Aerosol absorption optical depth of fine-mode mineral dust in eastern China

• Published in: Atmospheric and oceanic science letters = Daqi-he-haiyang-kexue-kuaibao 2016-01, Vol.9 (1), p.7-14
• Main Authors: Zhang, Tian-Hang, Liao, Hong
• Format: Article
• Language: English
• Subjects: AAOD; Absorption; Aerosols; Atmospheric particulates; Black carbon; Dust; Dust storms; Earth; eastern China; Fine-mode; mineral dust; Optical analysis; Organic carbon; Spring; Winter; 中国东部; 光学厚度; 吸收; 大气监测网; 气溶胶; 矿物粉尘; 细颗粒; 辐射强迫
• ISSN: 1674-2834; 2376-6123
• DOI: 10.1080/16742834.2015.1126154

The fine-mode aerosol absorption optical depth (AAOD) retrieved from the Aerosol Robotic Network (AERONET) has been used in previous studies to calculate the radiative forcing of black carbon (BC) aerosol, assuming that the absorption by fine-mode aerosols (diameter ≤ 1 μm) is primarily from BC while the absorption by larger particles (diameter > 1 μm) is principally from dust. In the present study, the Community Earth System Model was used to simulate and quantify the contribution of fine-mode dust to fine-mode AAOD in eastern China (29-41°N, 104-122°E)-an area where concentrations of BC are high. The simulated fine-mode dust concentrations were constrained by observations from nine sites belonging to the Chinese Meteorological Administration Atmosphere Watch Network. Averaged over eastern China, the simulated annual mean fine-mode dust AAOD was 3.6 × 10 −3 , with the maximum AAOD in spring and the minimum value in winter. The contribution of fine-mode dust to the total fine-mode AAOD (sum of fine-mode dust, BC, and organic carbon) in winter, spring, summer, and autumn was 3.4%, 25.2%, 12.5%, and 14.9%, respectively, with an annual mean value of 15.1%. The results indicate the importance of removing fine dust AAOD when the AERONET fine-mode AAOD is used for calculating the radiative forcing of BC in eastern China.