Surface drifter pair spreading in the North Atlantic
Surface drifter pair spreading in the North Atlantic
复制标题
表面漂流者对在北大西洋扩散
DOI：
10.1029/2010jc006338
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发表时间：
2010
影响因子：
--
通讯作者：
S. Elipot
中科院分区：
文献类型：
--
作者：
R. Lumpkin;S. Elipot
[1]本研究探讨了在墨西哥湾流地区的CLIVAR模式水动力实验（CLIMODE）项目的一部分部署的表面漂流对的传播。的传播是解决每小时的分辨率和量化的相对分散和有限规模的李雅普诺夫指数。在1-3公里到300-500公里的尺度上，色散遵循理查森定律，表明在尺度上与对分离距离相当的涡旋搅动。在更大的尺度上，扩散变成了由恒定扩散率描述的随机游走。从1-3 km到局地形变半径的行为与二维准地转湍流的涡度拟能级联不一致。为了测试这一结果的各种假设，漂移对传播检查对没有一起发射，对部署在北大西洋东部亚热带，和CLIMODE对子采样到每日的时间分辨率。我们的研究结果表明，在墨西哥湾流区的次中尺度的显着能量的存在下，它的波数谱和主导表面搅拌在这个尺度范围内。在能量较低的亚热带东大西洋的结果更加模棱两可。
[1] This study examines spreading of surface drifter pairs deployed as part of the CLIVAR Mode Water Dynamic Experiment (CLIMODE) project in the Gulf Stream region. The spreading is resolved at hourly resolution and quantified by relative dispersion and finite-scale Lyapunov exponents. At scales from 1–3 km to 300–500 km, the dispersion follows Richardson's law, indicating stirring by eddies comparable in scale to the pair separation distance. At larger scales, the spreading becomes a random walk described by a constant diffusivity. The behavior from 1–3 km to the local deformation radius is inconsistent with the enstrophy cascade of 2-D quasigeostrophic turbulence. To test various hypotheses for this result, drifter pair spreading is examined for pairs that were not launched together, pairs deployed in the eastern subtropical North Atlantic, and CLIMODE pairs subsampled to daily temporal resolution. Our results indicate the presence of significant energy at the submesoscale in the Gulf Stream region which flattens the wave number spectrum and dominates surface stirring at this scale range. Results in the less energetic subtropical eastern Atlantic are more equivocal.