Environmental Science and Engineering Seminar

The Southern Hemisphere contains extensive dryland regions that are known to strongly influence the interannual variability of the global terrestrial carbon sink. However, terrestrial carbon flux estimates in these regions remain highly uncertain due to the scarcity of in-situ observations in the Southern Hemisphere and limited knowledge about the dominant carbon exchange processes.

I will present how a decade of atmospheric CO2 concentration measurements from satellites reveals recurrent CO2 emission pulses at the end of the dry season across Australia, southern Africa, and temperate South America. By combining satellite observations with climate data, process-based vegetation models, and flux tower measurements, these emissions can be attributed to enhanced soil respiration triggered by soil rewetting in semi-arid regions. The findings suggest a continental-scale relevance of rewetting-driven soil respiration pulses-a process that is currently underrepresented in earth system models.