Seasonality in submesoscale turbulence.
Seasonality in submesoscale turbulence.
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DOI：
10.1038/ncomms7862
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发表时间：
2015-04-21
影响因子：
16.6
通讯作者：
Gula J
中科院分区：
文献类型：
--
作者：
Callies J;Ferrari R;Klymak JM;Gula J
尽管最强的海洋表面流发生在水平尺度上，大约100 公里，但最近的数值模拟表明，比这些中尺度涡旋更小的流动可以在上层海洋实现重要的垂直输送。这些水平范围为1-100 公里的亚中尺度气流将热量和大气气体带到海洋内部，加速了海-气通量，并将深层营养物质带到阳光照耀的表层，为初级生产提供了燃料。在这里，我们提出了次中尺度气流在地面混合层中经历季节性循环的观测证据：它们在冬季比夏季强得多。在水平尺度1-10 Km的深冬混合层中，围绕地转涡发展的斜压不稳定为次中尺度气流提供能量。大于此不稳定尺度的流动由湍流尺度相互作用提供能量。冬季混合层中次中尺度活动的增强有望实现与下方永久温跃层的有效交换。最近的数值模拟表明，沿海洋涡旋边缘发展的锋面在冬季比夏季更强。在这里，作者提出了观测证实，它告诉我们这些锋面流是如何形成的。
Although the strongest ocean surface currents occur at horizontal scales of order 100 km, recent numerical simulations suggest that flows smaller than these mesoscale eddies can achieve important vertical transports in the upper ocean. These submesoscale flows, 1–100 km in horizontal extent, take heat and atmospheric gases down into the interior ocean, accelerating air–sea fluxes, and bring deep nutrients up into the sunlit surface layer, fueling primary production. Here we present observational evidence that submesoscale flows undergo a seasonal cycle in the surface mixed layer: they are much stronger in winter than in summer. Submesoscale flows are energized by baroclinic instabilities that develop around geostrophic eddies in the deep winter mixed layer at a horizontal scale of order 1–10 km. Flows larger than this instability scale are energized by turbulent scale interactions. Enhanced submesoscale activity in the winter mixed layer is expected to achieve efficient exchanges with the permanent thermocline below. Recent numerical simulations suggest that the fronts that develop along the rims of ocean eddies are stronger in winter than in summer. Here, the authors present observational confirmation, which informs how these frontal flows are formed.
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影响因子：
3.5
作者：
Boccaletti, Giulio;Ferrari, Raffaele;Fox-Kemper, Baylor
通讯作者：
Fox-Kemper, Baylor
影响因子：
3.5
作者：
Capet, X.;Mcwilliams, J. C.;Shchepetkin, A. F.
通讯作者：
Shchepetkin, A. F.
影响因子：
3.6
作者：
Dong, Shenfu;Sprintall, Janet;Talley, Lynne
通讯作者：
Talley, Lynne
影响因子：
3.7
作者：
HELD, IM;PIERREHUMBERT, RT;SWANSON, KL
通讯作者：
SWANSON, KL
影响因子：
3.6
作者：
Ferrari, R;Rudnick, DL
通讯作者：
Rudnick, DL