DOI: 10.1175/JCLI-D-14-00140.1
Scopus记录号: 2-s2.0-84907573448
论文题名: Role of changes in mean temperatures versus temperature gradients in the recent widening of the Hadley circulation
作者: Adam O. ; Schneider T. ; Harnik N.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2014
卷: 27, 期: 19 起始页码: 7450
结束页码: 7461
语种: 英语
Scopus关键词: Atmospheric circulation
; Climate sensitivity
; ENSO
; Hadley circulation
; Reanalysis
; annual variation
; atmospheric circulation
; climate change
; El Nino-Southern Oscillation
; global warming
; Hadley cell
; temperature gradient
英文摘要: The Hadley circulation (HC) has widened in recent decades, and it widens as the climate warms in simulations. But the mechanisms responsible for the widening remain unclear, and the widening in simulations is generally smaller than observed. To identify mechanisms responsible for the HC widening and for model-observation discrepancies, this study analyzes how interannual variations of tropical-mean temperatures and meridional temperature gradients influence the HC width. Changes in mean temperatures are part of any global warming signal, whereas changes in temperature gradients are primarily associated with ENSO. Within this study, 6 reanalysis datasets, 22 Atmospheric Modeling Intercomparison Project (AMIP) simulations, and 11 historical simulations from phase 5 of the Climate Modeling Intercomparison Project (CMIP5) are analyzed, covering the years 1979-2012. It is found that the HC widens as mean temperatures increase or as temperature gradients weaken in most reanalyses and climate models. On average, climate models exhibit a smaller sensitivity ofHC width to changes in mean temperatures and temperature gradients than do reanalyses. However, the sensitivities differ substantially among reanalyses, rendering the HC response to mean temperatures in climate models not statistically different from that in reanalyses. While global-mean temperatures did not increase substantially between 1997 and 2012, the HC continued to widen in most reanalyses. The analysis here suggests that the HC widening from 1979 to 1997 is primarily the result of global warming, whereas the widening of the HC from 1997 to 2012 is associated with increased midlatitude temperatures and hence reduced temperature gradients during this period. © 2014 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/51109
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Earth Sciences, Eidgenössische Technische Hochschule Zürich, Zurich, Switzerland; California Institute of Technology, Pasadena, CA, United States; Department of Geosciences, Tel Aviv University, Tel Aviv, Israel
Recommended Citation:
Adam O.,Schneider T.,Harnik N.. Role of changes in mean temperatures versus temperature gradients in the recent widening of the Hadley circulation[J]. Journal of Climate,2014-01-01,27(19)