An AIS-based high-resolution ship emission inventory and its uncertainty in Pearl River Delta region, China.

Ship emissions contribute significantly to air pollution and impose health risks to residents along the coastal area. By using the refined data from the Automatic Identification System (AIS), this study developed a highly resolved ship emission inventory for the Pearl River Delta (PRD) region, China, home to three of ten busiest ports in the world. The region-wide SO2, NOX, CO, PM10, PM2.5, and VOC emissions in 2013 were estimated to be 61,484, 103,717, 10,599, 7155, 6605, and 4195t, respectively. Ocean going vessels were the largest contributors of the total emissions, followed by coastal vessels and river vessels. In terms of ship type, container ship was the leading contributor, followed by conventional cargo ship, dry bulk carrier, fishing ship, and oil tanker. These five ship types accounted for >90% of total emissions. The spatial distributions of emissions revealed that the key emission hot spots all concentrated within the newly proposed emission control area (ECA) and ship emissions within ECA covered >80% of total ship emissions in the PRD, highlighting the importance of ECA in emissions reduction in the PRD. The uncertainties of emission estimates of pollutants were quantified, with lower bounds of -24.5% to -21.2% and upper bounds of 28.6% to 33.3% at 95% confidence intervals. The lower uncertainties in this study highlighted the powerfulness of AIS data in improving ship emission estimates. The AIS-based bottom-up methodology can be used for developing and upgrading ship emission inventory and formulating effective control measures on ship emissions in other port regions wherever possible.

Spatial and Seasonal Dynamics of Ship Emissions over the Yangtze River Delta and East China Sea and Their Potential Environmental Influence.

The Yangtze River Delta (YRD) port cluster is one of five major port clusters in China and is home to Shanghai port, the largest port worldwide. In this study, an automatic identification system-based model was built to estimate the ship exhaust emissions in the YRD and the East China Sea within 400 km of the coastline. In 2010, the total emissions of SO2, NOX, and PM2.5 were 3.8 × 10(5) tonnes/yr, 7.1 × 10(5) tonnes/yr, and 5.1 × 10(4) tonnes/yr, respectively. More than 60% and 85% of the ship emissions occurred within 100 km and 200 km of the coastline, respectively. Ship emissions also showed distinct seasonal variability. The emission of SO2 and NOX by ships in hot spots, such as ports and vessel traffic hubs was much higher than that on land, with maximum SO2 and NOX intensities from ships that were 36 times and 17 times greater, respectively, than the maximal land-based emissions. The potential impact of ship emissions at six hot spots on the surrounding atmospheric environment was estimated with the HYSPLIT model. Our study demonstrated that ship emissions have an important impact on both the entire YRD region and on greater East China.