气候变化领域集成服务门户(CCPortal): Relative Dispersion of Surface Drifters in the North Sea: The Effect of Tides on Mesoscale Diffusivity

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DOI	10.1029/2019JC015925
	Relative Dispersion of Surface Drifters in the North Sea: The Effect of Tides on Mesoscale Diffusivity
	Meyerjürgens J.; Ricker M.; Schakau V.; Badewien T.H.; Stanev E.V.
发表日期	2020
ISSN	21699275
卷号	125 期号:8
英文摘要	We examine the relative dispersion and the contribution of tides on the relative diffusivities of surface drifters in the North Sea. The drifters are released in two clusters, yielding 43 pairs, in the vicinity of a tidal mixing front in the German Bight, which is located in the southeastern area of the North Sea. Both clusters indicate decreasing dispersion when crossing the tidal mixing front, followed by exponentially increasing dispersion with e-folding times of 0.5 days for Cluster 1 and 0.3 days for Cluster 2. A transition of the dispersion regimes is observed at scales of the order of the Rossby radius of deformation (10 km). After that, the relative dispersion grows with a power-law dependency with a short period of ballistic dispersion (quadratic growth), followed by a Richardson regime (cubic growth) in the final phase. Scale-dependent metrics such as the relative diffusivities are consistent with these findings, while the analysis of the finite-scale Lyapunov exponents (FSLEs) shows contradictory results for the submesoscales. In summary, the analysis of various statistical Lagrangian metrics suggests that tracer stirring at the submesoscales is nonlocal and becomes local at separation scales larger than 10 km. The analysis of meridional and zonal dispersion components indicates anisotropic dispersion at the submesoscales, which changes into isotropic dispersion on the mesoscales. Spectral analysis of the relative diffusivity gives evidence that semidiurnal and shallow-water tides influence relative diffusivity at the mesoscales, especially for drifter separations above 50 km. ©2020. The Authors.
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186754
作者单位	Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Oldenburg, Germany; Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany
推荐引用方式 GB/T 7714	Meyerjürgens J.,Ricker M.,Schakau V.,et al. Relative Dispersion of Surface Drifters in the North Sea: The Effect of Tides on Mesoscale Diffusivity[J],2020,125(8).
APA	Meyerjürgens J.,Ricker M.,Schakau V.,Badewien T.H.,&Stanev E.V..(2020).Relative Dispersion of Surface Drifters in the North Sea: The Effect of Tides on Mesoscale Diffusivity.Journal of Geophysical Research: Oceans,125(8).
MLA	Meyerjürgens J.,et al."Relative Dispersion of Surface Drifters in the North Sea: The Effect of Tides on Mesoscale Diffusivity".Journal of Geophysical Research: Oceans 125.8(2020).