High-latitude wildfires, atmospheric composition, and climate

Abstract

In high-latitude regions, larger and more frequent fires have been occurring over recent years, a tendency that is expected to continue in the coming decades due to warmer temperatures and regionally decreased precipitation imposed by climate change (IPCC,2019). Boreal wildfires in general are a significant source of CO2 emissions, as well as other greenhouse gases and aerosols (Akagi et al. 2011; Van Der Werf et al. 2010), e.g. emissions from boreal forests between 1997 and 2016 accounted for 7.4% of the global emissions (van der Werf et al. 2017). The effects of boreal fires on future climate have not been investigated and are potentially of great importance since climate change is occurring more rapidly in those high-latitude areas. More flammable forests in addition to the large carbon-rich peatlands, will potentially lead to devastating consequences.The overall goal of our project is to quantify the effects of high-latitude wildfire emissions on atmospheric composition as well as climate. For this purpose, simulations with the EC Earth Earth System Model (ESM) are being employed to characterize the past, present and future variability and changes of wildfires especially in high latitudes. In the results presented here, we demonstrate how the EC Earth model performs when forced with prescribed fire emissions (GFED4) and with a more detailed peat fire module developed by our team. The mean state, seasonality, and interannual variability of fire emissions and key atmospheric constituent abundances (black carbon, organic carbon, NOx, CO, ozone, amongst others) are validated in the model, using a range of observational datasets. This validation exercise is a key step before employing the EC-Earth model for quantifying future impacts of high-latitude fires on atmospheric composition and climate. IPCC,2019: Jia, G., E. Shevliakova, P. Artaxo, N. De Noblet-Ducoudré, R. Houghton, J. House, K. Kitajima, C. Lennard, A. Popp, A. Sirin, R. Sukumar, L. Verchot, 2019: Land–climate interactions. In: Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems [P.R. Shukla, J. Skea, E. Calvo Buendia, V. Masson-Delmotte, H.-O. Pörtner, D.C. Roberts, P. Zhai, R. Slade, S. Connors, R. van Diemen, M. Ferrat, E. Haughey, S. Luz, S. Neogi, M. Pathak, J. Petzold, J. Portugal Pereira, P. Vyas, E. Huntley, K. Kissick, M, Belkacemi, J. Malley, (eds.)]. In press.Akagi, S.K. et al., 2011: Emission factors for open and domestic biomass burning for use in atmospheric models. Atmos. Chem. Phys., 11, 4039–4072, doi:10.5194/acp-11-4039-2011.Van Der Werf, G.R. et al., 2010: Global fire emissions and the contribution of deforestation, savanna, forest, agricultural, and peat fires (1997–2009). Atmos. Chem. Phys., 10, 11707–11735, doi:10.5194/acp-10-11707-2010.Van Der Werf, G.R. et al., 2010: Global fire emissions and the contribution of deforestation, savanna, forest, agricultural, and peat fires (1997–2009). Atmos. Chem. Phys., 10, 11707–11735, doi:10.5194/acp-10-11707-2010.