| DOI: | 10.1007/s00382-017-3701-2
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| Scopus记录号: | 2-s2.0-85018341862
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| 论文题名: | Main processes of the Atlantic cold tongue interannual variability |
| 作者: | Planton Y.; Voldoire A.; Giordani H.; Caniaux G.
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| 刊名: | Climate Dynamics
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| ISSN: | 9307575
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| 出版年: | 2018
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| 卷: | 50, 期:2018-05-06 | | 起始页码: | 1495
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| 结束页码: | 1512
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| 语种: | 英语
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| 英文关键词: | Atlantic cold tongue
; Equatorial Atlantic
; Interannual variability
; Mixed-layer heat budget
; Oceanic mixed-layer processes
; Vertical mixing
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| Scopus关键词: | annual variation
; cooling
; general circulation model
; heat budget
; mixed layer
; sea surface temperature
; temperature anomaly
; vertical mixing
; Atlantic Ocean
; Atlantic Ocean (Equatorial)
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| 英文摘要: | The interannual variability of the Atlantic cold tongue (ACT) is studied by means of a mixed-layer heat budget analysis. A method to classify extreme cold and warm ACT events is proposed and applied to ten various analysis and reanalysis products. This classification allows 5 cold and 5 warm ACT events to be selected over the period 1982–2007. Cold (warm) ACT events are defined by the presence of negative (positive) sea surface temperature (SST) anomalies at the center of the equatorial Atlantic in late boreal spring, preceded by negative (positive) zonal wind stress anomalies in the western equatorial Atlantic. An ocean general circulation model capable of reconstructing the interannual variability of the ACT correctly is used to demonstrate that cold ACT events develop rapidly from May to June mainly due to intense cooling by vertical mixing and horizontal advection. The simulated cooling at the center of the basin is the result of the combined effects of non-local and local processes. The non-local process is an upwelling associated with an eastward-propagating Kelvin wave, which makes the mixed-layer more shallow and preconditions the upper layers to be cooled by an intense heat loss at the base of the mixed-layer, which is amplified by a stronger local injection of energy from the atmosphere. The early cooling by vertical mixing in March is also shown to be a good predictor of June cooling. In July, horizontal advection starts to warm the mixed-layer abnormally and damps SST anomalies. The advection anomalies, which result from changes in the horizontal temperature gradient, are associated in some cases with the propagation of Rossby waves along the equator. During warm ACT events, processes are reversed, generating positive SST anomalies: a downwelling Kelvin wave triggers stratification anomalies and mixed-layer depth anomalies, amplified by a weaker injection of energy from the atmosphere in May–June. In July, warm ACT events are abnormally cooled due to negative horizontal advection anomalies resulting from processes similar to those that occur during cold ACT events. This additional cooling process extends the period of cooling of the ACT, reducing SST anomalies. © 2017, Springer-Verlag Berlin Heidelberg. |
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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/109414
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| Appears in Collections: | 影响、适应和脆弱性
气候变化事实与影响
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作者单位: | CNRM-UMR3589, Météo-France/CNRS, CNRM, Toulouse, France
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| Recommended Citation: | |
Planton Y.,Voldoire A.,Giordani H.,et al. Main processes of the Atlantic cold tongue interannual variability[J]. Climate Dynamics,2018-01-01,50(2018-05-06)
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