and a minimum in summer. The lowest Ångström exponent in summer might be due to hygroscopic growth of particles under conditions of high relative humidity. UV-AOD changes under different atmospheric conditions were also analyzed. Long-range transported haze, Asian dust and BB events increased UV-AODs by 2∼3 times in comparison to cases involving no events. Uncertainty in retrieving spectral UV-AOD was also estimated to range between ± 0.218 at 304.4 nm and ± 0.135 at 367.4 nm. Major causes of uncertainty were total column ozone retrieval and extraterrestrial irradiance retrieval at shorter and longer wavelengths, respectively.

Related Topics
Physical Sciences and Engineering Earth and Planetary Sciences Atmospheric Science
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