The Arctic or polar front has long been recognized as a transport barrier for mid-latitude air masses travelling into the high Arctic. A measurement based identification of the polar dome is difficult due to the temporal and spatial variability and a lack of consistent measurements in the lower few kilometers of the Arctic. Particularly the climatological role of the dome as a transport boundary for pollution tracers has not yet been fully addressed on the basis of in-situ measurements.

Black carbon emissions are one of the Far North’s three main short-lived climate-forcing pollutants and pose a health threat to local citizens. Black carbon emissions from Arctic States alone accounts for 30% of Arctic warming. Black carbon is emitted from a number of sources including the burning of diesel fuel, on which Northern communities are especially dependent; wild fires; agricultural and solid waste burning; and residential wood combustion. Throughout the Arctic, there are significant knowledge gaps regarding local black carbon emissions and the risks to communities.

Exponential build-up of bromine in the polar troposphere is linked to severe multi-day ozone depletion events in springtime. Recent research suggests that the snowpack and aerosols are the main sources of bromine, but the exact mechanisms of, and conditions required for these 'bromine explosions' are not well understood. The proposed reactions require low pH to proceed. Snow is naturally acidic, but an additional source of snow acidification is the Arctic haze, springtime pollution transported to the polar regions from north-eastern Europe and Siberia.

Air pollutants in the Arctic have impacts on climate change, ecosystems, regional air quality, and human health. Rapid changes to and complex interactions within the Arctic environment due to climate change and socio-economic drivers mean that there is an urgent requirement to improve understanding of sources of Arctic air pollutants. Previous studies have identified significant deficiencies in model skill in simulating Arctic distributions of air pollutants, both at the surface and in the vertical profile.

Air pollution is the fifth leading health risk factor globally. Communities in Arctic nations may be exposed to high levels of ambient and household air pollution from local sources, as well as air pollution transported from other regions. Previous studies have assessed the burden of disease from fine particulate matter (PM_2.5) and ozone in Arctic communities as part of broader global or national assessments.

Deterioration of air quality of Arctic climate may be contributing to the accelerated rates of global warming perceived relative to the global annually averaged temperature increase. This paper confirms that biomass burning (BB) was indeed the source of the observed air pollution, studies the transport of the smoke into the Arctic, and presents an overview of the observations taken during the episode. Fire detections from the MODIS instruments aboard the Aqua and Terra satellites were used to estimate the BB emissions.

It is known that the optical properties of aerosols change with particle size and particle nature. Fine and coarse mode (sub and super micron) aerosol optical depth (AOD), average particle size, particle size distribution width, and refractive index are fundamental and robust aerosol parameters that, along with particle shape determine all 1^st and 2^nd order aerosol properties.

NETCARE (Network on Climate and Aerosols: Addressing Fundamental Uncertainties in Remote Canadian Environments) is a Canadian research network established four years ago. This talk will present an overview of the network, which has had research projects involving ground-, ship- and aircraft-based observations, alongside GCM and CTM modeling efforts. This talk will address in particular results from summertime observations when the open ocean becomes a more dominant element of the regional biogeochemical system.

Emissions of anthropogenic aerosols vary substantially over the globe and the short atmospheric residence time leads to a highly uneven radiative forcing distribution, both spatially and temporally. Regional aerosol radiative forcing can, nevertheless, exert a large influence on the temperature field away from the forcing region through changes in heat transport or the atmospheric or ocean circulation.

Emissions from gas flaring have rarely been considered in global/regional emission inventories [Amann et al., 2013; Huang et al., 2015; Huang and Fu, 2016]. Flaring is a widely used approach of discharging and disposing of gaseous and liquid hydrocarbons through combustion at oil and gas production sites including oil wells, gas wells, offshore oil and gas rigs and landfills. Black carbon plays a unique role in the Arctic climate system due to its multiple effects.