Global Climatology of Fine Particulate Matter Concentrations Estimated from Remote-Sensed Aerosol Optical Depth

AARON VAN DONKELAAR(1), Randall V. Martin(1,2), Ralph Kahn(3) and Robert Levy(3)

(1) Dalhousie University, Halifax (2) Harvard-Smithsonian Center for Astrophysics, Cambridge (3) NASA Goddard Space Flight Center, Greenbelt

     Abstract Number: 16
     Last modified: September 24, 2009

Abstract
Chronic exposure to fine aerosol negatively impacts human health, yet long-term, ground-based measurements are rare for much of the world and often represent only small locales. Satellite-derived estimates of PM2.5 offer insight into global exposures of PM2.5 over large spatial and temporal domains. We develop a high-resolution (10 km by 10 km) global climatology of PM2.5 for 2001-2006 by combining Aerosol Optical Depth (AOD) from two satellite instruments (MODIS and MISR) with aerosol properties from the GEOS-Chem chemical transport model. We find significant agreement with coincident North American PM2.5 measurements (r=0.78, slope=1.02, n=1083) and non-coincident global measurements (r=0.75, slope=0.89, n=297). We estimate a 2-sigma PM2.5 climatology error of ±(4.5 ug/m3 or 40%, whichever is larger), by combining errors in satellite AOD and simulated vertical structure with simulated sampling bias. Satellite-derived PM2.5 estimates over eastern North America and western Europe are between 10-20 ug/m3. Parts of northern India and eastern China are found to have annual mean PM2.5 concentrations of 35-60 ug/m3 and 80-100 ug/m3, respectively, with 35% of the Asian population exposure exceeding the WHO Interim Target 1 of 35 ug/m3. The highest 10% of the eastern Asian PM2.5 trend between 2001-2006 averages +6.5 ug/m3/year.