Two decades of fire activity over the PEEX domain : a look from space, with contribution from models and ground-based measurements

• Main Authors: Sogacheva, Larisa, Virtanen, Timo H., Sundström, Anu-Maija, Kolmonen, Pekka, Sofiev, Mikhail, Lappalainen, Hanna K., Arola, Antti
• Other Authors: Institute for Atmospheric and Earth System Research (INAR), INAR Physics
• Format: Article in Journal/Newspaper
• Language: English
• Published: Taylor & Francis 2024
• Subjects: enhancement ratios; PEEX; satellite; trend; wild fires; Physical sciences; Astronomy; Space science; Arctic; Aerosol Robotic Network; black carbon; Tundra; Siberia
• Online Access: http://hdl.handle.net/10138/576471

It has been suggested that forest fires will become more frequent/intense with changing climate, which would increase aerosol/gas emissions into the atmosphere. A better understanding of the relations between meteorological conditions, fires, and fire emissions will help estimate the climate response via forest fires. In this study, we use ERA5 meteorological products, including temperature, precipitation, and soil moisture, to explain the frequency of forest fires and the amount of radiant energy released per time unit by burning vegetation (fire radiative power, FRP). We explore the relationships between satellite-retrieved fire products and aerosol properties (aerosol optical depth, AOD), carbon monoxide (CO), formaldehyde (HCHO), and nitrogen dioxide (NO2) concentrations over the PEEX domain, which covers different vegetation zones (e.g. croplands/grasslands, forest, arctic tundra) of Pan-Eurasia and China. We analyse the concentrations of black carbon and absorbing organic carbon using ground-based AErosol RObotic NETwork. The analysis covers the months of May to August from 2002 to 2022. We show positive temperature trends in the Northern zone (>65°N) in June and August (1.56°C and 0.64°C, respectively); all statistically significant trends for precipitation and soil moisture are negative. This can explain increased fire activity in Siberia over the recent years (2019–2022). Over the whole PEEX domain, FC and FRP trends remain insignificant or negative; a decrease in AOD may address those negative trends. We show that intra-summer variations exist for cropland/grassland fires, which occur most often in May and August, while Siberian forest fires occur more often in July and August. We show that CO concentration has been gradually decreasing in the last two decades in May and June. CO trends are negative in May, June, and over summer for all regions, in July in Europe, China, the Southern zone (<55°N), and the PEEX domain. HCHO trends are not significant in all regions. NO2 trends are positive in May ...