DOI: 10.5194/cp-11-1417-2015
Scopus记录号: 2-s2.0-84946737923
论文题名: Increased aridity in southwestern Africa during the warmest periods of the last interglacial
作者: Urrego D.H. ; Sánchez Goñi M.F. ; Daniau A.-L. ; Lechevrel S. ; Hanquiez V.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2015
卷: 11, 期: 10 起始页码: 1417
结束页码: 1431
语种: 英语
Scopus关键词: aridity
; climate variation
; glacial-interglacial cycle
; ice cap
; intertropical convergence zone
; isotopic analysis
; Last Interglacial
; Northern Hemisphere
; paleoclimate
; precipitation (climatology)
; savanna
; Africa
; Karoo
; Nama Karoo
; South Africa
英文摘要: Terrestrial and marine climatic tracers from marine core MD96-2098 were used to reconstruct glacial-interglacial climate variability in southwestern Africa between 194 and 24 thousand years before present. The pollen record documented three pronounced expansions of Nama-karoo and fine-leaved savanna during the last interglacial (Marine Isotopic Stage 5 - MIS 5). These Nama-karoo and fine-leaved savanna expansions were linked to increased aridity during the three warmest substadials of MIS 5. Enhanced aridity potentially resulted from a combination of reduced Benguela Upwelling, expanded subtropical high-pressure cells, and reduced austral-summer precipitation due to a northward shift of the Intertropical Convergence Zone. Decreased austral-winter precipitation was likely linked to a southern displacement of the westerlies. In contrast, during glacial isotopic stages MIS 6, 4 and 3, fynbos expanded at the expense of Nama-karoo and fine-leaved savanna indicating a relative increase in precipitation probably concentrated during the austral winter months. Our record also suggested that warm-cold or cold-warm transitions between isotopic stages and substages were punctuated by short increases in humidity. Increased aridity during MIS 5e, 5c and 5a warm substages coincided with minima in both precessional index and global ice volume. On the other hand, austral-winter precipitation increases were associated with precession maxima at the time of well-developed Northern Hemisphere ice caps. © Author(s) 2015.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49103
Appears in Collections: 气候变化与战略
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Recommended Citation:
Urrego D.H.,Sánchez Goñi M.F.,Daniau A.-L.,et al. Increased aridity in southwestern Africa during the warmest periods of the last interglacial[J]. Climate of the Past,2015-01-01,11(10)