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| DOI | 10.1029/2019JC016003 |
| Why Do Benguela Niños Lead Atlantic Niños? | |
| Illig S.; Bachèlery M.-L.; Lübbecke J.F. | |
| 发表日期 | 2020 |
| ISSN | 21699275 |
| 卷号 | 125期号:9 |
| 英文摘要 | We investigate the lag between warm interannual Sea Surface Temperature (SST) events in the eastern-equatorial Atlantic, the Atlantic Niños, and the occurrence of Benguela Niños along the southwestern Angolan coast. While it is commonly agreed that both events are associated with equatorial and subsequent coastal-trapped wave propagations driven remotely by a relaxation of the trade-winds, it is surprising that SST anomalies off Angola tend to precede the ones in the eastern-equatorial sector by ~1 month. To explain this counterintuitive behavior, our methodology is based on the experimentation with a Tropical Atlantic Ocean model. Using idealized wind-stress perturbations from a composite analysis, we trigger warm equatorial and coastal events over a stationary and then, seasonally varying ocean mean-state. In agreement with the linear dynamics, our results show that when the interannual wind-stress forcing is restricted to the western-central equatorial Atlantic, the model yields equatorial events leading the coastal ones. This implies that neither the differences in the ocean stratification between the two regions (thermocline depths or modal wave contributions) nor the seasonal phasing of the events explains the observed temporal sequence. Only if wind-stress anomalies are also prescribed in the coastal fringe, the coastal warming precedes the eastern-equatorial SST anomaly peak, emphasizing the role of the local forcing in the phenology of Benguela Niños. A weaker South-Atlantic Anticyclone initiates the coastal warming before the development of eastern-equatorial SST anomalies. Then, equatorward coastal wind anomalies, driven by a convergent anomalous circulation located on the warm Atlantic Niño, stop the remotely forced coastal warming prematurely. ©2020. American Geophysical Union. All Rights Reserved. |
| 英文关键词 | Atlantic and Benguela Niños; interannual SST variability; ocean model; ocean-atmosphere interactions; tropical Atlantic; wave propagations |
| 语种 | 英语 |
| 来源期刊 | Journal of Geophysical Research: Oceans
 |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/186681 |
| 作者单位 | Laboratoire d'Etudes en Géophysique et Océanographie Spatiale (LEGOS), CNRS/IRD/UPS/CNES, Toulouse, France; Department of Oceanography, MARE Institute, LMI ICEMASA, University of Cape Town, Cape Town, South Africa; Nansen-Tutu Centre, Marine Research Institute, Department of Oceanography, University of Cape Town, Cape Town, South Africa; Research Division Ocean Circulation and Climate Dynamics, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany; Faculty of Mathematics and Natural Sciences, Christian-Albrechts-Universität zu Kiel, Kiel, Germany |
| 推荐引用方式 GB/T 7714 | Illig S.,Bachèlery M.-L.,Lübbecke J.F.. Why Do Benguela Niños Lead Atlantic Niños?[J],2020,125(9). |
| APA | Illig S.,Bachèlery M.-L.,&Lübbecke J.F..(2020).Why Do Benguela Niños Lead Atlantic Niños?.Journal of Geophysical Research: Oceans,125(9). |
| MLA | Illig S.,et al."Why Do Benguela Niños Lead Atlantic Niños?".Journal of Geophysical Research: Oceans 125.9(2020). |
| 条目包含的文件 | 条目无相关文件。 | |||||
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