Interannual atmospheric variability forced by the deep equatorial Atlantic Ocean
Interannual atmospheric variability forced by the deep equatorial Atlantic Ocean
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赤道大西洋深部造成的大气年际变化
作者：
Brandt;A. Funk;V. Hormann;M. Dengler;R. Greatbatch;J. Toole
热带大西洋的气候变化是由大规模的海洋-大气相互作用决定的，特别是影响海洋和周围大陆的深层大气对流。除了太平洋厄尔尼诺/南方涛动和北大西洋涛动的影响外，热带大西洋变率被认为是由两种不同的海洋-大气耦合变率模式主导，这两种模式以经向和纬向海面温度梯度为特征，分别主要活跃于年代际和年际时间尺度。在这里，我们报告的证据表明，赤道大西洋深处的内在海洋动力学也会影响热带大西洋地区的海面温度、风和降雨，并构成4.5年的气候周期。具体来说，在大西洋深处观察到垂直交替的短垂直波长的深部带状急流，周期约为 4.5 年，振幅超过 10 cms−1，向上传播能量，向表面传播。它们在海面与赤道纬向流异常和东大西洋温度异常相关，其振幅分别约为 6cms−1 和 0.4℃，并与不同的风和降雨模式相关。尽管在太平洋和印度洋也观察到了深层急流，但只有大西洋深层急流似乎在年际时间尺度上振荡。我们对这些喷流的持久性和规律性的了解受到高质量数据可用性的限制。尽管有这样的警告，振荡行为仍然可以用来改进热带大西洋海面温度的预测。通过赤道暗流产生深射流和向上传输能量值得进一步的理论研究。
Climate variability in the tropical Atlantic Ocean is determined by large-scale ocean–atmosphere interactions, which particularly affect deep atmospheric convection over the ocean and surrounding continents. Apart from influences from the Pacific El Niño/Southern Oscillation and the North Atlantic Oscillation, the tropical Atlantic variability is thought to be dominated by two distinct ocean–atmosphere coupled modes of variability that are characterized by meridional,and zonal,sea-surface-temperature gradients and are mainly active on decadal and interannual timescales, respectively,. Here we report evidence that the intrinsic ocean dynamics of the deep equatorial Atlantic can also affect sea surface temperature, wind and rainfall in the tropical Atlantic region and constitutes a 4.5-yr climate cycle. Specifically, vertically alternating deep zonal jets of short vertical wavelength with a period of about 4.5 yr and amplitudes of more than 10 cm s−1are observed, in the deep Atlantic, to propagate their energy upwards, towards the surface,. They are linked, at the sea surface, to equatorial zonal current anomalies and eastern Atlantic temperature anomalies that have amplitudes of about 6 cm s−1and 0.4 °C, respectively, and are associated with distinct wind and rainfall patterns. Although deep jets are also observed in the Pacific and Indian oceans, only the Atlantic deep jets seem to oscillate on interannual timescales. Our knowledge of the persistence and regularity of these jets is limited by the availability of high-quality data. Despite this caveat, the oscillatory behaviour can still be used to improve predictions of sea surface temperature in the tropical Atlantic. Deep-jet generation and upward energy transmission through the Equatorial Undercurrent warrant further theoretical study.
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DOI：
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发表时间：
1986
期刊：
影响因子：
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作者：
M. Mcphaden;J. A. Proehl;L. Rothstein
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DOI：
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发表时间：
2002
期刊：
影响因子：
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DOI：
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发表时间：
2007
期刊：
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作者：
G. L. Brown;B. Sutherland
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影响因子：
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作者：
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DOI：
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发表时间：
1981
期刊：
影响因子：
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作者：
S. Philander;R. Pacanowski
通讯作者：
R. Pacanowski