Assessing Transport in the Ocean and Atmosphere: Computational Tools for Predictability and Experimental Design

Abstract

This effort addressed applications of dynamical systems to aperiodic, two-dimensional velocity fields, and improvements in the numerical tools available to perform such analysis. Invariant manifold techniques were used to estimate the extent of mixing in a barotropic meandering jet (Gulf Stream), showing that transport is on the same order as cross-jet transport due to ring detachment. Manifold calculations verified theoretical predictions of separatrix splitting in a viscous perturbation of the barotropic pv equation. In a simulation of an island recirculation, lobe analysis shed light on the importance of chaotic transport relative to Ekman transport. A pv budget was calculated for the gyre using a Lagrangian definition of the recirculation. The results imply that the budget for a time-averaged fixed boundary may typically overestimate the importance of chaotic advection in the overall vorticity budget. The vftool software package went through a major rewrite, including a better ODE solver, improved command-line interface and model input, a greatly expanded and improved Matlab toolbox, and compatibility with several variants of Unix.

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Document Details

Document Type
Technical Report
Publication Date
Jul 06, 2004
Accession Number
ADA424272

Entities

People

  • Patrick D. Miller

Organizations

  • Stevens Institute of Technology

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Advection
  • Boundaries
  • Boundary Layer
  • Computational Fluid Dynamics
  • Computational Science
  • Data Analysis
  • Differential Equations
  • Equations
  • Experimental Design
  • Gulf Stream
  • Mixing
  • Operating Systems
  • Simulations
  • Stratified Fluids
  • Time Dependence
  • Turbulent Mixing
  • Two Dimensional

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Computational Modeling and Simulation
  • Fluid Mechanics and Fluid Dynamics.