The role of vertical eddy flux in Southern Ocean heat uptake
The role of vertical eddy flux in Southern Ocean heat uptake
复制标题
垂直涡通量在南大洋吸热中的作用
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
P. Spence
中科院分区：
文献类型：
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作者：
A. Morrison;O. Saenko;A. Hogg;P. Spence
在一个理想化的允许涡旋的海洋模式中，研究了改变垂直涡旋热通量对南大洋热吸收的作用。增强的海气热通量驱动了深层的南方变暖，这是由于等密度纬向温度梯度的减小，因此减少了向上的涡动热通量。这种机制是定性相似的模型，无论是允许的或参数化的涡流，由于其依赖于等密度温度梯度，而不是动态响应的涡流场。相比之下，增加的风应力通过增强涡动场和由此产生的涡动热发散驱动南大洋中层冷却。瞬态冷却持续数十年，而平均流量调整以平衡更快的涡流响应。这种由风驱动的冷却机制还没有被具有固定涡旋参数化的粗分辨率模式捕获，并且是最近在南大洋观察到的冷却的可能候选者。
The role of changing vertical eddy heat flux on Southern Ocean heat uptake is investigated in an idealized eddy‐permitting ocean model. Enhanced air‐sea heat flux drives deep‐reaching southern warming, due to a reduction in the isopycnal meridional temperature gradient and therefore decreased upward eddy heat flux. This mechanism is qualitatively similar in models with either permitted or parameterized eddies, due to its dependence on the isopycnal temperature gradient rather than the dynamical response of the eddy field. In contrast, increased wind stress drives mid‐depth Southern Ocean cooling through an enhancement of the eddy field and resultant eddy heat divergence. The transient cooling extends over multiple decades while the mean flow adjusts to balance the faster eddy response. This wind‐driven cooling mechanism has not been captured by coarse resolution models with fixed eddy parameterizations and is a possible candidate for the recent cooling observed in the Southern Ocean.