Upper-ocean heat budget and ocean eddy transport in the south-east Pacific in a high-resolution coupled model
Upper-ocean heat budget and ocean eddy transport in the south-east Pacific in a high-resolution coupled model
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DOI：
10.1007/s00382-009-0703-8
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发表时间：
2010-12
期刊：
影响因子：
4.6
通讯作者：
T. Toniazzo;C. Mechoso;L. Shaffrey;J. Slingo
中科院分区：
文献类型：
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作者：
T. Toniazzo;C. Mechoso;L. Shaffrey;J. Slingo
我们提出了一个分析的海洋热平流和它的变化，在东南热带太平洋（100 W-75 W，25 S-10 S）作为模拟的全球耦合模式HiGEM，它具有目前使用的长期积分的最高分辨率之一。模拟的气候学代表了由瞬时小尺度（<450 km）特征引起的温度平流场，其结构和输送似乎与基于20 S，85 W处系泊的可用观测数据的估计一致。瞬变结构非常持久（>4个月），在特定地点，它们对当地海洋上层的热量收支产生重要影响，其特点是规模达几百公里，周期超过一年。然而，这种结构对当地长期海洋热量收支的贡献可能是有迹象的，也可能是消失的，这取决于位置;而且，尽管在活动的优先区域出现了一些组织，但整个区域的平均值很小。虽然有几种不同的机制可能是负责的温度平流的瞬变，我们发现，一个显着的，可能是占主导地位的，组件是与嵌入在大规模的，气候盐度梯度与新鲜入侵的中纬度中间水穿透西北下的热带温跃层的涡旋。
We present an analysis of the oceanic heat advection and its variability in the upper 500 m in the southeastern tropical Pacific (100W–75W, 25S–10S) as simulated by the global coupled model HiGEM, which has one of the highest resolutions currently used in long-term integrations. The simulated climatology represents a temperature advection field arising from transient small-scale (<450 km) features, with structures and transport that appear consistent with estimates based on available observational data for the mooring at 20S, 85W. The transient structures are very persistent (>4 months), and in specific locations they generate an important contribution to the local upper-ocean heat budget, characterised by scales of a few hundred kilometres, and periods of over a year. The contribution from such structures to the local, long-term oceanic heat budget however can be of either sign, or vanishing, depending on the location; and, although there appears some organisation in preferential areas of activity, the average over the entire region is small. While several different mechanisms may be responsible for the temperature advection by transients, we find that a significant, and possibly dominant, component is associated with vortices embedded in the large-scale, climatological salinity gradient associated with the fresh intrusion of mid-latitude intermediate water which penetrates north-westward beneath the tropical thermocline.