Impacts of an intense wildfire smoke episode on surface radiation, energy and carbon fluxes in southwestern British Columbia, Canada

Abstract

Abstract. A short, but severe, wildfire smoke episode in July 2015, with an aerosol optical depth (AOD) approaching 9, is shown to strongly impact radiation budgets across four distinct land-use types (forest, field, urban and wetland). At three of the sites, impacts on the energy balance are also apparent, while the event also appears to elicit an ecosystem response with respect to carbon fluxes at the wetland and a forested site. Greatest impacts on radiation and energy budgets were observed at the forested site where the role of canopy architecture and the complex physiological responses to an increase in diffuse radiation were most important. At the forest site, the arrival of smoke reduced both sensible and latent heat flux substantially but also lowered sensible heat flux more than the latent heat flux. With widespread standing water, and little physiological control on evapotranspiration, the impacts on the partitioning of turbulent fluxes were modest at the wetland compared to the physiologically dominated fluxes at the forested site. Despite the short duration and singular nature of the event, there was some evidence of a diffuse radiation fertilization effect when AOD was near or below 2. With lighter smoke, both the wetland and forested site appeared to show enhanced photosynthetic activity (a greater sink for carbon dioxide). However, with dense smoke, the forested site was a strong carbon source. Given the extensive forest cover in the Pacific Northwest and the growing importance of forest fires in the region, these results suggest that wildfire aerosol during the growing season potentially plays an important role in the regional ecosystem response to smoke and ultimately the carbon budget of the region.

Smoke from 2020 United States wildfires responsible for substantial solar energy forecast errors

“…However, due to the smoke plumes persistent over the region during 7, 8, 10, and 11 September, solar power production was reduced compared to typical conditions by approximately 10%-30% during peak production hours (here considered 19-23 UTC or 12-16 Pacific Daylight Time (PDT)). Our findings agree well with those from previous studies focused on wildfire smoke impacts on solar reduction [22,36], including during the 2020 season in the Western U.S. [20,61]. In contrast, 9 September and the 12-16 September period featured solar production much closer to what is expected under typical conditions (less than 7% reduction) because the smoke plumes were transported out of the region.…”

Emission of trace gases and aerosols from biomass burning – an updated assessment

“…d Sum of chemically identified and unidentified species, from online updates to Akagi et al (2011). involving transport times and reaction rates of the species concerned. Because of their large spatial and temporal coverage, such measurements are quite valuable, and I have therefore included some of them in this assessment, as long as they were either dealing with long-lived species or used appropriate correction methods (i.e., chemistry-transport model calculations to correct for atmospheric transformations) (Rinsland et al, 2007;Mebust et al, 2011;Tereszchuk et al, 2011Tereszchuk et al, , 2013Schreier et al, 2015;Viatte et al, 2015;Lutsch et al, 2016;Adams et al, 2019). They can be compared with in situ measurement results by referring to the original data in the Supplement spreadsheet.…”

Wildfire‐Smoke Aerosols Lead to Increased Light Use Efficiency Among Agricultural and Restored Wetland Land Uses in California's Central Valley

“…A short‐lived smoke event over southwestern British Columbia resulted in changes to the surface energy budget and some evidence of productivity enhancements in a bog ecosystem. At the same time, productivity decreased in a nearby coastal forest, although smoke density varied between the two sites (McKendry et al, ). Finally, an observational study in the Amazon rainforest found that under moderate, but not intense aerosol optical depths, diffuse fraction enhanced productivity (Yamasoe et al, ).…”