Interannual variability of the Guinea Dome and its possible link with the Atlantic Meridional Mode
Interannual variability of the Guinea Dome and its possible link with the Atlantic Meridional Mode
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DOI：
10.1007/s00382-009-0574-z
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发表时间：
2009-12-01
期刊：
影响因子：
4.6
通讯作者：
Yamagata, Toshio
中科院分区：
文献类型：
--
作者：
Doi, Takeshi;Tozuka, Tomoki;Yamagata, Toshio
利用NCEP/NCAR再分析资料强迫的高分辨率海洋环流模式，从与热带辐合带（ITCZ）经向迁移有关的大西洋经向模态（AMM）的可能联系的新观点研究了几内亚巨球的年际变率。由于风致Ekman上升流的影响，达喀尔附近的圆顶在春末至秋末季节性地发育；它的季节演变与北移有关。当ITCZ在春末夏初异常北（南）向时，由于北半球的风-蒸发-海温正反馈和海温正（负）异常，秋季由于Ekman上升流增强（减弱），穹状体变得异常强（弱）。这可能会导致AMM的衰退。因此，AMM和几内亚巨蛋之间的耦合性质对于理解、模拟和预测热带大西洋变率很重要。
Using a high-resolution ocean general circulation model forced by NCEP/NCAR reanalysis data, the interannual variability of the Guinea Dome is studied from a new viewpoint of its possible link with the Atlantic Meridional Mode (AMM), which is related to the meridional migration of the Intertropical Convergence Zone (ITCZ). The dome develops off Dakar seasonally from late spring to late fall owing to the wind-induced Ekman upwelling; its seasonal evolution is associated with the northward migration of the ITCZ. When the ITCZ is located anomalously northward (southward) from late spring to early summer, as a result of the wind-evaporation-sea surface temperature (SST) positive feedback with positive (negative) SST anomaly over the Northern Hemisphere, the dome becomes unusually strong (weak) in fall as a result of stronger (weaker) Ekman upwelling. This may contribute to the decay of the AMM. Thus, the coupled nature between the AMM and the Guinea Dome could be important in understanding, modeling, and predicting the tropical Atlantic variability.