Evaluation of the Influence of Marine Vessel Emissions Plumes on Measurements Collected at the Amphitrite Point Coastal Background Site

Abstract:

A marine boundary layer air quality monitoring site was established on the west coast of Vancouver Island at Amphitrite Point in May 2010. The main objectives for the site were to (1) determine background air pollutant concentrations and trends, (2) support air quality modelling validation and development, (3) complement the high elevation background monitoring site at Whistler and other regional monitoring initiatives, and (4) conduct chemical process studies in the marine boundary layer. During the initial evaluations of the collected data (e.g., O₃, PM_2.5, NO_x, and SO₂) and its comparison to other marine background sites, periods were observed that are clearly representative of background air, continental background air, and those clearly influenced by ship and boat traffic in the region.

On the basis that the individual pollutants observed are closely related to emissions observed by underway marine vessels, certain observational periods in the collected dataset were associated with ship plumes. Utilizing the data provided by marine vessel movements, CALPUFF emission inputs were generated for dispersion modelling of ship pollutants. CALPUFF model output data were subsequently compared to measured data in order to better characterize impacts from marine vessel traffic.