Comment on egusphere-2025-6213

Abstract

Abstract. In 2019, Brazil experienced an intensive fire season, despite the absence of major climate anomalies to enhance fire activity. Existing carbon monoxide (CO) emission estimates from state-of-the-art fire emission inventories differ by a factor two for the period and region. We provide a top-down estimate on CO emissions from these fires using the new CarbonTracker Europe – Long/Short Window (CTE-LW/SW) inverse modelling framework driven by column-averaged dry air CO mole fractions (XCO) from the MOPITT and TROPOMI satellite instruments. Our analysis indicates that the 2019 fires in Brazil released approximately 47 TgCO. Although structural atmospheric-chemistry related uncertainties remain (±15 TgCO), the inversions converged strongly to a common posterior (46–48 TgCO) independent of the prior emission inventory (GFED5.1, GFAS v1.2) or assimilated dataset (TROPOMI, MOPITT). Posterior fire emissions closely resemble the newly released GFED5.1, supporting recent advances in bottom-up fire modelling. Nonetheless, at the biome level, our results reveal a systematic underestimation—by roughly a factor of two—in the Cerrado and Caatinga savannas relative to both fire emission priors. While more targeted uncertainty assessments are required, we speculate that this emission gap unlikely stems from inversion choices alone and may indicate an underestimation of fuel loads or emission factors. Overall, we demonstrate CTE-LW/SW effectively leverages XCO to complement existing fire emission monitoring capacities at increasingly fine spatial resolution—a capability that is especially valuable in Brazil, where different fire regimes occur in close proximity and fire activity has intensified in recent years.

Authors 11

1. Anne-Wil Van den Berg

   Wageningen University & Research

   Affiliation as printed

   Meteorology and Air Quality group, Wageningen University and Research, Wageningen, the Netherlands

2. Joram Hooghiem

   Wageningen University & Research

   Affiliation as printed

   Meteorology and Air Quality group, Wageningen University and Research, Wageningen, the Netherlands

3. Auke Marijn van der Woude

   Wageningen University & Research

   Affiliation as printed

   Meteorology and Air Quality group, Wageningen University and Research, Wageningen, the Netherlands

4. Pieter Rijsdijk Aachen Space Research Organization Netherlands (SRON)

   Royal Netherlands Meteorological Institute · Space Research Organisation Netherlands · Vrije Universiteit Amsterdam

   Affiliation as printed

   Department of Earth Sciences, Vrije Universiteit, Amsterdam, the Netherlands

   Satellite Observations department, Royal Netherlands Meteorological Institute, De Bilt, the Netherlands

   Space Research Organization Netherlands, Leiden, the Netherlands

5. Roland Vernooij

   Wageningen University & Research

   Affiliation as printed

   Meteorology and Air Quality group, Wageningen University and Research, Wageningen, the Netherlands

6. Santiago Botía

   Max Planck Institute for Biogeochemistry

   Affiliation as printed

   Department of Biogeochemical Signals, Max Planck Institute for Biogeochemistry, Jena, Germany

7. Guido R. van der Werf

   Wageningen University & Research

   Affiliation as printed

   Meteorology and Air Quality group, Wageningen University and Research, Wageningen, the Netherlands

8. John B. Miller

   National Oceanic and Atmospheric Administration · NOAA Global Monitoring Laboratory

   Affiliation as printed

   Carbon Cycle Greenhouse Gases Division, National Oceanic and Atmospheric Administration Global Monitoring Laboratory, Boulder Colorado, United States of America

9. Ingrid T. Luijkx

   Wageningen University & Research

   Affiliation as printed

   Meteorology and Air Quality group, Wageningen University and Research, Wageningen, the Netherlands

10. Maarten Krol

    Utrecht University · Wageningen University & Research

    Affiliation as printed

    Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, the Netherlands

    Meteorology and Air Quality group, Wageningen University and Research, Wageningen, the Netherlands

11. Wouter Peters

    University of Groningen · Wageningen University & Research

    Affiliation as printed

    Centre for Isotope Research, University of Groningen, Groningen, the Netherlands

    Meteorology and Air Quality group, Wageningen University and Research, Wageningen, the Netherlands