Abstract

The heat budget components that are involved in the formation of the tripole structure of the upper mixed layer (UML) temperature anomalies in the North Atlantic under the influence of the North Atlantic Oscillation (NAO) are analyzed using ORA-S3 oceanic reanalysis data for the winter period in 1959–2011. It is shown that the negative UML temperature anomaly in the western part of the tropical zone during the NAO intensification is mainly due to the anomalies of horizontal heat advection and eddy heat diffusion (i.e., nonlocal factors), as well as due to anomalous heat fluxes on the ocean surface (although with a lower significance level). Antiphase changes in the UML temperature in the eastern part of the tropical zone and in the western part of the subtropical zone are accompanied by the anomalies of the heat budget components of the opposite sign. In the subpolar zone, the anomalies of nonlocal components of heat budget also make significant contribution to the UML temperature variation which is in-phase with the one in the tropics. In the high-latitude areas of deep convection, the anomalous heat fluxes at the UML base are also important, and in the eastern part of the subpolar gyre, the anomalies of the net heat fluxes on the ocean surface are crucial too. The signs of the anomalies of the UML heat budget components forming the UML temperature fields in the North Atlantic during the periods with high and low values of the NAO index are opposite.

中文翻译：

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北大西洋涛动对北大西洋混合层热收支的影响

摘要

使用ORA-S3海洋再分析数据分析了北大西洋涛动（NAO）影响下北大西洋上混合层（UML）温度异常的三重结构的形成所涉及的热量收支成分。 1959-2011年的冬季。结果表明，在NAO强化过程中​​，热带带西部UML负温度异常主要是由于水平热对流和涡流热扩散（即非局域因素）异常以及热通量异常引起的。在海洋表面（尽管具有较低的显着性水平）。热带地区东部和亚热带地区西部UML温度的反相位变化伴随着相反符号的热量收支分量的异常。在亚极带中，热量收支的非局部分量的异常也对与热带地区的UML温度变化同相有很大贡献。在深对流的高纬度地区，UML底部的热通量异常也很重要，在亚极回转的东部，海面净热通量的异常也至关重要。在NAO指数高值和低值期间，形成北大西洋UML温度场的UML热收支成分的异常迹象是相反的。热预算中非局部分量的异常也对UML温度变化做出了重要贡献，该温度变化与热带地区的温度同相。在深对流的高纬度地区，UML底部的热通量异常也很重要，在亚极回转的东部，海面净热通量的异常也至关重要。在NAO指数高值和低值期间，形成北大西洋UML温度场的UML热收支成分的异常迹象是相反的。热预算中非局部分量的异常也对UML温度变化做出了重要贡献，该温度变化与热带地区的温度同相。在深对流的高纬度地区，UML底部的热通量异常也很重要，在亚极回转的东部，海面净热通量的异常也至关重要。在NAO指数高值和低值期间，形成北大西洋UML温度场的UML热收支成分的异常迹象是相反的。在亚极回转的东部，海面净热通量的异常也很重要。在NAO指数高值和低值期间，形成北大西洋UML温度场的UML热收支成分的异常迹象是相反的。在亚极回转的东部，海面净热通量的异常也很重要。在NAO指数高值和低值期间，形成北大西洋UML温度场的UML热收支成分的异常迹象是相反的。