Wildfires are receiving ever more media and public attention around the world, partly due to climate change increasing the likelihood of extreme weather. While warm and dry conditions increase the risk of fire, a source of ignition – usually lightning or through human activity – is also needed.
Wildfires are a significant source of atmospheric pollution, including carbon gases, volatile organic compounds and particulate matter, influencing global atmospheric composition and chemistry.
The Copernicus Atmosphere Monitoring Service (CAMS) uses near-real-time observations of the location and intensity of active wildfires to estimate the emissions of pollutants. This is done through its Global Fire Assimilation System (GFAS). This allows active fires to be monitored and their estimated emissions to be used in the CAMS forecasts to predict the transport of the resulting smoke in the atmosphere. The forecasts are used in air quality apps, to help people limit their exposure to pollution, and by policymakers and local authorities to manage the impact of fires.
Fire radiative power
Fire radiative power (FRP) is a measure of heat output from a fire and is related to how quickly fuel is being consumed. Observations come from satellite-based sensors which can detect the heat signal. CAMS uses these observations to estimate the intensity and related emissions of fires in near real time. Higher values of FRP correspond to higher values of wildfire emissions.
Transport of smoke pollution
The direct impact of wildfires on atmospheric composition is to reduce air quality as smoke is transported away the fire. Smoke pollution can be toxic and have serious long-term effects on health. CAMS monitors the transport of emissions as well as the composition, and can forecast the direction in which smoke will move. While the highest levels of atmospheric pollution occur close to a fire, some smoke constituents have a long photo-chemical lifetime which means that smoke pollution can be subject to long-range transport (at continental and inter-continental scales) and can potentially affect air quality thousands of kilometres from the fire.
The CAMS daily forecast of Biomass Burning Aerosol Optical Depth - which is a measure of how much sunlight is able to pass through the atmosphere - indicates the amount of particulate matter in wildfire smoke plumes.
Carbon monoxide (CO) has a lifetime of a few weeks in the atmosphere so is a good indicator of the transport of pollution, which can travel thousands of kilometres, even between continents. CO is a product of incomplete combustion and has a range of sources, but wildfire emissions can be the most significant.