EGU22-11505, updated on 28 Mar 2022
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Extreme droughts and floods in the Amazon forest

Gerbrand Koren1, Santiago Botía2, Lucas G. Domingues3, Liesbeth Florentie4, Luciana V. Gatti5, Manuel Gloor6, Shaun Harrigan7, Maarten C. Krol8,9, Ingrid T. Luijkx8, John B. Miller10, Stijn Naus11, and Wouter Peters8,12
Gerbrand Koren et al.
  • 1Copernicus Institute of Sustainable Development, Utrecht University, Utrecht, The Netherlands (
  • 2Max Planck Institute for Biogeochemistry, Department Biogeochemical Signals, Jena, Germany
  • 3National Isotope Centre, GNS Science, New Zealand
  • 4VU University, Faculty of Science, Earth and Climate, Amsterdam, The Netherlands
  • 5National Institute for Space Research (INPE), São José dos Campos, Brazil
  • 6University of Leeds, School of Geography, Leeds, UK
  • 7European Centre for Medium-Range Weather Forecasts (ECMWF), Reading, UK
  • 8Wageningen University, Meteorology and Air Quality Group, Wageningen, The Netherlands
  • 9Institute for Marine and Atmospheric Research Utrecht (IMAU), Utrecht University, Utrecht, The Netherlands
  • 10NOAA Global Monitoring Laboratory, Boulder, CO, USA
  • 11SRON Netherlands Institute for Space Research, Leiden, The Netherlands
  • 12University of Groningen, Centre for Isotope Research (CIO), Groningen, The Netherlands

In recent years, the Amazon forest has experienced several major droughts (2010, 2015/16) and floods (2012, 2014, 2021). Extreme events represent a threat to the Amazons important functions, but these perturbations also provide valuable insights into the underlying mechanisms. Here we studied the most recent massive drought and flood events in detail, and quantified their severity and spatiotemporal extent relative to a multi-year baseline.

First, we describe the anomalous hydrological status of these events, by bringing together a large variety of data sets, including in-situ observations and reanalysis products for precipitation, discharge, vapor pressure deficit and soil moisture. During the strong El Niño conditions following the dry season of 2015, the precipitation fell below its climatological values. This was soon reflected in low discharge rates and soil moisture levels, persisting far into the year 2016 for some regions. In contrast, we find anomalously high precipitation over the northern Amazon during the first months of 2021, resulting in high discharge rates,  and  rising river levels that have led to massive floods in downstream regions.

Finally, we quantified the impact of the 2015/16 drought on vegetation using the inverse model CarbonTacker South America (CT-SAM) and remote sensing proxies for photosynthesis. To address the uncertainty in prior emission estimates, we have used a range of different biosphere models (SiBCASA, SiB4), including a biosphere model linked to a detailed hydrological model (PCR-GLOBWB). For the fire flux we used multiple data sets (GFAS, SiBCASA-GFED4), including a modified version based on CO inversions performed with the TM5-4DVAR system. We find that photosynthesis was reduced during the 2015 drought, especially in the drier, southern part of the Amazon. This was followed by a recovery in the first months of 2016, but during the subsequent dry season a secondary impact on photosynthesis was found. The inversely derived net CO2 fluxes do not have the same high resolution as the satellite products, but when assessed over larger scales, a consistent drought signal is derived.

How to cite: Koren, G., Botía, S., Domingues, L. G., Florentie, L., Gatti, L. V., Gloor, M., Harrigan, S., Krol, M. C., Luijkx, I. T., Miller, J. B., Naus, S., and Peters, W.: Extreme droughts and floods in the Amazon forest, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11505,, 2022.