@Article{PapastefanouZACJRRSSTVVVR:2022:AsDiPr,
author = "Papastefanou, Phillip and Zang, Christian S. and Angelov, Zlatan
and Castro, Aline Anderson de and Jimenez, Juan Carlos and
Rezende, Luiz Felipe Campos de and Ruscica, Romina C. and
Sakschewski, Boris and S{\"o}rensson, Anna A. and Thonicke,
Kirsten and Vera, Carolina and Viovy, Nicolas and Von Randow,
Celso and Rammig, Anja",
affiliation = "{Technical University of Munich} and {Weihenstephan-Triesdorf
University of Applied Sciences} and {Technical University of
Munich} and {Instituto Nacional de Pesquisas Espaciais (INPE)} and
{University of Valencia} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {Universidad de Buenos Aires} and {Potsdam
Institute for Climate Impact Research (PIK)} and {Universidad de
Buenos Aires} and {Potsdam Institute for Climate Impact Research
(PIK)} and {Universidad de Buenos Aires} and {Universit{\'e}
Paris-Saclay} and {Instituto Nacional de Pesquisas Espaciais
(INPE)} and {Technical University of Munich}",
title = "Recent extreme drought events in the Amazon rainforest: assessment
of different precipitation and evapotranspiration datasets and
drought indicators",
journal = "Biogeosciences",
year = "2022",
volume = "19",
pages = "3843--3861",
abstract = "Over the last decades, the Amazon rainforest has been hit by
multiple severe drought events. Here, we assess the severity and
spatial extent of the extreme drought years 2005, 2010 and 2015/16
in the Amazon region and their impacts on the regional carbon
cycle. As an indicator of drought stress in the Amazon rainforest,
we use the widely applied maximum cumulative water deficit (MCWD).
Evaluating nine state-of-the-art precipitation datasets for the
Amazon region, we find that the spatial extent of the drought in
2005 ranges from 2.2 to 3.0 (mean = 2.7) ×106 km2 (37 % 51 % of
the Amazon basin, mean = 45 %), where MCWD indicates at least
moderate drought conditions (relative MCWD anomaly <
\−0.5). In 2010, the affected area was about 16 % larger,
ranging from 3.0 up to 4.4 (mean = 3.6) ×106 km2 (51 %74 %, mean =
61 %). In 2016, the mean area affected by drought stress was
between 2005 and 2010 (mean = 3.2 × 106 km2 ; 55 % of the Amazon
basin), but the general disagreement between datasets was larger,
ranging from 2.4 up to 4.1 × 106 km2 (40 %69 %). In addition, we
compare differences and similarities among datasets using the
self-calibrating Palmer Drought Severity Index (scPDSI) and a
dry-season rainfall anomaly index (RAI). We find that scPDSI shows
a stronger and RAI a much weaker drought impact in terms of extent
and severity for the year 2016 compared to MCWD. We further
investigate the impact of varying evapotranspiration on the
drought indicators using two state-of-the-art evapotranspiration
datasets. Generally, the variability in drought stress is most
dependent on the drought indicator (60 %), followed by the choice
of the precipitation dataset (20 %) and the evapotranspiration
dataset (20 %). Using a fixed, constant evapotranspiration rate
instead of variable evapotranspiration can lead to an
overestimation of drought stress in the parts of Amazon basin that
have a more pronounced dry season (for example in 2010). We
highlight that even for well-known drought events the spatial
extent and intensity can strongly depend upon the drought
indicator and the data sources it is calculated with. Using only
one data source and drought indicator has the potential danger of
under- or overestimating drought stress in regions with high
measurement uncertainty, such as the Amazon basin.",
doi = "10.5194/bg-19-3843-2022",
url = "http://dx.doi.org/10.5194/bg-19-3843-2022",
issn = "1726-4170",
language = "en",
targetfile = "bg-19-3843-2022.pdf",
urlaccessdate = "05 maio 2024"
}