Causes and Impacts of the 2005 Amazon Drought
Prof. Ning Zeng
U. Maryland/AOSC
Collaborators: Jin-Ho Yoon, Jose A. Marengo, Ajit Subramaniam, Carlos A. Nobre, Annarita Mariotti, J. David Neelin
A rare drought in the Amazon Basin culminated in 2005, leading to near
record-low streamflows, small Amazon river plume, and greatly enhanced
fire frequency. This episode was caused by a combination of 2002-03 El
Niño and a dry spell in 2005 attributable to a warm subtropical North
Atlantic Ocean. An analysis of 10 precipitation datasets for the
period 1979-2005 reveals that Atlantic influence on Amazon rainfall is
comparable to the better known Pacific linkage. While El Niño
influence is typically locked to the wet season, the 2005 Atlantic
impact concentrated in the Amazon dry season when the hydroecosystem
was most vulnerable. Such mechanisms may have wide-ranging
implications for the past and future changes in the world's largest
tropical rainforest in response to natural and anthropogenic
perturbations.