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标题：Ecological and hydroclimate responses to strengthening of the Hadley circulation in South America during the Late Miocene cooling
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作者：Barbara Carrapa ; Barbara Carrapa ; Mark Clementz 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2019
卷号：116
期号：20
页码：9747-9752
DOI：10.1073/pnas.1810721116
出版社：The National Academy of Sciences of the United States of America
摘要：Near-modern ecosystems were established as a result of rapid ecological adaptation and climate change in the Late Miocene. On land, Late Miocene aridification spread in tandem with expansion of open habitats including C₄ grassland ecosystems. Proxy records for the central Andes spanning the Late Miocene cooling (LMC) show the reorganization of subtropical ecosystems and hydroclimate in South America between 15 and 35°S. Continental pedogenic carbonates preserved in Neogene basins record a general increase of δ¹⁸O and δ¹³C values from pre-LMC to post-LMC, most robustly occurring in the subtropics (25 to 30°S), suggesting aridification and a shift toward a more C4-plant-dominated ecosystem. These changes are closely tied to the enhancement of the Hadley circulation and moisture divergence away from the subtropics toward the Intertropical Convergence Zone as revealed by climate model simulations with prescribed sea-surface temperatures (SSTs) reflecting different magnitudes of LMC steepening of equator-to-pole temperature gradient and CO₂ decline.
关键词：Late Miocene cooling ; South America ; Hadley circulation ; stable isotopes ; Andes