On the development of shipping emission models and their applications in global and local impact assessment

Abstract

An extended shipping emission model (STEAM) is presented that can be used to characterize shipping emissions at both global and local scales. The model considers each vessel independently, obtaining activity data via the Automatic Identification System (AIS). The technical characteristics of vessels are obtained via commercial databases. The challenge of AIS data sparsity in open-sea conditions has been addressed by adopting a shortest marine path regeneration method. Furthermore, the issue of missing technical information for ships has been resolved with an algorithm that searches for the most similar ship. The model developed can also be used to simulate future scenarios, and we simulated future shipping emissions in a ‘business as usual’ (BAU) scenario and in another future situation where global regulations are imposed to enforce the use of cleaner marine fuels. The BAU and future scenario emissions are used in a global impact assessment study to quantify the health and climate effects of the proposed regulation.

Emissions from private leisure boat fleets have been overlooked previously. A separate model for the methodical assessment of leisure boat emissions with temporal and spatial variability is presented and applied for the Baltic Sea. In addition to exhaust emissions, the release of water contaminants that result from the use of anti-fouling paints is also considered.

Finally, the local-scale impacts of shipping in the form of pollutant concentrations are investigated using Gaussian dispersion modelling. The Helsinki region is used as a case study in which shipping emissions are modelled in high resolution with an operational air quality modelling system. As a novelty, recent air quality measurement information is being used to facilitate continuous data assimilation and improve modelling accuracy.

The by-product of this thesis is a collection of marine emission modelling tools and an operational urban air quality modelling system, all of which are in active use and provide information to private citizens, researchers and decision makers alike.