气候变化领域集成服务门户(CCPortal): Late quaternary climate variability at mfabeni peatland; eastern south africa

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DOI	10.5194/cp-15-1153-2019
	Late quaternary climate variability at mfabeni peatland; eastern south africa
	Miller C.; Finch J.; Hill T.; Peterse F.; Humphries M.; Zabel M.; Schefuß E.
发表日期	2019
ISSN	18149324
起始页码	1153
结束页码	1170
卷号	15 期号:3
英文摘要	The scarcity of continuous, terrestrial, palaeoenvironmental records in eastern South Africa leaves the evolution of late Quaternary climate and its driving mechanisms uncertain. Here we use a 7m long core from Mfabeni peatland (KwaZulu-Natal, South Africa) to reconstruct climate variability for the last 32 000 years (cal ka BP).We infer past vegetation and hydrological variability using stable carbon (δ13Cwax) and hydrogen isotopes (δDwax) of plant-wax n-Alkanes and use Paq to reconstruct water table changes. Our results indicate that late Quaternary climate in eastern South Africa did not respond directly to orbital forcing or to changes in sea-surface temperatures (SSTs) in the western Indian Ocean. We attribute the arid conditions evidenced at Mfabeni during the Last Glacial Maximum (LGM) to low SSTs and an equatorward displacement of (i) the Southern Hemisphere westerlies, (ii) the subtropical high-pressure cell, and (iii) the South Indian Ocean Convergence Zone (SIOCZ), which we infer was linked to increased Antarctic sea-ice extent. The northerly location of the high-pressure cell and the SIOCZ inhibited moisture advection inland and pushed the rain-bearing cloud band north of Mfabeni, respectively. The increased humidity at Mfabeni between 19 and 14 cal kyr BP likely resulted from a southward retreat of the westerlies, the high-pressure cell, and the SIOCZ, consistent with a decrease in Antarctic sea-ice extent. Between 14 and 5 cal kyr BP, when the westerlies, the high-pressure cell, and the SIOCZ were in their southernmost position, local insolation became the dominant control, leading to stronger atmospheric convection and an enhanced tropical easterly monsoon. Generally drier conditions persisted during the past ca. 5 cal ka BP, probably resulting from an equatorward return of the westerlies, the high-pressure cell, and the SIOCZ. Higher SSTs and heightened El Niño-Southern Oscillation (ENSO) activity may have played a role in enhancing climatic variability during the past ca. 5 cal ka BP. Our findings highlight the influence of the latitudinal position of the westerlies, the high-pressure cell, and the SIOCZ in driving climatological and environmental changes in eastern South Africa. © Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	atmospheric convection; climate variation; El Nino-Southern Oscillation; environmental change; historical record; Last Glacial Maximum; paleoclimate; paleoenvironment; paleohydrology; Quaternary; reconstruction; Southern Hemisphere; westerly; Indian Ocean; Indian Ocean (South); KwaZulu-Natal; South Africa
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/146805
作者单位	MARUM-Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany; School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa; Department of Earth Sciences, Utrecht University, Utrecht, Netherlands; Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, South Africa
推荐引用方式 GB/T 7714	Miller C.,Finch J.,Hill T.,et al. Late quaternary climate variability at mfabeni peatland; eastern south africa[J],2019,15(3).
APA	Miller C..,Finch J..,Hill T..,Peterse F..,Humphries M..,...&Schefuß E..(2019).Late quaternary climate variability at mfabeni peatland; eastern south africa.Climate of the Past,15(3).
MLA	Miller C.,et al."Late quaternary climate variability at mfabeni peatland; eastern south africa".Climate of the Past 15.3(2019).