Wildfires have become increasingly frequent and intense in recent years, resulting in significant environmental and health implications. Beyond the immediate damage caused by flames, wildfires also release substantial amounts of pollutants into the atmosphere, which can have far-reaching consequences for atmospheric composition, air quality, and climate change. Carbon monoxide (CO), a colorless and odorless gas, is one of the prominent pollutants released during wildfires. CO plays a crucial role in the atmospheric chemistry. It affects the oxidizing capacity of the atmosphere, influences the lifetime of other gases such as methane (CH₄), which is a potent greenhouse gas, and contributes to the formation of harmful air pollutants such as tropospheric ozone (O₃).
TROPOMI, the state-of-the-art satellite instrument aboard the European Space Agency’s Sentinel-5 Precursor satellite, plays a critical role in monitoring atmospheric composition, including emissions from wildfires. TROPOMI measures the solar radiation reflected by the Earth’s surface and atmosphere in various spectral ranges. Its high spatial resolution and sensitivity allow it to detect carbon monoxide and other atmospheric gases as well as aerosols, thereby providing valuable data on the distribution and transport of pollutants released during wildfire events. By analyzing TROPOMI data, we can study the distribution of carbon monoxide, its transport patterns, and its interaction with other atmospheric constituents. The satellite observations provide essential input for atmospheric models that simulate the atmospheric chemistry and help assess the influence of wildfire emissions on air quality and climate change. The data can aid in the development of mitigation strategies, early warning systems, and policies for managing wildfires and reducing their impact on the atmosphere.
Canada experiences significant wildfires each year, particularly in its boreal forest regions. The 2023 wildfire season is especially notable, with record-breaking fires that emitted large amounts of carbon monoxide across vast regions. The animation above shows carbon monoxide measured by TROPOMI throughout the summer of 2023. It illustrates how CO is released from various wildfires across the Northern hemisphere and how it then travels around the globe. A prominent example are the Canadian fires in May and June 2023, whose emissions traveled over the Atlantic and reached Southern Scandinavia for example on 25 May 2023 (see image below). During that day aerosol observations at the Birkenes observatory in East Agder showed enhanced levels.
Total column carbon monoxide (in units of mol per square meter) observed by the TROPOMI instrument on the Sentinel-5P platform for 2023-05-25.
