DOI: 10.1016/j.quascirev.2014.09.021
Scopus记录号: 2-s2.0-84911922723
论文题名: Late Holocene covariability of the southern westerlies and sea surface temperature in northern Chilean Patagonia
作者: Bertrand S. ; Hughen K. ; Sepúlveda J. ; Pantoja S.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 105 起始页码: 195
结束页码: 208
语种: 英语
英文关键词: Chilean Patagonia
; Fjord sediments
; Inorganic geochemistry
; Paleohydroclimatology
; Paleohydrology
; Southern South America
; Southern westerlies
Scopus关键词: Atmospheric temperature
; Geochemistry
; Sediments
; Submarine geophysics
; Surface properties
; Surface waters
; Inorganic geochemistries
; Paleo-hydrology
; Paleohydroclimatology
; Patagonia
; Southern south america
; Southern westerlies
; Oceanography
; fjord
; grain size
; Holocene
; hydrometeorology
; paleohydrology
; precipitation (climatology)
; proxy climate record
; sea surface temperature
; seasonality
; sediment core
; Southern Hemisphere
; westerly
; Andes
; Chile
; Patagonia
英文摘要: The climate of Chilean Patagonia is strongly influenced by the southern westerlies, which control the amount and latitudinal distribution of precipitation in the southern Andes. In austral summer, the Southern Westerly Wind Belt (SWWB) is restricted to the high latitudes. It expands northward in winter, which results in a strong precipitation seasonality between ~35 and 45°S. Here, we present a new precipitation seasonality proxy record from Quitralco fjord (46°S), where relatively small latitudinal shifts of the SWWB result in large changes in precipitation seasonality. Our 1400yr record is based on sedimentological and geochemical data obtained on a sediment core collected in front of a small river that drains the Patagonian Andes, which makes this site particularly sensitive to changes in river discharge. Our results indicate Fe/Al and Ti/Al values that are low between 600 and 1200CE, increasing at 1200-1500CE, and high between 1500 and 1950CE. Increasing Fe/Al and Ti/Al values reflect a decrease in mean sediment grain-size from 30 to 20μm, which is interpreted as a decrease in seasonal floods resulting from an equatorward shift of the SWWB. Our results suggest that, compared to present-day conditions, the SWWB was located in a more poleward position before 1200CE. It gradually shifted towards the equator in 1200-1500CE, where it remained in a sustained position until 1950CE. This pattern is consistent with most precipitation records from central and southern Chile. The comparison of our record with published regional sea surface temperature (SST) reconstructions for the late Holocene shows that equatorward shifts of the SWWB are systematically coeval with decreasing SSTs and vice versa, which resembles fluctuations over glacial-interglacial timescales. We argue that the synchronicity between SST and SWWB changes during the last 1400 years represents the response of the SWWB to temperature changes in the Southern Hemisphere. © 2014 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60121
Appears in Collections: 过去全球变化的重建
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作者单位: Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA, United States; Renard Centre of Marine Geology, Ghent University, Krijgslaan 281 S8, Gent, Belgium; Department of Geological Sciences and Institute of Arctic and Alpine Research (INSTAAR), University of Colorado Boulder, 450 UCB, Boulder, CO, United States; Department of Oceanography and COPAS-Sur Austral Program, University of Concepción, Barrio Universitario s/n, Concepción, Chile
Recommended Citation:
Bertrand S.,Hughen K.,Sepúlveda J.,et al. Late Holocene covariability of the southern westerlies and sea surface temperature in northern Chilean Patagonia[J]. Quaternary Science Reviews,2014-01-01,105