DOI: 10.5194/cp-10-2153-2014
Scopus记录号: 2-s2.0-84916942694
论文题名: Climate history of the Southern Hemisphere Westerlies belt during the last glacial-interglacial transition revealed from lake water oxygen isotope reconstruction of Laguna Potrok Aike (52° S, Argentina)
作者: Zhu J. ; Lücke A. ; Wissel H. ; Mayr C. ; Enters D. ; Ja Kim K. ; Ohlendorf C. ; Schäbitz F. ; Zolitschka B.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2014
卷: 10, 期: 6 起始页码: 2153
结束页码: 2169
语种: 英语
Scopus关键词: air temperature
; climate variation
; evaporation
; lake water
; Last Glacial-Interglacial
; moss
; oxygen isotope
; permafrost
; precipitation intensity
; proxy climate record
; reconstruction
; residence time
; Southern Hemisphere
; warming
; westerly
; Argentina
; Laguna Potrok Aike
; Santa Cruz [Argentina]
; Bryophyta
英文摘要: The Southern Hemisphere Westerlies (SHW) play a crucial role in large-scale ocean circulation and global carbon cycling. Accordingly, the reconstruction of how the latitudinal position and intensity of the SHW belt changed during the last glacial termination is essential for understanding global climatic fluctuations. The southernmost part of the South American continent is the only continental mass intersecting a large part of the SHW belt. However, due to the scarcity of suitable palaeoclimate archives continuous proxy records back to the last glacial are rare in southern Patagonia. Here, we show an oxygen isotope record from cellulose and purified bulk organic matter of submerged aquatic moss shoots from Laguna Potrok Aike (52° S, 70° W), a deep maar lake located in semi-arid, extra-Andean Patagonia, covering the last glacial-interglacial transition (26 000 to 8500 cal BP). Based on the highly significant correlation between oxygen isotope values of modern aquatic mosses and their host waters and abundant well-preserved moss remains in the sediment record a high-resolution reconstruction of the lake water oxygen isotope (δ18Olw-corr) composition is presented. The reconstructed δ 18Olw-corr values for the last glacial are ca. 3% lower than modern values, which can best be explained by generally cooler air temperatures and changes in the moisture source area, together with the occurrence of permafrost leading to a prolonged lake water residence time. Thus, the overall glacial δ 18Olw-corr level until 21 000 cal BP is consistent with a scenario of weakened or absent SHW at 52° S compared to the present. During the last deglaciation, reconstructed δ 18Olw-corr values reveal a significant two-step rise describing the detailed response of the lake's hydrological balance to this fundamental climatic shift. Rapid warming is seen as the cause of the first rise of ca. 2%, in δ 18Olw-corr during the first two millennia of deglaciation (17 600 to 15 600 cal BP) owing to more 18O enriched precipitation and increasing temperature-induced evaporation. Following this interpretation, an early strengthening of the SHW would not be necessary. The subsequent decrease in δ 18Olw-corr by up to 0.7% marks a millennial-scale transition period between 15 600 and 14 600 cal BP interpreted as the transition from a system driven by temperature-induced evaporation to a system more dominated by wind-induced evaporation. The δ 18Olw-corr record resumes its pronounced increase around 14 600 cal BP. This further cumulative enrichment in 18O of lake water could be interpreted as response to strengthened wind-driven evaporation as induced by the intensification and establishment of the SHW at the latitude of Laguna Potrok Aike (52° S) since 14 600 cal BP. δ 18Olw-corr approaching modern values around 8500 cal BP reflect that the SHW exerted their full influence on the lake water balance at that time provoking a prevailing more arid steppe climate in the Laguna Potrok Aike region. © Author(s) 2014. 资助项目: NSERC, Natural Sciences and Engineering Research Council of Canada
; Natural Sciences and Engineering Research Council of Canada
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49198
Appears in Collections: 气候变化与战略
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Recommended Citation:
Zhu J.,Lücke A.,Wissel H.,et al. Climate history of the Southern Hemisphere Westerlies belt during the last glacial-interglacial transition revealed from lake water oxygen isotope reconstruction of Laguna Potrok Aike (52° S, Argentina)[J]. Climate of the Past,2014-01-01,10(6)