气候变化领域集成服务门户(CCPortal): Modulation of Lateral Transport by Submesoscale Flows and Inertia-Gravity Waves

CCPortal

DOI	10.1029/2018MS001508
	Modulation of Lateral Transport by Submesoscale Flows and Inertia-Gravity Waves
	Sinha A.; Balwada D.; Tarshish N.; Abernathey R.
发表日期	2019
ISSN	19422466
起始页码	1039
结束页码	1065
卷号	11 期号:4
英文摘要	We investigate the role of small-scale, high-frequency motions on lateral transport in the ocean, by using velocity fields and particle trajectories from an ocean general circulation model (MITgcm-llc4320) that permits submesoscale flows, inertia-gravity waves, and tides. Temporal averaging/filtering removes most of the submesoscale turbulence, inertia-gravity waves, and tides, resulting in a largely geostrophic flow, with a rapid drop-off in energy at scales smaller than the mesoscales. We advect two types of Lagrangian particles: (a) 2-D particles (surface restricted) and (b) 3-D particles (advected in full three dimensions) with the filtered and unfiltered velocities and calculate Lagrangian diagnostics. At large length/time scales, Lagrangian diffusivity is comparable for filtered and unfiltered velocities, while at short scales, unfiltered velocities disperse particles much faster. We also calculate diagnostics of Lagrangian coherent structures:rotationally coherent Lagrangian vortices detected from closed contours of the Lagrangian-averaged vorticity deviation and material transport barriers formed by ridges of maximum finite-time Lyapunov exponent. For temporally filtered velocities, we observe strong material coherence, which breaks down when the level of temporal filtering is reduced/removed, due to vigorous small-scale mixing. In addition, for the lowest temporal resolution, the 3-D particles experience very little vertical motion, suggesting that degrading temporal resolution greatly reduces vertical advection by high-frequency motions. Our study suggests that Lagrangian diagnostics based on satellite-derived surface geostrophic velocity fields, even with higher spatial resolutions as in the upcoming Surface Water and Ocean Topography mission, may overestimate the presence of mesoscale coherent structures and underestimate dispersion. ©2019. The Authors.
英文关键词	inertia-gravity waves; Lagrangian coherent structures; Lagrangian diffusivity; submesoscale turbulence; tides; vertical motion
语种	英语
scopus关键词	Gravity waves; Lyapunov methods; Surface waters; Tides; Topography; Turbulence; Velocity; Finite-time Lyapunov exponent; Geostrophic velocity fields; Inertia gravity waves; Lagrangian; Lagrangian coherent structures; Ocean general circulation models; Particle trajectories; Vertical motions; Lagrange multipliers; advection; general circulation model; gravity wave; mesoscale eddy; oceanic general circulation model; satellite mission; spatial resolution; turbulence; vertical movement
来源期刊	Journal of Advances in Modeling Earth Systems
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156927
作者单位	Applied Physics and Applied Mathematics Department, Columbia University, New York, NY, United States; Courant Institute of Mathematical Sciences, New York University, New York, NY, United States; Atmospheric and Oceanic Sciences Program, Princeton University, Princeton, NJ, United States; Department of Earth and Environmental Sciences, Columbia University, New York, NY, United States
推荐引用方式 GB/T 7714	Sinha A.,Balwada D.,Tarshish N.,et al. Modulation of Lateral Transport by Submesoscale Flows and Inertia-Gravity Waves[J],2019,11(4).
APA	Sinha A.,Balwada D.,Tarshish N.,&Abernathey R..(2019).Modulation of Lateral Transport by Submesoscale Flows and Inertia-Gravity Waves.Journal of Advances in Modeling Earth Systems,11(4).
MLA	Sinha A.,et al."Modulation of Lateral Transport by Submesoscale Flows and Inertia-Gravity Waves".Journal of Advances in Modeling Earth Systems 11.4(2019).