气候变化领域集成服务门户(CCPortal): Reconstruction of Holocene coupling between the South America Monsoon System and local moisture variability from speleothem δ 18 O and 87 Sr/ 86 Sr records

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DOI	10.1016/j.quascirev.2019.02.019
	Reconstruction of Holocene coupling between the South America Monsoon System and local moisture variability from speleothem δ 18 O and 87 Sr/ 86 Sr records
	Ward B.M.; Wong C.I.; Novello V.F.; McGee D.; Santos R.V.; Silva L.C.R.; Cruz F.W.; Wang X.; Edwards R.L.; Cheng H.
发表日期	2019
ISSN	0277-3791
起始页码	51
结束页码	63
卷号	210
英文摘要	Investigating controls on past variability of South American hydroclimate is critical to assessing its response to future warming scenarios. δ 18 O records from South America offer insight into past variability of the South American Monsoon System (SAMS). The controls, however, on precipitation δ 18 O values can be decoupled from precipitation amount at a given site and, thereby, limit local moisture condition reconstructions. Here we use a principal components analysis to assess the coherence of speleothem and lake core Holocene δ 18 O records in tropical and subtropical South America to evaluate the extent to which δ 18 O variability reflects changes in SAMS intensity at different sites across the region. The main mode of variability across Holocene δ 18 O records (PC1) closely tracks austral summertime insolation, consistent with existing work. Sites towards the periphery of the continent are heavily weighted on PC1, whereas interior sites as not. Further δ 18 O variability at interior sites bear little similarity to each other and implicate controls, beyond regional monsoon intensity, on these δ 18 O records. Further, we develop speleothem 87 Sr/ 86 Sr records spanning the Holocene from Tamboril Cave (Brazilian Highlands), Paraíso Cave (eastern Amazon Basin), Jaraguá Cave (Mato Grosso do Sul Plateau), and Botuverá Cave (Atlantic coastal plain) to investigate coupling between reconstructed monsoon variability (reflected by PC1) and local moisture conditions (interpreted from 87 Sr/ 86 Sr records). We interpret speleothem 87 Sr/ 86 Sr variability as a proxy of local moisture conditions, reflecting the degree of water-rock interaction with the cave host rock as driven by variations in water residence time. Speleothem 87 Sr/ 86 Sr records from all the sites, except Botuverá cave, do not co-vary with PC1, suggesting that local moisture conditions do not necessarily follow variations in regional monsoon intensity at these interior sites. These speleothem 87 Sr/ 86 Sr records generally suggest dry mid-Holocene conditions relative to the early- and late-Holocene, consistent with interpretations of other paleo-moisture records in the region, but timing of wet-dry transitions varies between sites. These results highlight that controls, in addition to SAMS variability, might influence δ 18 O variability. Further, our results suggest spatially variable local moisture conditions at interior sites that do not uniformly respond to regional monsoon intensity, and stress the need for δ 18 O-independent reconstructions of moisture conditions. © 2019 Elsevier Ltd
英文关键词	Holocene; Monsoon; Oxygen isotopes; Paleoclimatology; South America; Speleothems; Strontium isotopes
语种	英语
scopus关键词	Atmospheric thermodynamics; Caves; Isotopes; Principal component analysis; Repair; Tropics; Holocenes; Monsoon; Oxygen isotopes; Paleoclimatology; South America; Speleothems; Strontium isotopes; Moisture; cave; Holocene; host rock; moisture content; monsoon; oxygen isotope; paleoclimate; paleoenvironment; precipitation (climatology); reconstruction; seasonal variation; speleothem; strontium isotope; water-rock interaction; Amazon Basin; Brazil; Mato Grosso do Sul
来源期刊	Quaternary Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/151983
作者单位	Department of Earth and Environmental Sciences, Boston College, Chestnut Hill, MA, United States; Faculty of Science and Engineering, University of Waikato, Hamilton, New Zealand; Instituto de Geociências, Universidade de São Paulo, São Paulo, Brazil; Massachusetts Institute of Technology, Cambridge, MA, United States; Institute of Geociências, Universidade de Brasilia, Brazil; Department of Geography and Environmental Studies Program, University of Oregon, Eugene, OR, United States; Earth Observatory of Singapore, Nanyang Technological University, Singapore; Department of Geology and Geophysics, University of Minnesota, Twin Cities, MN, United States; Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, China
推荐引用方式 GB/T 7714	Ward B.M.,Wong C.I.,Novello V.F.,et al. Reconstruction of Holocene coupling between the South America Monsoon System and local moisture variability from speleothem δ 18 O and 87 Sr/ 86 Sr records[J],2019,210.
APA	Ward B.M..,Wong C.I..,Novello V.F..,McGee D..,Santos R.V..,...&Cheng H..(2019).Reconstruction of Holocene coupling between the South America Monsoon System and local moisture variability from speleothem δ 18 O and 87 Sr/ 86 Sr records.Quaternary Science Reviews,210.
MLA	Ward B.M.,et al."Reconstruction of Holocene coupling between the South America Monsoon System and local moisture variability from speleothem δ 18 O and 87 Sr/ 86 Sr records".Quaternary Science Reviews 210(2019).