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 occurren

SUBMITTER: Li W 

PROVIDER: S-EPMC2373881 | biostudies-literature | 2008 May

REPOSITORIES: biostudies-literature