Attribution of aerosol light absorption to black carbon and volatile aerosols

作者：Shrestha Rijana; Kim Sang Woo^*; Yoon Soon Chang; Kim Ji Hyoung

来源：Environmental Monitoring and Assessment, 2014, 186(8): 4743-4751.

DOI：10.1007/s10661-014-3734-5

• Black carbon
• Volatile aerosols
• Filter-based optical instruments
• Aethalometer
• Light absorption

We investigated the contribution of volatile aerosols in light-absorption measurement by three filter-based optical instruments [aethalometer, continuous light-absorption photometer (CLAP), and continuous soot monitoring system (COSMOS)] at Gosan Climate Observatory (GCO) from February to June 2012. The aerosol absorption coefficient (sigma (abs)) and the equivalent black carbon (BC) mass concentration (M (BC)) measured by the aethalometer and CLAP showed good agreement with a difference of 9 %, which is likely due to the instrumental uncertainty. However, sigma (abs) and M (BC) measured by the COSMOS with a heated inlet were found to be approximately 44 and 49 % lower than those measured by the aethalometer and CLAP under ambient conditions, respectively. This difference can be attributed to the light absorption by the volatile aerosols coexisting with the BC. Even considering inherent observational uncertainty, it suggests that approximately 35-40 % difference in the sigma (abs) and M (BC) can be contributed by volatile aerosols. Increase in the difference of M (BC) measured by the aethalometer and COSMOS with the increasing thermal organic carbon (OC) measured by Sunset OC/EC analyzer further suggests that the filter-based optical instruments without the use of a heater are likely to enhance the value of sigma (abs) and M (BC), because this sample air may contain both BC and volatile aerosols.

• 出版日期2014-8