Ocean mesoscale mixing linked to climate variability
Ocean mesoscale mixing linked to climate variability
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DOI：
10.1126/sciadv.aav5014
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发表时间：
2019-01-01
期刊：
影响因子：
13.6
通讯作者：
Abernathey, Ryan P.
中科院分区：
文献类型：
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作者：
Busecke, Julius J. M.;Abernathey, Ryan P.
海洋中的中尺度湍流强烈影响环流、水团形成和示踪剂的运输。然而，人们对混合如何随气候时间尺度变化知之甚少。我们提出了第一个时间分辨的海洋表面横向中尺度涡流扩散率的全球数据集，该数据集是通过将抑制混合长度理论应用于卫星观测的速度而获得的。我们发现全球海洋的年际变化与 ENSO、NAO、DMI 和 PDO 等气候指数存在区域相关性。由大规模流动的变化驱动的混合长度的变化通常超过局部涡流动能变化的影响，局部涡流动能先前被认为是涡流混合变化的主要驱动因素。这一机制目前尚未在全球气候模型中体现，但可能会对全球海洋中热量、盐和碳的分布以及生态系统动态和区域动态（例如 ENSO 方差）产生深远的影响。
Mesoscale turbulence in the ocean strongly affects the circulation, water mass formation, and transport of tracers. Little is known, however, about how mixing varies on climate timescales. We present the first time-resolved global dataset of lateralmesoscale eddy diffusivities at the ocean surface, obtainedbyapplying thesuppressedmixing length theory to satellite-observed velocities. We find interannual variability throughout the global ocean, regionally correlated with climate indices such as ENSO, NAO, DMI, and PDO. Changes in mixing length, driven by variations in the large-scale flow, often exceed the effect of variations in local eddy kinetic energy, previously thought of as the primary driver of variability in eddy mixing. This mechanism, not currently represented in global climate models, could have far-reaching consequences for the distribution of heat, salt, and carbon in the global ocean, as well as ecosystem dynamics and regional dynamics such as ENSO variance.