Assessing the impact of shipping emissions on air pollution in the Canadian Arctic and northern regions: current and future modelled scenarios

Abstract

Abstract.A first regional assessment of the impact of shipping emissions on air pollution in the Canadian Arctic and 15 northern regions was conducted in this study. Model simulations were carried out on a limited-area domain (at 15-km horizontal resolution) centred over the Canadian Arctic, using the Environment and Climate Change Canada's on-line air quality forecast model (GEM-MACH), to investigate the contribution from the marine shipping emissions over the Canadian Arctic waters (at both present and projected future levels) to ambient concentrations of criteria pollutants (O 3 , PM 2.5 , NO 2 , and SO 2 ), atmospheric deposition of sulphur and nitrogen, atmospheric loading and deposition of black carbon in the Arctic. 20Several model upgrades were introduced for this study, including the treatment of sea-ice in the dry deposition parameterization, chemical lateral boundary conditions, and the inclusion of North American wildfire emissions. The model is shown to have similar skills in predicting ambient O 3 and PM 2.5 concentrations in the Canadian Arctic and northern regions as the current operational air quality forecast models in North America and Europe. In particular, the model is able to simulate well the observed O 3 and PM components at the Canadian high Arctic site, Alert. The model assessment shows that, 25 at the current (2010) level, Arctic shipping emissions contribute to less than 1% of ambient O 3 concentration over the eastern Canadian Arctic and between 1 and 5% of ambient PM 2.5 concentration over the shipping channels. Arctic shipping emissions make a much greater contributions to the ambient NO 2 and SO 2 concentrations, at 10 -50% and 20 -100 %, respectively. At the projected 2030 business-as-usual (BAU) level, the impact of Arctic shipping emissions is predicted to increase to up to 5% in ambient O 3 concentration over a broad region of the Canadian Arctic and to 5 -20% in ambient 30 PM 2.5 concentration over the shipping channels. In contrast, if emission controls such as the ones implemented in the current North American Emission Control Area (NA ECA) are to be put in place over the Canadian Arctic waters, the impact of shipping to ambient criteria pollutants would be significantly reduced. For example, with NA-ECA-like controls, the 2 shipping contributions to population-weighted concentration of SO 2 and PM 2.5 would be brought down to below the current level. The contribution of Canadian Arctic shipping to the atmospheric deposition of sulphur and nitrogen is small at the current level, < 5%, but is expected to increase to up to 20% for sulphur and 50% for nitrogen under the 2030 BAU scenario.At the current level, Canadian Arctic shipping also makes only small contributions to BC column loading and BC deposition, < 0.1% on average and up to 2% locally over eastern Canadian Arctic for the former, and between 0.1 and 0.5% over the 5 shipping channels for the latter. The impacts are again predicted to increase at the projected 2030 BAU level particularly over the Baffin Island and Baf...

The 13th and 14th Workshops on Antarctic Meteorology and Climate

“…At the 2019 WAMC, a presentation of Antarctic WRF forecast results highlighted needs to address: (1) model clouds and microphysics; (2) surface temperature warm biases; and (3) the representation of diurnal temperature cycles. Another presentation illustrated the use of special measurements from the 2015−16 ARM (Atmospheric Radiation Measurement Program) West Antarctic Radiation Experiment to reveal a liquid water deficit in clouds in AMPS WRF forecasts, leading to the cloud radiative effect being too small (Hines et al, 2019).…”

Climatic Responses to Future Trans‐Arctic Shipping

“…Lastly, an increase in atmospheric particulates that serve as CCN will tend to increase cloud albedo by encouraging formation of smaller and more numerous cloud droplets (Twomey, 1977), particularly in liquid clouds (Christensen et al, 2014; Morrison et al, 2012). Although the influence of particulate emissions in the Arctic has historically been small and localized relative to more populous lower latitudes (Gong et al, 2018; Peters et al, 2011), increases in shipping emissions could substantially raise CCN, enhance cloud formation, and induce a climatic response (Mueller, 2018; Wang et al, 2013; Yang et al, 2018). …”