Observed change of the standardized precipitation index, its potential cause and implications to future climate change in the Amazon region.
Abstract
Observations show that the standard precipitation index (SPI) over the southern Amazon
region decreased in the period of 1970-1999 by 0.32 per decade, indicating an increase
in dry conditions. Simulations of constant pre-industrial climate with recent climate
models indicate a low probability (p=0%) that the trends are due to internal climate
variability. When the 23 models are forced with either anthropogenic factors or both
anthropogenic and external natural factors, approximately 13% of sampled 30-year SPI
trends from the models are found to be within the range of the observed SPI trend
at 95% confidence level. This suggests a possibility of anthropogenic and external
forcing of climate change in the southern Amazon. On average, the models project no
changes in the frequency of occurrence of low SPI values in the future; however, those
models which produce more realistic SPI climatology, variability and trend over the
period 1970-1999 show more of a tendency towards more negative values of SPI in the
future. The analysis presented here suggests a potential anthropogenic influence on
Amazon drying, which warrants future, more in-depth, study.
Type
Journal articlePermalink
https://hdl.handle.net/10161/14919Published Version (Please cite this version)
10.1098/rstb.2007.0022Publication Info
Li, Wenhong; Fu, Rong; Juárez, Robinson I Negrón; & Fernandes, Katia (2008). Observed change of the standardized precipitation index, its potential cause and implications
to future climate change in the Amazon region. Philos Trans R Soc Lond B Biol Sci, 363(1498). pp. 1767-1772. 10.1098/rstb.2007.0022. Retrieved from https://hdl.handle.net/10161/14919.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
Collections
More Info
Show full item recordScholars@Duke
Wenhong Li
Associate Professor of Climate
Dr. Li's research interests focus primarily on climate dynamics, land-atmosphere interaction,
hydroclimatology, and climate modeling. Her current research is to understand how
the hydrological cycle changes in the current and future climate and their impacts
on the ecosystems, subtropical high variability and change, unforced global temperature variability,
and climate and health issues.

Articles written by Duke faculty are made available through the campus open access policy. For more information see: Duke Open Access Policy
Rights for Collection: Scholarly Articles
Works are deposited here by their authors, and represent their research and opinions, not that of Duke University. Some materials and descriptions may include offensive content. More info