DOI: 10.1038/ngeo2365
论文题名: Steering of westerly storms over western North America at the Last Glacial Maximum
作者: Oster J.L. ; Ibarra D.E. ; Winnick M.J. ; Maher K.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2015
卷: 8, 期: 3 起始页码: 201
结束页码: 205
语种: 英语
Scopus关键词: ablation
; desiccation
; Last Glacial Maximum
; Laurentide Ice Sheet
; wind direction
; Aleutian Margin
; Pacific Ocean
; United Kingdom
英文摘要: The hydroclimate history of North America includes the formation and desiccation of large inland lakes and the growth and ablation of glaciers throughout the Quaternary period. At the Last Glacial Maximum, expanded pluvial lakes in the south and aridity in the northwest suggest that the winter westerly storm track was displaced southwards and migrated northwards as the Laurentide Ice Sheet waned. However, lake highstands do not occur synchronously along zonal bands, in conflict with this hypothesis. Here we compile a network of precipitation proxy reconstructions from lakes, speleothems, groundwater deposits, packrat middens and glaciers from the western and southwestern US, which we compare with an ensemble of climate simulations to identify the controls of regional hydroclimatic change. The proxy records suggest a precipitation dipole during the Last Glacial Maximum, with wetter than modern conditions in the southwest and drier conditions near the ice sheet, and a northwest-southeast trending transition zone across the northern Great Basin. The models that simulate a weaker and south-shifted Aleutian low-pressure system, a strong North Pacific high-pressure system, and a high above the ice sheet best reproduce this regional variation. We therefore conclude that rather than a uniformly south-shifted storm track, a stronger jet that is squeezed and steered across the continent by high-pressure systems best explains the observed regional hydroclimate patterns of the Last Glacial Maximum. © 2015 Macmillan Publishers Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106343
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN, United States; Department of Environmental Earth System Science, Stanford University, Stanford, CA, United States; Department of Geological and Environmental Sciences, Stanford University, Stanford, CA, United States
Recommended Citation:
Oster J.L.,Ibarra D.E.,Winnick M.J.,et al. Steering of westerly storms over western North America at the Last Glacial Maximum[J]. Nature Geoscience,2015-01-01,8(3)