Methane hotspots in tropical South America |
Santiago Botia
,
Christoph Gerbig
,
Stijn Hantson
|
Project descriptionMethane (CH4) is the second most relevant greenhouse gases (after CO2) and its atmospheric concentration has risen faster than that of CO2 over the industrial period, now almost 3 times the preindustrial concentration. After an apparent stabilization of global methane levels in the early 2000s, these have been increasing again over the past 15 years. The drivers of such increase are not well understood, but some hypothesis suggest that tropical wetlands could play an important role. Tropical wetlands contribute significantly to the global methane budget, however the magnitude of the source and its variation with climate is still highly uncertain. In South America, the Amazon basin has taken most of the attention as is one of the most important natural methane hotspots in the region, but satellite data shows substantial methane source in the Orinoco basin between Colombia and Venezuela (Qu, Z., et al 2021, Balasus et al., 2023).In this project, we aim to better understand the temporal dynamics and the spatial gradients of these two methane hotspots. More specifically the project will 1) use bottom-up process-based models as input in an atmospheric transport model to simulate CH4 mole fractions and validate with multiple data streams, such as in-situ measurements and satellite column data 2) conduct regional atmospheric inverse modeling to integrate different sources of information into a consistent estimate of the wetland CH4 source 3) analysis and source identification using ongoing stable isotopes measurements in CH4 at the Amazon Tall Tower Observatory (ATTO). Working group & collaborationsThe candidate will be part of the Biogeochemical Signals department and will have the opportunity to collaborate with researchers from Colombia, Brazil, Germany and the United States.RequirementsApplications to the IMPRS-gBGC are open to well-motivated and highly-qualified students from all countries. Prerequisites for this PhD project are:
ReferencesQu, Z., Jacob, D. J., Shen, L., Lu, X., Zhang, Y., Scarpelli, T. R., Nesser, H., Sulprizio, M. P., Maasakkers, J. D., Bloom, A. A., Worden, J. R., Parker, R. J., and Delgado, A. L.: Global distribution of methane emissions: a comparative inverse analysis of observations from the TROPOMI and GOSAT satellite instruments, Atmos. Chem. Phys., 21, 14159–14175, https://doi.org/10.5194/acp-21-14159-2021, 2021.Balasus, N., Jacob, D. J., Lorente, A., Maasakkers, J. D., Parker, R. J., Boesch, H., Chen, Z., Kelp, M. M., Nesser, H., and Varon, D. J.: A blended TROPOMI+GOSAT satellite data product for atmospheric methane using machine learning to correct retrieval biases, Atmos. Meas. Tech. Discuss. [preprint], https://doi.org/10.5194/amt-2023-47, in review, 2023. |