DOI: 10.1016/j.quascirev.2014.10.011
Scopus记录号: 2-s2.0-84909619759
论文题名: Influence of tropical easterlies in southern Africa's winter rainfall zone during the Holocene
作者: Chase B.M. ; Lim S. ; Chevalier M. ; Boom A. ; Carr A.S. ; Meadows M.E. ; Reimer P.J.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 107 起始页码: 138
结束页码: 148
语种: 英语
英文关键词: Climate change
; Holocene
; Palaeoclimate
; Pollen
; Quaternary
; Rock hyrax midden
; Southern Africa
; δ13C
; δ15N
Scopus关键词: Climate change
; Isotopes
; Tropics
; Holocenes
; Palaeoclimate
; Pollen
; Quaternary
; Southern Africa
; Rain
; climate variation
; Holocene
; humidity
; long-term change
; midden
; paleoclimate
; palynology
; rainfall
; seasonality
; Southern Hemisphere
; tropical environment
; Southern Africa
; Procavia capensis
英文摘要: South Africa's southwestern Cape occupies a critical transition zone between Southern Hemisphere temperate (winter) and tropical (summer) moisture-bearing systems. In the recent geological past, it has been proposed that the relative influence of these systems may have changed substantially, but little reliable evidence regarding regional hydroclimates and rainfall seasonality exists to refine or substantiate the understanding of long-term dynamics. In this paper we present a mid-to late Holocene multi-proxy record of environmental change from a rock hyrax midden from Katbakkies Pass, located along the modern boundary between the winter and summer rainfall zones. Derived from stable carbon and nitrogen isotopes, fossil pollen and microcharcoal, these data provide a high resolution record of changes in humidity, and insight into changes in rainfall seasonality. Whereas previous work concluded that the site had generally experienced only subtle environmental change during the Holocene, our records indicate that significant, abrupt changes have occurred in the region over the last 7000 years. Contrary to expectations based on the site's location, these data indicate that the primary determinant of changes in humidity is summer rather than winter rainfall variability, and its influence on drought season intensity and/or length. These findings are consistent with independent records of upwelling along the southern and western coasts, which indicate that periods of increased humidity are related to increased tropical easterly flow. This substantially refines our understanding of the nature of temperate and tropical circulation system dynamics in SW Africa, and how changes in their relative dominance have impacted regional environments during the Holocene. © 2014 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60063
Appears in Collections: 过去全球变化的重建
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作者单位: Centre National de Recherche Scientifique, UMR 5554, Institut des Sciences de l'Evolution de Montpellier, Université Montpellier 2, Bat.22, CC061, Place Eugène Bataillon, Montpellier Cedex 5, France; Department of Archaeology, History, Culture and Religion, University of Bergen, Postbox 7805, Bergen, Norway; Department of Geography, University of Leicester, Leicester, United Kingdom; Department of Environmental and Geographical Science, University of Cape Town, Private Bag X3, Rondebosch, South Africa; School of Geography, Archaeology and Palaeoecology, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
Recommended Citation:
Chase B.M.,Lim S.,Chevalier M.,et al. Influence of tropical easterlies in southern Africa's winter rainfall zone during the Holocene[J]. Quaternary Science Reviews,2015-01-01,107