Estimating Ground-Level PM2.5 in China Using Aerosol Optical Depth Determined from the GOCI Satellite Instrument

Tuesday, 16 December 2014: 11:35 AM
Junwei Xu1, Randall Martin1, Jhoon Kim2, Myungje Choi2, Qiang Zhang3, Guannan Geng3, Yang Liu4, Zongwei Ma4, Lei Huang5 and Yuxuan Wang3, (1)Dalhousie University, Halifax, NS, Canada, (2)Yonsei University, Seoul, South Korea, (3)Tsinghua University, Beijing, China, (4)Emory University, Atlanta, GA, United States, (5)Nanjing University, School of the Environment, Nanjing, China
The severe air pollution in China imposes a pressing need to monitor fine aerosol concentration (PM2.5) at fine temporal and spatial resolutions. Satellite remote sensing is emerging as a key solution to this need. GOCI is the first satellite remote sensor that is able to provide multi-spectral aerosol optical properties in Northeast Asia on an hourly basis. We implemented a set of filters to minimize cloud contamination in GOCI aerosol optical depths (AOD). Evaluation of filtered GOCI AOD by AERONET AOD data at three sites in China indicates significant agreement (hourly RMSE=0.03-0.16). A global chemical transport model (GEOS-Chem) is used to relate total column AOD to near-surface PM2.5. The simulated PM2.5/AOD ratio generally captures the seasonal variation in ground measurements. We assess the relationship of a full year of GOCI-derived PM2.5 concentrations versus ground measurements at more than 800 locations across China, and found significant agreement (r=0.86, slope=0.8), indicating GOCI is a promising tool to provide in-depth and accurate data for air quality studies in Northeast Asia.