气候变化领域集成服务门户(CCPortal): Glacial to interglacial climate variability in the southeastern African subtropics (25-20° S)

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DOI	10.5194/cp-17-345-2021
	Glacial to interglacial climate variability in the southeastern African subtropics (25-20° S)
	Hahn A.; Schefuß E.; Groeneveld J.; Miller C.; Zabel M.
发表日期	2021
ISSN	1814-9324
起始页码	283
结束页码	298
卷号	17 期号:1
英文摘要	We present a continuous and well-resolved record of climatic variability for the past 100 000 years from a marine sediment core taken in Delagoa Bight, off southeastern Africa. In addition to providing a sea surface temperature reconstruction for the past ca. 100 000 years, this record also allows a high-resolution continental climatic reconstruction. Climate sensitive organic proxies, like the distribution and isotopic composition of plant-wax lipids as well as elemental indicators of fluvial input and weathering type provide information on climatic changes in the adjacent catchment areas (Incomati, Matola and Lusutfu rivers). At the transition between glacials and interglacials, shifts in vegetation correlate with changes in sea surface temperature in the Agulhas Current. The local hydrology, however, does not follow these orbitally paced shifts. Instead, precipitation patterns follow millennial-scale variations with different forcing mechanisms in glacial vs. interglacial climatic states. During glacials, southward displacement of the Intertropical Convergence Zone facilitates a transmission of northern hemispheric signals (e.g., Heinrich events) to the southern hemispheric subtropics. Furthermore, the southern hemispheric westerlies become a more direct source of precipitation as they shift northward over the study site, especially during Antarctic cold phases. During interglacials, the observed short-term hydrological variability is also a function of Antarctic climate variability; however, it is driven by the indirect influence of the southern hemispheric westerlies and the associated South African high-pressure cell blocking the South Indian Ocean Convergence Zone related precipitation. As a consequence of the interplay of these effects, smallscale climatic zones exist. We propose a conceptual model describing latitudinal shifts of these zones along the southeastern African coast as tropical and temperate climate systems shift over glacial and interglacial cycles. The proposed model explains some of the apparent contradictions between several paleoclimate records in the region. © Author(s) 2021.
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/183610
作者单位	MARUM - Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany; Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Potsdam, Germany; Leeds Trinity University, Brownberrie Ln, Horsforth, Leeds, LS18 5HD, United Kingdom
推荐引用方式 GB/T 7714	Hahn A.,Schefuß E.,Groeneveld J.,et al. Glacial to interglacial climate variability in the southeastern African subtropics (25-20° S)[J],2021,17(1).
APA	Hahn A.,Schefuß E.,Groeneveld J.,Miller C.,&Zabel M..(2021).Glacial to interglacial climate variability in the southeastern African subtropics (25-20° S).Climate of the Past,17(1).
MLA	Hahn A.,et al."Glacial to interglacial climate variability in the southeastern African subtropics (25-20° S)".Climate of the Past 17.1(2021).