1. Respiration driven CO2 pulses dominate Australia's flux variability
- Author
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Metz, Eva-Marie, Vardag, Sanam N., Basu, Sourish, Jung, Martin, Ahrens, Bernhard, El-Madany, Tarek, Sitch, Stephen, Arora, Vivek K., Briggs, Peter R., Friedlingstein, Pierre, Goll, Daniel S., Jain, Atul K., Kato, Etsushi, Lombardozzi, Danica, Nabel, Julia E. M. S., Poulter, Benjamin, Séférian, Roland, Tian, Hanqin, Wiltshire, Andrew, Yuan, Wenping, Yue, Xu, Zaehle, Sönke, Deutscher, Nicholas M., Griffith, David W. T., and Butz, André
- Subjects
Physics - Atmospheric and Oceanic Physics - Abstract
The Australian continent contributes substantially to the year-to-year variability of the global terrestrial carbon dioxide (CO2) sink. However, the scarcity of in-situ observations in remote areas prevents deciphering the processes that force the CO2 flux variability. Here, examining atmospheric CO2 measurements from satellites in the period 2009-2018, we find recurrent end-of-dry-season CO2 pulses over the Australian continent. These pulses largely control the year-to-year variability of Australia's CO2 balance, due to 2-3 times higher seasonal variations compared to previous top-down inversions and bottom-up estimates. The CO2 pulses occur shortly after the onset of rainfall and are driven by enhanced soil respiration preceding photosynthetic uptake in Australia's semi-arid regions. The suggested continental-scale relevance of soil rewetting processes has large implications for our understanding and modelling of global climate-carbon cycle feedbacks., Comment: 28 pages (including supplementary materials), 3 main figures, 7 supplementary figures; v2 changes: Last name of first author changed
- Published
- 2022
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