Ayodeji Akingunola's research while affiliated with Environment Canada and other places

... Another aspect is the calculation of AOD and aerosol properties, which can vary from model to model. Recent studies (e.g., Majdzadeh et al., 2022) have discussed and proposed new approaches to calculate aerosol properties which could improve the accuracy of the reported AODs from the model. ...

... For example, it has been recently shown that TROPOMI is able to detect short-lived species such as HONO in fresh wildfire plumes (Theys et al., 2020). So far, most fire-related studies based on TROPOMI observations were based on the aerosol, CO and NO 2 atmospheric data products, with a focus on inferring information on plume transport (Johnson et al., 2021), NO x emissions and lifetime (Griffin et al., 2021;Jin et al., 2021), and on the impact of fires on the carbon cycle and the radiative budget (e.g., Byrne et al., 2021;Li et al., 2020;Magro et al., 2021;van der Velde, van der Werf, Houweling, Maasakkers, et al., 2021). In contrast, little has been done to exploit the TROPOMI HCHO and CHOCHO observations in the context of fires, despite their potential to inform on VOC emissions (e.g., Cao et al., 2018;Fu et al., 2008;Stavrakou et al., 2009). ...

... Weather conditions affect aerosols' optical and radiative properties (Makar et al., 2015(Makar et al., , 2021Mao et al., 2018). In this work, 90 the effect of weather on aerosol optical properties can be quantified using the data from the horizontal lidar and weather monitors. ...

... For instance, Ražnjević et al. (2022) have employed large-eddy-simulation (LES) modelling driven by reanalysis data for interpreting field observations of CH 4 . Further, model simulations of tracer transport and dispersion have been previously used for assessing the uncertainties/errors in top-down retrievals and optimizing the observational approach (Conley et al., 2017;Fathi, 2017;Angevine et al., 2020;Fathi et al., 2021;. Numerical model simulations can also be used for simulating ground-45 based and/or airborne observations, where model generated fields are used as a proxy for measurement data (virtual sampling). ...

... SASKTRAN-derived box-AMF profiles have been used by Griffin et al. (Griffin et al., 2019, 2021 from Environment and 365 Climate Change Canada (ECCC) to analyze TROPOMI measurements over North America. The first application compared TROPOMI data with in-situ aircraft, in-situ ground-based, and remote ground-based NO 2 measurements over the Canadian oil sands, improving agreement through use of regional, higher density retrieval inputs. ...

... The LCS data from the roadside location (LCS4) show significantly lower precision than those at the urban background site, as seen in the B-A plot. This could be caused by differences in particle properties and size distributions between the two sites (Gramsch et al., 2021), and by the high frequency variation of transport emissions close to the roadside site and turbulence effects (Baldauf et al., 2009;Makar et al., 2021). Duplicate measurements show that all sensors of this type responded similarly in this roadside environment (not shown here), supporting the high internal consistency of this device but indicating a spatial heterogeneity in some key error sources. ...

... This gives a total LAI of 1.17 at the site. We compare this measured value to LAI from MODIS-derived seasonal LAI maps at 2.5 km resolution (Zhang et al, 2021). The site location is near the edge of two 2.5 km grid cells (see supporting figure S1) with 175 values of 1.09 and 1.27 in January and 1.89 and 2.23 in July. ...

... LFG releases to the atmosphere will disperse to the height of the boundary layer. Hourly estimates of boundary layer height (H in m) at each landfill, for the date and time of each visit, were extracted from the GEM-MACH model [35][36][37]. Occasionally, this model predicted very low heights; these low values were increased to 100 m and referred to as the adjusted boundary layer height H adj . ...

... LFG releases to the atmosphere will disperse to the height of the boundary layer. Hourly estimates of boundary layer height (H in m) at each landfill, for the date and time of each visit, were extracted from the GEM-MACH model [35][36][37]. Occasionally, this model predicted very low heights; these low values were increased to 100 m and referred to as the adjusted boundary layer height H adj . ...

... The negative bias is primarily caused by the impact of the high surface reflectance in the O 2 A band, which affects aerosol retrievals. A similar comparison for the 2018 biomass burning fires in North America (Griffin et al., 2020) indicates that this bias also strongly depends on the thickness of the smoke plume. They reported a −2.1 km bias of ALH for thin smoke plumes, which is reduced to only ∼ −0.7 km for plumes thicker than 1.5 km. ...