Analysis of Sparse and Noisy Ocean Current Data Using Flow Decomposition. Part 1: Theory

A new approach is developed to reconstruct a three-dimensional incompressible flow from noisy data in an open domain using a two-scalar (toroidal and poloidal) spectral representation. The results are presented in two parts: Theory (first part) and Application (second part). In Part I, this approach...

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Bibliographic Details
Main Authors: Chu, Peter C., Ivanov, Leonid M., Korzhova, Tatiana P., Margolina, Tatiana M., Melnichenko, Oleg V.
Other Authors: NAVAL POSTGRADUATE SCHOOL MONTEREY CA NAVAL OCEAN ANALYSIS AND PREDICTION LAB
Format: Text
Language:English
Published: 2003
Subjects:
Physical and Dynamic Oceanography
Hydrology
Limnology and Potamology
Computer Programming and Software
Fluid Mechanics
*VELOCITY
*OCEAN CURRENTS
*EULER EQUATIONS
*THREE DIMENSIONAL FLOW
*LAGRANGIAN FUNCTIONS
*INCOMPRESSIBLE FLOW
KINEMATICS
GRAPHS
SIGNAL TO NOISE RATIO
WHITE NOISE
OCEANOGRAPHIC DATA
LEAST SQUARES METHOD
BLACK SEA
POISSON EQUATION
CHANNELS(WATERWAYS)
SCALAR FUNCTIONS
SHALLOW WATER
REGRESSION ANALYSIS
EIGENVECTORS
OBSERVATION
REPRINTS
OPTIMIZATION
*VELOCITY FIELDS
*RECONSTRUCTION
*FLOW DECOMPOSITION
OPEN BOUNDARY CONDITIONS
MIXED BOUNDARY CONDITIONS
BASIS FUNCTIONS
NOISY DATA
SPARSE DATA
HORIZONTAL VELOCITY
VERTICAL VELOCITY
DIRICHLET BOUNDARY CONDITION
NEUMANN BOUNDARY CONDITION
LAPLACIAN OPERATOR
COST FUNCTIONS
SOUTHERN OCEAN
REGULARIZATION TECHNIQUE
ROOT-MEAN-SQUARE ERROR
BUOY DATA
COLOR NOISE
Southern Ocean
Online Access:http://www.dtic.mil/docs/citations/ADA479483
http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA479483
Description
Summary:A new approach is developed to reconstruct a three-dimensional incompressible flow from noisy data in an open domain using a two-scalar (toroidal and poloidal) spectral representation. The results are presented in two parts: Theory (first part) and Application (second part). In Part I, this approach includes the following: (a) a boundary extension method to determine normal and tangential velocities at an open boundary, (b) establishment of homogeneous open boundary conditions for the two potentials with a spatially varying coefficient kappa, (c) spectral expansion of kappa, (d) calculation of basis functions for each of the scalar potentials, and (e) determination of coefficients in the spectral decomposition of both velocity and kappa using linear or nonlinear regressions. The basis functions are the eigenfunctions of the Laplacian operator with homogeneous mixed boundary conditions and they depend upon the spatially varying parameter kappa at the open boundary. A cost function used for poor data statistics is introduced to determine the optimal number of basis functions. An optimization scheme with iteration and regularization is proposed to obtain unique and stable solutions. In Part II, the capability of the method is demonstrated through the reconstruction of a 2D wind-driven circulation in a rotating channel, a baroclinic circulation in the eastern Black Sea, and a large-scale surface circulation in the Southern Ocean. Pub. in the Journal of Atmospheric and Oceanic Technology, v20, p478-491, Apr 2003. Prepared in cooperation with the Marine Hydrophysical Institute and Center for Ecological Modeling and Recreation Geography, National Ukrainian Academy of Sciences, Sevastopol, Crimea, Ukraine.

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