In the Atmosphere-Biosphere Signal Attribution (BSAT) research group our main objective is to understand tropical ecosystem dynamics by investigating and monitoring changes in atmospheric trace gases like CO2, CH4 and CO. We aim to (1) quantify and attribute sources and sinks of CO2, CH4 and CO and (2) to study their development over time and at different spatial scales under a changing climate. For this we combine top-down (atmospheric inversions) and bottom-up (land surface models) approaches with multiple data streams, like in-situ or flask mole fraction measurements and remotely-sensed atmospheric composition. Our group complements the regional scale modeling with local process understanding by studying ecosystem response to environmental drivers using eddy covariance and stable isotope on CO2 and CH4.
The overarching goals guiding our research are:
Improve estimates and reduce uncertainty of net exchange of CO2 and CH4 over the tropical ecosystems.
Disentangle the main drivers of net ecosystem exchange (NEE) and net biome exchange (NBE) in individual tropical ecosystems but also at the pan-tropical scale.
To better quantify spatial and temporal patterns in tropical biogenic methane emissions and to provide insights into the current global methane growth rate.
Use stable isotopes in CH4 to improve the characterization of source signatures in the tropics with the aim to advance our understanding in interannual emission patterns.
Selected Figures:
Relationship between prior and posterior mean net land flux (FNetLand) in Tropical South America. On the y and x axes of each panel the density distribution is shown. Botía et al., (2025): https://doi.org/10.5194/acp-25-6219-2025.
Relationship between prior and posterior mean net land flux (FNetLand) in Tropical South America. On the y and x axes of each panel the density distribution is shown. Botía et al., (2025): https://doi.org/10.5194/acp-25-6219-2025.
Botia, S.; Dias-Junior, C. Q.; Komiya, S.; van der Woude, A.; Terristi, M.; de Kok, R.; Koren, G.; van Asperen, H.; Jones, S. P.; D'Oliveira, F. A. F.et al.; Weber, U.; Marques-Filho, E.; Toro, I. M. C.; Araújo, A.; Lavric, J.; Walter, D.; Li, X.; Wigneron, J.-P.; Stocker, B.; de Souza, J. G.; O'Sullivan, M.; Sitch, S.; Ciais, P.; Chevallier, F.; Li, W.; Luijkx, I. T.; Peters, W.; Quesada, C. A.; Zaehle, S.; Trumbore, S. E.; Bastos, A.: Reduced vegetation uptake during the extreme 2023 drought turns the Amazon into a weak carbon source. AGU Advances 7 (1), e2025AV001658 (2026)
Tran, D. A.; de Arellano, J. V.-G.; Luijkx, I. T.; Gerbig, C.; Galkowski, M.; Botia, S.; Faassen, K.; Zaehle, S.: Increasing diurnal and seasonal amplitude of atmospheric methane mole fraction in Central Siberia between 2010–2021. Atmospheric Chemistry and Physics 25 (22), pp. 16553 - 16588 (2025)
Faassen, K. A. P.; González‐Armas, R.; Koren, G.; Adnew, G. A.; van Asperen, H.; de Boer, H.; Botia, S.; de Feiter, V. S.; Hartogensis, O.; Heusinkveld, B. G.et al.; Hulsman, L. M.; Hutjes, R. W. A.; Jones, S. P.; Kers, B. A. M.; Komiya, S.; Machado, L. A. T.; Martins, G.; Miller, J. B.; Mol, W.; van der Molen, M.; Moonen, R.; Dias‐Junior, C. Q.; Röckmann, T.; Snellen, H.; Luijkx, I. T.; de Arellano, J. V.: Tracing diurnal variations of atmospheric CO2, O2, and delta 13CO2 over a tropical and a temperate forest. Geophysical Research Letters 52 (20), e2025GL118016 (2025)
Munassar, S.; Rödenbeck, C.; Galkowski, M.; Koch, F.-T.; Totsche, K. U.; Botia, S.; Gerbig, C.: To what extent does the CO2 diurnal cycle impact flux estimates derived from global and regional inversions? Atmospheric Chemistry and Physics 25 (1), pp. 639 - 656 (2025)
Glauch, T.; Marshall, J.; Gerbig, C.; Botia, S.; Galkowski, M.; Vardag, S. N.; Butz, A.: pyVPRM: a next-generation vegetation photosynthesis and respiration model for the post-MODIS era. Geoscientific Model Development 18 (14), pp. 4713 - 4742 (2025)
Ho, D.; Galkowski, M.; Reum, F.; Botia, S.; Marshall, J.; Totsche, K. U.; Gerbig, C.: Recommended coupling to global meteorological fields for long-term tracer simulations with WRF-GHG. Geoscientific Model Development 17 (20), pp. 7401 - 7422 (2024)
Machado, L. A. T.; Kesselmeier, J.; Botia, S.; van Asperen, H.; Andreae, M. O.; de Araújo, A. C.; Artaxo, P.; Edtbauer, A.; Ferreira, R. R.; Franco, M. A.et al.; Harder, H.; Jones, S. P.; Dias-Júnior, C. Q.; Haytzmann, G. G.; Quesada, C. A.; Komiya, S.; Lavrič, J. V.; Lelieveld, J.; Levin, I.; Nölscher, A.; Pfannerstill, E.; Pöhlker, M. L.; Pöschl, U.; Ringsdorf, A.; Rizzo, L.; Yáñez-Serrano, A. M.; Trumbore, S. E.; Valenti, W. I. D.; de Arellano, J. V.-G.; Walter, D.; Williams, J.; Wolff, S.; Pöhlker, C.: How rainfall events modify trace gas mixing ratios in central Amazonia. Atmospheric Chemistry and Physics 24 (15), pp. 8893 - 8910 (2024)
de Arellano, J. V.-G.; Hartogensis, O. K.; de Boer, H.; Moonen, R.; González-Armas, R.; Janssens, M.; Adnew, G. A.; Bonell-Fontás, D. J.; Botia, S.; Jones, S. P.et al.; van Asperen, H.; Komiya, S.; de Feiter, V. S.; Rikkers, D.; de Haas, S.; Machado, L. A. T.; Dias-Junior, C. Q.; Giovanelli-Haytzmann, G.; Valenti, W. I. D.; Figueiredo, R. C.; Farias, C. S.; Hall, D. H.; Mendonça, A. C. S.; da Silva, F. A. G.; da Silva, J. L. M.; Souza, R.; Martins, G.; Miller, J. N.; Mol, W. B.; Heusinkveld, B.; van Heerwaarden, C. C.; D’Oliveira, F. A. F.; Ferreira, R. R.; Gotuzzo, R. A.; Pugliese, G.; Williams, J.; Ringsdorf, A.; Edtbauer, A.; Quesada, C. A.; Portela, B. T. T.; Alves, E. G.; Pöhlker, C.; Trumbore, S. E.; Lelieveld, J.; Röckmann, T.: CloudRoots-Amazon22: Integrating clouds with photosynthesis by crossing scales. Bulletin of the American Meteorological Society 105 (7), pp. E1275 - E1302 (2024)
The Amazon rainforest experienced unusually high temperatures and atmospheric dryness in 2023. Observations from ATTO and further data revealed that the vegetation’s uptake of carbon was above average early in the year, but drastically reduced during the drought season, leading from a carbon sink into a source.
Extreme precipitation should increase with warmer temperatures. Data from tropical regions show that this correlation is obscured by the cooling effect of clouds. When cloud effects are corrected, the increase in extreme precipitation with rising temperatures becomes apparent.
Tropical forests are continuously being fragmented and damaged by human influences. Using remote sensing data and cutting-edge data analysis methods, researchers can now show for the first time that the impact of this damage is greater than previously estimated.
Researchers are using Biosphere 2 to study how H2O, CO2 and VOCs flow through drought-stressed plants and soils in the largest labeling experiment to date. The study results can help make forests more resilient and climate models more accurate.
Rainforests are being lost through deforestation and land use. This reduces their resilience to climate change and makes them more vulnerable to droughts and wildfires. A new early warning system responds to the different conditions of rainforests.
