Steepest ascent low/non-low frequency ratio in empirical mode decomposition to separate deterministic and stochastic velocities from a single Lagrangian drifter
Loading...
Files
Authors
Chu, Peter C.
Subjects
Advisors
Date of Issue
2018
Date
Publisher
AGU Publications
Language
Abstract
SOund Fixing And Ranging (RAFOS) floats deployed by the Naval Postgraduate School (NPS) in 4 the California Current system from 1992 to 2001 at depth between 150 and 600 m (http://www.oc.nps.edu/ 5 npsRAFOS/) are used to study 2-D turbulent characteristics. Each drifter trajectory is adaptively decomposed 6 using the empirical mode decomposition (EMD) into a series of intrinsic mode functions (IMFs) with corre- 7 sponding specific scale for each IMF. A new steepest ascent low/non-low-frequency ratio is proposed in this 8 paper to separate a Lagrangian trajectory into low-frequency (nondiffusive, i.e., deterministic) and high- 9 frequency (diffusive, i.e., stochastic) components. The 2-D turbulent (or called eddy) diffusion coefficients 10 are calculated on the base of the classical turbulent diffusion with mixing length theory from stochastic 11 component of a single drifter. Statistical characteristics of the calculated 2-D turbulence length scale, 12 strength, and diffusion coefficients from the NPS RAFOS data are presented with the mean values (over the 13 whole drifters) of the 2-D diffusion coefficients comparable to the commonly used diffusivity tensor method.
Type
Article
Description
The article of record as published may be found at http://dx.doi.org/10.1002/2017JC013500
Series/Report No
Department
Oceanography
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
Chu, P. C. (2018). Steepest ascent low/non-low-frequency ratio in empirical mode decomposition to separate deterministic and stochastic velocities from a single Lagrangian drifter. Journal of Geophysical Research: Oceans, 123, 1708–1721. https://doi. org/10.1002/2017JC013500
Distribution Statement
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.