Monitoring And Analysis Of Ship Emissions In Ningbo Zhoushan Port Area

In recent years,the impact of ship emissions on the atmospheric environment has gradually become one of the hot issues.Ship exhaust contains a large number of pollutants,which is an important factor affecting ambient air quality,human health and climate change.Due to the complexity of ship types and their operating conditions,people still have insufficient understanding of ship emission characteristics.The coast of the East China Sea is one of the regions with the most intensive shipping activities in the world,bringing together all kinds of domestic and international transport ships.As a large port with the largest cargo throughput in the world for 10 consecutive years,ship emissions from Ningbo Zhoushan port have an important impact on its regional atmospheric environment.In this study,Putuo District of Zhoushan is selected as the research site.The main ambient atmospheric gas and particulate pollutants are measured for a long time by using online instruments such as Single-Particle Soot Photometer and thermoelectric gas instrument,and the speed of each ship is obtained by using automatic identification system（AIS）.According to the backward trajectory,it can be divided into:（1）the period dominated by ship emission（summer monsoon,dominated by ships in full operation or berthing）;（2）In the period dominated by the influence of inland air flow（winter wind）,the observed data are compared with the analytical model.The results show that the emissions of sulfur dioxide（SO₂）,nitrogen oxides（NOx）and black carbon aerosol（BC）are related to high-speed ships,while carbon monoxide（CO）may be related to ships with lower running speed,and there is no significant correlation between total particulate matter（PM）and ship speed.The emission enhancement factor of main pollutants under cruise condition is about 1～4 times that under idle condition.The reanalysis model has good simulation for BC and CO pollutants in the observation site,but poor simulation for SO₂ and NOx.The model underestimates the concentration of NOx and overestimates the concentration of SO₂.Through the in-situ observation of ship emissions under the direct environmental background,the study provides an important reference for evaluating the ship emission inventory and provides an observation basis for the reanalysis model to improve the accuracy of simulation.