Air quality monitoring in communities of the Canadian Arctic during the high shipping season with a focus on local and marine pollution

Abstract

Abstract. The Canadian Arctic has experienced decreasing sea ice extent and increasing shipping activity in recent decades. While there are economic incentives to develop resources in the north, there are environmental concerns that increasing marine traffic will contribute to declining air quality in northern communities. In an effort to characterize the relative impact of shipping on air quality in the north, two monitoring stations have been installed in Cape Dorset and Resolute, Nunavut, and have been operational since 1 June 2013. The impact of shipping and other sources of emissions on NO x , O 3 , SO 2 , BC, and PM 2.5 pollution have been characterized for the 2013 shipping season from 1 June to 1 November. In addition, a high-resolution Air Quality Health Index (AQHI) for both sites was computed. Shipping consistently increased O 3 mixing ratio and PM 2.5 concentration. The 90 % confidence interval for mean difference in O 3 mixing ratio between ship-and no shipinfluenced air masses were up to 4.6-4.7 ppb and 2.5-2.7 ppb for Cape Dorset and Resolute, respectively. The same intervals for PM 2.5 concentrations were up to 1.8-1.9 µg m −3 and 0.5-0.6 µg m −3 . Ship-influenced air masses consistently exhibited an increase of 0.1 to 0.3 in the high-resolution AQHI compared to no ship-influenced air masses. Trajectory cluster analysis in combination with ship traffic tracking provided an estimated range for percent ship contribution to NO x , O 3 , SO 2 , and PM 2.5 that were 12.9-17.5 %, 16.2-18.1 %, 16.9-18.3 %, and 19.5-31.7 % for Cape Dorset and 1.0-7.2 %, 2.9-4.8 %, 5.5-10.0 %, and 6.5-7.2 % for Resolute during the 2013 shipping season. Additional measurements in Resolute suggested that percent ship contribution to black carbon was 4.3-9.8 % and that black carbon constituted 1.3-9.7 % of total PM 2.5 mass in ship plumes. Continued air quality monitoring in the above sites for future shipping seasons will improve the statistics in our analysis and characterize repeating seasonal patterns in air quality due to shipping, local pollution, and long-range transport.

Continuous light absorption photometer for long-term studies

“…The CLAP has proven to be a reliable instrument for determining the aerosol light absorption coefficient under a wide variety of sampling conditions, including from research aircraft (Aliabadi et al, 2015;Backman et al, 2016;Sherman et al, 2015;Schmeisser et al, 2017;Sinha et al, 2017;Sorribas et al, 2017). The two-part design, with the associated need to separate the two halves for each filter change, has been mostly problem-free.…”

Particulate trimethylamine in the summertime Canadian high Arctic lower troposphere

“…Furthermore, seabird colonies were located close to the ice edge in Lancaster Sound and are likely a source of ammonia (Wentworth et al, 2016). Anthropogenic emissions might have affected our measurements, but are mainly related to the sparse Arctic settlements (Aliabadi et al, 2015) and can be ruled out by comparison with other tracers (e.g., CO). We can therefore expect that our observations from 4-12 July 2014 were mainly influenced by Arctic marine and terrestrial emissions.…”

Characterization and Parametrization of Reynolds Stress and Turbulent Heat Flux in the Stably-Stratified Lower Arctic Troposphere Using Aircraft Measurements

“…Due to lack of a diurnal cycle in the Arctic, turbulent quantities should be independent of the diurnal period and can be plotted versus normalized height (normalized by the boundarylayer height) or a stability parameter such as the gradient Richardson number (Ri) to provide characteristics of the troposphere during the polar day under more general conditions (Aliabadi et al 2015). Figure 7 gives the vertical variation in stability parameter (Ri), indicating increasing stability with altitude.…”