An improved gridded polycyclic aromatic hydrocarbon emission inventory for the lower reaches of the Yangtze River Delta region from 2001 to 2015 using satellite data

An improved gridded polycyclic aromatic hydrocarbon (PAH) emission inventory for the lower reaches of the Yangtze River Delta (YRD) region from 2001 to 2015 was developed using satellite data. Despite rapid increases in energy consumption, the annual total emissions of the 16 PAHs showed overall decreasing trends, from a maximum of 5445 t in 2001 to a minimum of 2619 t in 2015, with the largest decline (84.6%) observed in the residential sector. Different spatial allocation methods used in gridded PAH emission inventories have substantial influences on the distributions of PAHs; therefore, we improved the accuracy of the spatial allocation of industrial and open biomass burning PAH emissions using various satellite data. The gridded secondary and tertiary industrial GDP (GDP23) calculated using corrected nighttime light data was the best spatial proxy for the spatial allocation of industrial PAH emissions in the YRD region. We generated a gridded burned area for 2001-2015 by coupling the MCD64A1 and MCD14ML fire products, which was used to allocate PAH emissions from open biomass burning. Finally, we found that changes in the spatial distribution of PAH emissions were mainly driven by energy consumption and degree of technological advancement in different regions during 2001-2015.