Atmospheric Pollution in Coastal Environments
Aldona Wiacek, Li Li, Keane Tobin, Julia Purcell
Saint Mary's University, Department of Environmental Science
As part of a new research program dedicated to understanding atmospheric composition, we have initiated measurements of marine boundary layer trace gases using the active technique of Open-Path Fourier Transform Infrared Spectroscopy (OP-FTIR). The recently acquired system (2015) significantly expands the measurement capability of atmospheric trace gases in Halifax and in Atlantic Canada, and a long-term marine boundary layer composition observatory is being designed to house the instrument. To date, we have conducted field campaigns in Halifax Harbour, on SMU campus, near traffic emission sources, as well as in coastal forest, indoor and wildfire-influenced environments. Trace gas concentrations are derived from atmospheric absorption spectra recorded over one-way atmospheric open paths ranging from 30-500 m. The retrieval process is being optimized to target greenhouse gases (CO2, CH4, N2O), ozone and its precursors (CO, NOx and many VOCs), trace gases implicated in particle formation (SO2, HNO3, NH3), and other IR-active species permanently imprinted in stored absorption spectra. First results from field measurements in Halifax harbour in Jul/Aug 2016 will be presented, with some discussion of changing levels of atmospheric pollution due to changing marine fuel sulfur content regulations.