Large Enhancements in Southern Hemisphere Satellite‐Observed Trace Gases Due to the 2019/2020 Australian Wildfires

Abstract

Vegetation fires occur regularly in Australia between the months of August and December (Giglio et al., 2013;van der Werf et al., 2017). Burning activity predominantly occurs in northern Australia, but is widespread across the continent (Andela et al., 2017). Giglio et al. (2013) suggested that the majority of vegetation fires take place on savanna and shrubland, but in south-eastern Australia forest fires are most prevalent (Bradstock et al., 2012; van der Werf et al., 2010). Over recent decades, there have been largescale decreases in Australian fire activity (Andela et al., 2017;Rabin et al., 2015). However, with present and future climate and land-use change, conditions in Australia are predicted to yield more frequent largescale fire events (Clarke et al., 2011;Di Virgilio et al., 2019;Pitman et al., 2007). According to the Australian Bureau of Meteorology (2020), the 2019 summer was the warmest (1.52°C above the national average, and driest (rainfall 40% lower than average) season on record. This provided suitable conditions for wildfires to ignite and spread.The Australian wildfires of the 2019/2020 fire season, colloquially known as the "black summer," represented some of the largest events in recent decades. The fires burned over 110,000 km 2 of bush, forest and parks (BBC, 2020). The majority of the fire activity occurred in south-eastern Australia (New South Wales and Victoria), which is predominantly eucalyptus forest and woodland (SOTE, 2016). The fires caused 33 deaths (BBC, 2020) and killed over approximately 1 billion animals (UoS, 2020). In comparison, the Black

Causes and Effects of the Long‐Range Dispersion of Carbonaceous Aerosols From the 2019–2020 Australian Wildfires

“…The 2019–2020 Black Summer (November–February) wildfires released immense volumes of smoke aerosols (Pope et al., 2021) that comprised mainly CAs (Yu et al., 2019). The smoke increased the tropospheric CAs content around southeastern Australia significantly (Figures 1a and 1c), peaking at the ∼700 hPa level (Figure 1f).…”