Evaluation of Ship Emission Intensity and the Inaccuracy of the Steam Model

Abstract

To assess the impact of ship emission on the environment, it is imperative to establish a reliable approach to estimate the amount of pollutants emitted by ships. The temporal, spatial and voluminal emission intensity of CO2, NOX, CO, NMVOC, PM2.5 and SO2 are investigated using the STEAM (Ship Traffic Emission Assessment Model) model. Then, the inaccuracy of the STEAM model is evaluated by calculating the emission fluctuations at switch points between different operation modes. The results revealed that ship speed could significantly affect the temporal, spatial and voluminal emission intensities of ships. Compared to temporal and voluminal emission, the intensity of spatial emission increases dramatically when the speed is close to 0. In addition, it was also shown that the STEAM model induces an inaccuracy whenever the ship changes the operation mode. The research results provide guidance to plan the operation and management strategies to reduce pollutants emitted from ships.

Keywords: STEAM model, ship emission, voluminal emission intensity, model inaccuracy, AIS data