Fire in the Earth System
Fire is a key process in the Earth system as it relates to a diverse set of impacts including vulnerability of lives and property, air quality, and as a driver of CO2 emissions.
GFDL Research
GFDL is engaged in several activities related to the representation and impacts of fire in the Earth system. On the research side, we have several successful examples of application of observed fire emissions on air quality (e.g. Lin et al., 2017, Xie et al., 2020) as well as process level ecosystem representation of lightning and human induced fire emissions and suppression on the carbon cycle. GFDL’s daily fire model including multi-day and crown fires (Rabin et al., 2018; Ward et al., 2018) was implemented in GFDL’s coupled carbon-chemistry-climate Earth system Model (GFDL-ESM4.1; Dunne et al., 2020) contributing public data to the Sixth phase of the Coupled Model Intercomparison Project (CMIP6; Eyring et al., 2016) with application to attribution of 2019 Alaska fire extremes (Yu et al., 2020). On the model development side, we are implementing fire injection heights as a function of satellite derived fire radiative power to compare modeled and observed carbonaceous aerosols.
These efforts play critical roles in fulfilling NOAA’s mandates to understand and project both future climate and the influence of climate and biogeochemical change on humans, and to provide stewardship of the atmosphere and oceans, particularly in the context of carbon cycle and air quality, and their climate interactions.
Climate-chemistry-fire interactions and feedbacks
GFDL has conducted fundamental research into the role of fire in the coupled chemistry climate including investigating the role of biomass burning on in modulating ozone (Naik et al., 2007), overall oxidation state (Mao et al., 2013) and on nitrogen emissions, gas-aerosol-chemistry interactions and the resulting atmospheric composition, and deposition (Paulot et al., 2017). These efforts improve understanding of the interactions and feedbacks by integrating fire emissions in a comprehensive atmospheric composition and climate context.
Application of fire emissions to assess air quality
GFDL’s focus has been in better understanding the coupling between fire, weather and climate patterns, and air quality, and has conducted several studies to assess the role of fire on past air quality extremes. These simulations with our atmospheric chemistry model forced by historical sea surface temperatures and nudged with reanalysis systems are a powerful complement to historical air quality observations through the ability to provide mechanistic attribution and improve understanding of drivers of past events. Our studies have demonstrated, for example, that variability in biomass burning and associated hot and dry meteorological conditions contribute significantly to interannual variability of surface ozone (Lin et al., 2017) and particulate matter pollution (Xie et al., 2020) over the western United States in summer, and the contrasting roles of long range transport, stratospheric intrusion, and wildfire on surface ozone ( Zhang et al., 2020; Langford et al., 2021).
Process Representation of Fire within the GFDL Earth system model
For over two decades, GFDL has worked collaboratively with researchers at Princeton University to develop GFDL’s capacity in Fire, starting from an annual fire model incorporated in GFDLs third generation models (Crevoisier et al., 2007; Magi et al, 2012) and continuing advances in representation of crop, pasture, and non-agricultural burning on daily timescales (Rabin et al., 2015) with further work incorporating relatively intense multi-day and crown fire (Ward et al., 2016; Ward et al., 2018) culminating in GFDL’s 4th generation ESM4.1 (Dunne et al., 2020) participating in the Sixth Coupled Model Intercomparison Project (CMIP6) with data available through the Earth System Grid Federation ESGF.
Emerging Research Areas
GFDL is developing capabilities for fire carbonaceous aerosol and other chemical injection into the troposphere based on Fire radiative power led by Paul Ginoux, reconsideration of volatile biological organic carbon emission by Fabien Paulot, and other applications to extremes.
Research Highlights