DOI: 10.5194/cp-9-903-2013
Scopus记录号: 2-s2.0-84881227465
论文题名: Stable isotopic evidence of El Ni no-like atmospheric circulation in the Pliocene western United States
作者: Winnick M.J. ; Welker J.M. ; Chamberlain C.P.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2013
卷: 9, 期: 2 起始页码: 9
结束页码: 12
语种: 英语
Scopus关键词: atmospheric circulation
; El Nino
; El Nino-Southern Oscillation
; ice sheet
; isotopic analysis
; Northern Hemisphere
; Pliocene
; precipitation (chemistry)
; proxy climate record
; subtropical region
; temperature effect
; United States
英文摘要: Understanding how the hydrologic cycle has responded to warmer global temperatures in the past is especially important today as concentrations of CO2 in the atmosphere continue to increase due to human activities. The Pliocene offers an ideal window into a climate system that has equilibrated with current atmospheric pCO2. During the Pliocene the western United States was wetter than modern, an observation at odds with our current understanding of future warming scenarios, which involve the expansion and poleward migration of the subtropical dry zone. Here we compare Pliocene oxygen isotope profiles of pedogenic carbonates across the western US to modern isotopic anomalies in precipitation between phases of the El Nino-Southern Oscillation (ENSO). We find that when accounting for seasonality of carbonate formation, isotopic changes through the late Pliocene match modern precipitation isotopic anomalies in El Nino years. Furthermore, isotopic shifts through the late Pliocene mirror changes through the early Pleistocene, which likely represents the southward migration of the westerly storm track caused by growth of the Laurentide ice sheet. We propose that the westerly storm track migrated northward through the late Pliocene with the development of the modern cold tongue in the east equatorial Pacific, then returned southward with widespread glaciation in the Northern Hemisphere-a scenario supported by terrestrial climate proxies across the US. Together these data support the proposed existence of background El Nino-like conditions in western North America during the warm Pliocene. If the earth behaves similarly with future warming, this observation has important implications with regard to the amount and distribution of precipitation in western North America.© 2013 Author(s). 资助项目: NSF, National Science Foundation
; NSF, National Science Foundation
; NSF, National Science Foundation
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49419
Appears in Collections: 气候变化与战略
There are no files associated with this item.
Recommended Citation:
Winnick M.J.,Welker J.M.,Chamberlain C.P.. Stable isotopic evidence of El Ni no-like atmospheric circulation in the Pliocene western United States[J]. Climate of the Past,2013-01-01,9(2)