학술논문
Tree-ring oxygen isotopes record a decrease in Amazon dry season rainfall over the past 40 years.
Document Type
Academic Journal
Author
Cintra BBL; School of Geography, University of Leeds, Garstang North Building, Leeds, LS2 9JT UK.; Institute of Biosciences, University of São Paulo, Rua do Matão 14, São Paulo, 05508-090 Brazil.; Gloor M; School of Geography, University of Leeds, Garstang North Building, Leeds, LS2 9JT UK.; Boom A; School of Geography, Geology and the Environment, University of Leicester, Bennet Building, University Road, Leicester, LE1 7RH UK.; Schöngart J; Coordination of Environmental Dynamics, National Institute for Amazon Research, Av. André Araújo 2936, Petrópolis, Manaus, 69067-375 Brazil.; Baker JCA; School of Earth and Environment, University of Leeds, Leeds, UK.; Cruz FW; Institute of Geosciences, University of São Paulo, Rua do Lago 562, São Paulo, 05508-080 Brazil.; Clerici S; School of Geography, University of Leeds, Garstang North Building, Leeds, LS2 9JT UK.; Brienen RJW; School of Geography, University of Leeds, Garstang North Building, Leeds, LS2 9JT UK.
Source
Publisher: Springer-International Country of Publication: Germany NLM ID: 101625237 Publication Model: Print-Electronic Cited Medium: Print ISSN: 0930-7575 (Print) Linking ISSN: 09307575 NLM ISO Abbreviation: Clim Dyn Subsets: PubMed not MEDLINE
Subject
Language
English
ISSN
0930-7575
Abstract
Extant climate observations suggest the dry season over large parts of the Amazon Basin has become longer and drier over recent decades. However, such possible intensification of the Amazon dry season and its underlying causes are still a matter of debate. Here we used oxygen isotope ratios in tree rings (δ 18 O TR ) from six floodplain trees from the western Amazon to assess changes in past climate. Our analysis shows that δ 18 O TR of these trees is negatively related to inter-annual variability of precipitation during the dry season over large parts of the Amazon Basin, consistent with a Rayleigh rainout model. Furthermore δ 18 O TR increases by approximately 2‰ over the last four decades (~ 1970-2014) providing evidence of an Amazon drying trend independent from satellite and in situ rainfall observations. Using a Rayleigh rainout framework, we estimate basin-wide dry season rainfall to have decreased by up to 30%. The δ 18 O TR record further suggests such drying trend may not be unprecedented over the past 80 years. Analysis of δ 18 O TR with sea surface temperatures indicates a strong role of a warming Tropical North Atlantic Ocean in driving this long-term increase in δ 18 O TR and decrease in dry season rainfall.
Supplementary Information: The online version contains supplementary material available at 10.1007/s00382-021-06046-7.
Competing Interests: Conflict of interestThe authors declare there are no conflicts of interest.
(© The Author(s) 2021.)
Supplementary Information: The online version contains supplementary material available at 10.1007/s00382-021-06046-7.
Competing Interests: Conflict of interestThe authors declare there are no conflicts of interest.
(© The Author(s) 2021.)