EGU2020-4020
https://doi.org/10.5194/egusphere-egu2020-4020
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

SMOS-IC L-VOD reveals that tropical forests did not recover from the strong 2015–2016 El Niño event

Lei Fan1,2, Jean-pierre Wigneron2, Philippe Ciais3, Ana Bastos4, Martin Brandt5, Jérome Chave6, Sassan Saatchi7, Alessandro Baccini8, and Rasmus Fensholt5
Lei Fan et al.
  • 1Nanjing University of Information Science & Technology, China (fanlei20088@163.com)
  • 2ISPA, UMR 1391, INRA Nouvelle-Aquitaine, Université de Bordeaux, Grande Ferrade, Villenave d’Ornon, France.
  • 3Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
  • 4Department of Geography, Ludwig-Maximilians Universität, Luisenstr. 37, 80333 Munich, Germany
  • 5Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
  • 6Laboratoire Evolution and Diversité Biologique, Bâtiment 4R3 Université Paul Sabatier, Toulouse, France
  • 7Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
  • 8Woods Hole Research Center, 149 Woods Hole Road, Falmouth, MA 02540-1644, USA.

Severe drought and extreme heat associated with the 2015–2016 El Niño event have led to large carbon emissions from the tropical vegetation to the atmosphere. With the return to normal climatic conditions in 2017, tropical forest aboveground carbon (AGC) stocks are expected to partly recover due to increased productivity, but the intensity and spatial distribution of this recovery are unknown. Simulations from land-surface models used in the global carbon budget (GCB) suggest a strong reinvigoration of the tropical land sink after the 2015–2016 El Niño. However, models and atmospheric inversions display large divergences in tropical CO2 fluxes during the 2017 recovery event. For instance, models predict a total net land sink recovery (2017 sink minus the 2015–2016 average sink) ranging from 0.3 to 2.6 Pg C, and the land sink recovery estimated from five atmospheric inversions ranges from −0.08 to +1.92 Pg C. The results of different inversions show a large spread in the tropics due to the scarcity of stations and uncertainties in atmospheric transport simulations.

We used low-frequency microwave satellite data (L-VOD) to feature precise monitoring of AGC changes and show that the AGC recovery of tropical ecosystems was slow and that by the end of 2017, AGC had not reached predrought levels of 20141. From 2014 to 2017, tropical AGC stocks decreased by 1.3 Pg C due to persistent AGC losses in Africa (-0.9 Pg C) and America (-0.5 Pg C). Pantropically, drylands recovered their carbon stocks to pre–El Niño levels, but African and American humid forests did not, suggesting carryover effects from enhanced forest mortality.

 

Reference

How to cite: Fan, L., Wigneron, J., Ciais, P., Bastos, A., Brandt, M., Chave, J., Saatchi, S., Baccini, A., and Fensholt, R.: SMOS-IC L-VOD reveals that tropical forests did not recover from the strong 2015–2016 El Niño event, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4020, https://doi.org/10.5194/egusphere-egu2020-4020, 2020