Aerosol optical properties over urban and industrial region of Northeast China by using ground-based sun-photometer measurement

The special and temporal characteristics of aerosol optical depth (AOD) and Angstrom exponent (Alpha) were analyzed by using the data from a CE318 sun-photometer at Shenyang, Anshan, Benxi and Fushun in urban and industrial region of northeastern China. The high AODs over Shenyang and Fushun occurred in the summer and winter with two peaks. In contrast, the monthly averaged AODs at Anshan and Benxi have a single peak distribution. The AOD frequency distribution at Shenyang and Benxi can be well fit by a bi-modal normal distribution with r2 = 0.94 and 0.91. The AOD frequency distribution at Anshan and Fushun have identical peak value at approximately 0.40. The seasonal AOD at Benxi is larger than the other three stations, and the seasonal Alpha at Shenyang is the largest of all stations followed by Anshan, Fushun and Benxi. An analysis of the AOD and Alpha scatterplots suggests that the aerosol size in Shenyang, Anshan, Benxi and Fushun can be affected by both fine and coarse particles.