Airborne lidar measurements of aerosol and ozone above the Canadian oil sands region

Abstract

Abstract. Aircraft-based lidar measurements of atmospheric aerosol and ozone were conducted to study air pollution from the oil sands extraction industry in northern Alberta. Significant amounts of aerosol were observed in the polluted air within the surface boundary layer, up to heights of 1 to 1.6 km above ground. The ozone mixing ratio measured in the polluted boundary layer air directly above the oil sands industry was equal to or less than the background ozone mixing ratio. On one of the flights, the lidar measurements detected a layer of forest fire smoke above the surface boundary layer in which the ozone mixing ratio was substantially greater than the background. Measurements of the linear depolarization ratio in the aerosol backscatter were obtained with a ground-based lidar and this aided in the discrimination between the separate emission sources from industry and forest fires. The retrieval of ozone abundance from the lidar measurements required the development of a method to account for the interference from the substantial aerosol content within the polluted boundary layer.

A fully autonomous ozone, aerosol and nighttime water vapor lidar: a synergistic approach to profiling the atmosphere in the Canadian oil sands region

“…14b coincident with the ozone as well as the depolarization ratio plot in Fig. 14c, showing a value of about 5 %, consistent with other smoke plume measurements (Aggarwal et al, 2018).…”

“…Ozone is a short-lived climate pollutant (SLCP) and air pollutant that can have detrimental impacts on human health (Malley et al, 2015;Lippmann, 1991), agriculture (McKee, 1994) and ecosystems (Ashmore, 2005) when present at high enough concentrations. Tropospheric ozone is photochemically produced primarily from nitrogen oxides and volatile organic compounds (VOCs) from anthropogenic sources, is biogenically produced from forest fires (Aggarwal et al, 2018;Trickl et al, 2015) and can be enhanced through stratospheric/tropospheric transport (STT) events (Ancellet et al, 1991;Langford et al, 1996;Leblanc et al, 2011;Stohl and Trickl, 1999). Both of these latter sources can have significant impacts on ozone concentration although typically their impacts vary within the vertical distribution of the troposphere.…”

Validation of MAX-DOAS retrievals of aerosol extinction, SO<sub>2</sub>, and NO<sub>2</sub> through comparison with lidar, sun photometer, active DOAS, and aircraft measurements in the Athabasca oil sands region

“…High concentrations of SO 2 and other pollutants over the AOSR have prompted measurements using aircraft studies (Baray et al, 2018;Gordon et al, 2015;Liggio et al, 2016Liggio et al, , 2019Simpson et al, 2010), in situ measurements (Amiri et al, 2018;Hsu, 2013;Tokarek et al, 2018), sun photometers (Fioletov et al, 2016), and satellites (McLinden et al, 2012(McLinden et al, , 2014(McLinden et al, , 2016. Long-term monitoring through satellite measurements is an attractive choice due to the large scale of the operations.…”

Validation of MAX-DOAS retrievals of aerosol extinction, SO<sub>2</sub> and NO<sub>2</sub> through comparison with lidar, sun photometer, Active-DOAS and aircraft measurements in the Athabasca Oil Sands Region

“…S-ratios were modelled using Mie scattering theory and measurements of surface-level particle composition and size distribution at Fort McKay South for various times during Aug 23 to determine temporal variability in the S-ratio. Source code for the Mie scatting calculations can be found in (Aggarwal et al, 2018).…”