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Marine Vessel Emission Inventory Tool


Methods to estimate ship emissions continue to evolve, driven by growing concern about hazardous air pollutants and the need to quantify GHG contributions associated with port and marine vessel activities.

Over the last 20 years, computing power and the availability of detailed vessel data have increased significantly, allowing for improvements to marine vessel emission inventories. These improvements include linking of Automatic Identification System (AIS) vessel traffic data to individual vessel characteristics that classification societies compile. This approach allows emissions to be estimated for individual vessel movements, which can be spatially allocated using geographic information systems (GIS). This approach also provides for better quantification of engine load by comparing the vessel’s actual speed to its maximum speed using the propeller law. AIS data are reported every few seconds, so temporal elements can also be better quantified.

Ports have a growing interest in developing refined emission inventories that more accurately characterize their emissions and help clarify a port’s regional contribution or help prioritize emission reduction initiatives. These interests revolve around all emission sources, including marine vessels, drayage trucks, cargo-handling equipment, locomotives, and stationary point sources such as prime and back up electric generation units, incinerators, boilers, and vessel maintenance facilities.

Other mobile sources have software tools for estimating emissions (e.g., the EPA MOVES model for highway vehicles and nonroad equipment, and the Federal Aviation Administration’s Aviation Environmental Design Tool). These software tools allow for standardization in data collection, easy updating of fuel and emission factors, and development of emission estimates of similar quality to those from other agencies using the same tool.


Development of software tools for estimating emissions for ports, regulatory agencies, and ship operators. This tools will include a database of internationally peer-reviewed emission factors and hazardous air pollution (HAP) speciation profiles to ensure that the latest and most representative factors are used. Furthermore, the tool will be able to use AIS vessel traffic and vessel specific attributes to quantify power ratings, and maximum design speed to estimate kW-hrs and calculate propulsion loads (note that the propeller law does not apply to towing vessels and that load defaults would need to be developed). The software will also allow inclusion of generic data for smaller vessels, such as tugs and towboats for which detailed attributes may not be available. The tool will also account for compliance with domestic and international exhaust and fuel standards.


Emission inventories are critical for policy makers, regulatory agencies, non-governmental organizations, and port authorities when assessing emissions, evaluating compliance with State Implementation Plan (SIP) targets, meeting regulatory requirements, and prioritizing emission reduction strategies. Having a software tool that can be easily updated with the latest vessel activity, emission factors, and HAP speciation profiles ensures that the appropriate data are used consistently by staff across agencies who develop marine vessel inventory data.

The spatial and temporal resolution of marine emissions that can be realized through the use of AIS data can allow users to identify pollution events or hot spot locations associated with port and marine vessel activities. The resulting emissions can be used to inform work products associated with the national emission inventory, state SIPs, and regional/local clean air strategies.

These inventories are increasingly important for building the relationship between ports and communities living nearby, as well.

Related Research:

· Results from this work could be fed into regional fate and transport models to estimate the impacts of ship emissions on human and ecosystem health

· Results from this work could be combined with models of open-loop scrubber effluent to estimate potential for acidification


The following tasks are not comprehensive. They are intended as a guide to what might be necessary to successfully complete the research:

Phase 1

· Compile and review available marine vessel emission inventory methodologies, emission factors, load factors, HAP speciation profiles, vessel attributes, AIS data and GIS shapefiles that can be used to accurately estimate emissions.

· Identify likely users for this software tool

· Meet with stakeholders to assess available data, required surrogates, and useful output.

· Map out data flow that integrates data inputs into an algorithm that provides fuel usage and emission outputs

Phase 2

· Develop and populate data modules for the software tool

· Link the data modules in the emission inventory software tool

· As a test case, run the tool using available data from an existing port inventory.

· Compare software output with existing port inventory output.

· Make necessary adjustment to the software

· Develop documentation

Phase 3

Prepare implementation manual and PowerPoint presentation for dissemination to potential users/ stakeholders


One of the most challenging aspects of this project will be determining a source for the vessel characteristics data, generally such data comes from classification societies such as Lloyd’s or IHS . As it is proprietary, there are limitations to how the data can be incorporated into a non-commercial public model. Without the use of classification society data or something similar, the input would be less accurate resulting in inventories that may not be an improvement.


This model would be relevant to agencies such as. IMO, MARAD, the U.S. EPA, Bureau of Ocean Energy Managements, local and state agencies, non-governmental groups, trade groups such as the American Association of Port Authorities as well as consultants and vessel operators. The tool would be a particularly useful for smaller ports unable to conduct their own inventories.

Sponsoring Committee:AW030, Marine Environment
Research Period:Longer than 36 months
Research Priority:High
RNS Developer:Richard Billings, Ed Carr, Thomas Jelenic, Timothy Sturtz, and Christina Wolfe
Source Info:AIS data from USCG, Marine Traffic, ExactEarth or similar. Ship-level data from Lloyds/IHS.
Date Posted:12/22/2017
Date Modified:01/05/2018
Index Terms:Ships, Air pollution, Pollutants, Emissions inventory,
Cosponsoring Committees: 
Marine Transportation
Vehicles and Equipment

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