| DOI: | 10.1175/JCLI-D-17-0118.1
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| Scopus记录号: | 2-s2.0-85043238575
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| 论文题名: | Regime change behavior during Asian monsoon onset |
| 作者: | Geen R.; Lambert F.H.; Vallis G.K.
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| 刊名: | Journal of Climate
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| ISSN: | 8948755
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| 出版年: | 2018
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| 卷: | 31, 期:8 | | 起始页码: | 3327
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| 结束页码: | 3348
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| 语种: | 英语
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| 英文关键词: | Climate classification/regimes
; Dynamics
; Hadley circulation
; Intertropical convergence zone
; Monsoons
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| Scopus关键词: | Budget control
; Cells
; Cytology
; Dynamics
; Vorticity
; Absolute vorticity
; Climate classification/regimes
; Hadley circulation
; Intertropical convergence zone
; Monsoons
; Overturning circulation
; Primitive equations
; Southern Hemisphere
; Atmospheric thermodynamics
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| 英文摘要: | As the ITCZ moves off the equator on an aquaplanet, the Hadley circulation transitions from an equinoctial regime with two near-symmetric, significantly eddy-driven cells to a monsoon-like regime with a strong, thermally direct cross-equatorial cell, intense low-latitude precipitation, and a weak summer hemisphere cell. Dynamical feedbacks appear to accelerate the transition. This study investigates the relevance of this behavior to monsoon onset by using primitive equation model simulations ranging from aquaplanets to more realistic configurations with Earth's continents and topography. A change in the relationship between ITCZ latitude and overturning strength is identified once the ITCZ moves poleward of approximately 7°. Monsoon onset is associated with off-equatorial ascent in regions of nonnegligible planetary vorticity, and this is found to generate a vortex stretching tendency that reduces upper-level absolute vorticity. In an aquaplanet, this causes a transition to the cross-equatorial, thermally direct regime, intensifying the overturning circulation. Analysis of the zonal momentum budget suggests that a stationary wave, driven by topography and land-sea contrast, can trigger a similar transition in the more realistic model configuration, with the wave extending the ascent region of the Southern Hemisphere Hadley cell northward, and enhanced overturning then developing to the south. These two elements of the circulation resemble the East and South Asian monsoons. © 2018 American Meteorological Society. |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/111580
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| Appears in Collections: | 气候减缓与适应
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作者单位: | College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom
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| Recommended Citation: | |
Geen R.,Lambert F.H.,Vallis G.K.. Regime change behavior during Asian monsoon onset[J]. Journal of Climate,2018-01-01,31(8)
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