DOI: 10.1175/JCLI-D-17-0314.1
Scopus记录号: 2-s2.0-85040923656
论文题名: Northern westerlies during the last glacial maximum: Results from CMIP5 simulations
作者: Wang N. ; Jiang D. ; Lang X.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2018
卷: 31, 期: 3 起始页码: 1135
结束页码: 1153
语种: 英语
英文关键词: Atmospheric circulation
; Climate models
; Ice age
; Paleoclimate
Scopus关键词: Glacial geology
; Troposphere
; Atmospheric circulation
; Baroclinic instability
; Coupled Model Intercomparison Project
; Ice age
; Laurentide ice sheets
; Mediterranean region
; Paleoclimates
; Regional characteristics
; Climate models
; atmospheric circulation
; climate modeling
; CMIP
; ice sheet
; jet stream
; Last Glacial Maximum
; Northern Hemisphere
; paleoclimate
; westerly
; Mediterranean Region
; North America
; Pacific Ocean
; Pacific Ocean (North)
英文摘要: Based upon simulations from phase 5 of the Coupled Model Intercomparison Project (CMIP5), the vertical and regional characteristics of the northern westerlies during the Last Glacial Maximum (LGM) are investigated in this study. At the Northern Hemispheric scale, all nine available models simulate a poleward shift of the 200-hPa jet, and eight models simulate an equatorward shift of the 850-hPa jet compared to the preindustrial period; these shifts are of approximately 2°-3° latitude for the arithmetic multimodel mean. The upper-tropospheric cooling in the tropics, possibly due to reduced latent heat release, is expected to account for the poleward shift of the 200-hPa jet through the thermal wind relationship. Changes in the midlatitude baroclinic instability in response to the amplified polar cooling are associated with the jet stream in the lower troposphere through anomalous eddy activity. In particular, the types of predominant baroclinic eddies are regionally dependent. The behavior of the 850-hPa jet over the North Pacific is steered by transient eddies and characterized by a southward displacement during the LGM. By contrast, the remarkable enhancement of the North Atlantic jet stream throughout the troposphere is associated with the notably increased stationary eddy momentum convergence, presumably due to the presence of the Laurentide ice sheet over North America. In comparison with the proxy records, although there is no observational evidence explicitly indicating changes of the upper-level northern westerlies, the simulated LGM 850-hPa westerly wind field is indirectly concordant with the reconstructed moisture conditions over the Mediterranean region and southwestern North America. © 2018 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/111674
Appears in Collections: 气候减缓与适应
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作者单位: Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China; Joint Laboratory for Climate and Environmental Change, Chengdu University of Information Technology, Chengdu, China; Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences, University of Chinese Academy of Sciences, Beijing, China; Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, China; Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing, China
Recommended Citation:
Wang N.,Jiang D.,Lang X.. Northern westerlies during the last glacial maximum: Results from CMIP5 simulations[J]. Journal of Climate,2018-01-01,31(3)