Causes and Impact of the 2005 Amazon Drought
A rare drought in the Amazon basin that culminated in 2005 drew wide attention to the potential vulnerability of tropical rainforest to natural and anthropogenic perturbations. Using ground and satellite observations, we show that Amazon rainfall in 2005 was indeed below normal but the deficit was n...
| Main Authors: | , , , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
2006
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.395.1794 http://www.atmos.umd.edu/~zeng/papers/Zeng06_Amazon_drought.pdf |
| Summary: | A rare drought in the Amazon basin that culminated in 2005 drew wide attention to the potential vulnerability of tropical rainforest to natural and anthropogenic perturbations. Using ground and satellite observations, we show that Amazon rainfall in 2005 was indeed below normal but the deficit was not particularly large. Rather, it was the last episode of an unusually long drought started in 2002, leading to the severe depletion of soil moisture and lowering of water levels. The wide-ranging impact of this long-lasting drought can be seen in the lowest river stage in the 25 year data period for the upper Amazon, 16 % reduction in the river plume size in the Atlantic Ocean created by Amazon runoff and over 100 % more frequent basin-wide fire occurrence compared to the averages of previous 7 years. Atmospheric data analysis and modeling results suggest that the 2005 drought was caused largely by a warm tropical North Atlantic Ocean that generated a seasaw-like modification of the Hadley circulation, corresponding to reduced moisture transport into the Amazon basin. This is in contrast to a conventional wisdom of Pacific Ocean sea surface temperature (SST) control on Amazon rainfall via the El Nino Southern Oscillation (ENSO). Using |
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