Results 261 to 270 of about 7,530,486 (302)

Empirical Orthogonal Functions and Normal Modes

Journal of the Atmospheric Sciences, 1984
An attempt to provide physical insight into the empirical orthogonal function (EOF) representation of data fields by the study of fields generated by linear stochastic models is presented in this paper. In a large class of these models, the EOFs at individual Fourier frequencies coincide with the orthogonal mechanical modes of the system - provided ...
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Examples of Extended Empirical Orthogonal Function Analyses

Monthly Weather Review, 1982
Abstract An extended empirical orthogonal function analysis technique is described which expands a data set in terms of functions which are the “best” representation of that data set for a sequence of time points. The method takes advantage of the fact that geophysical fields are often significantly correlated in both space and time.
Bryan C. Weare, John S. Nasstrom
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Linear embedding of attractors by bi-orthogonal decomposition and empirical orthogonal functions

Il Nuovo Cimento B Series 11, 1995
Some characteristics of the bi-orthogonal-decomposition method are rigorously described and compared to those of the empirical-orthogonal-function analysis (EOFA). We suggest the extension of some properties of such method to EOFA to obtain a useful tool in detecting bifurcations for time series.
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Empirical Normal Modes versus Empirical Orthogonal Functions for Statistical Prediction

Journal of the Atmospheric Sciences, 1996
Abstract The theory of empirical normal modes (ENMs) for a shallow water fluid is developed. ENMs are basis functions that both have the statistical properties of empirical orthogonal functions (EOFs) and the dynamical properties of normal modes. In fact, ENMs are obtained in a similar manner as EOFs but with the use of a quadratic form instead of the ...
Gilbert Brunet, Robert Vautard
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Detection of oceanographic fronts using empirical orthogonal functions

OCEANS 2017 - Aberdeen, 2017
Oceanographic fronts are boundaries between water masses with differences in hydrography. Often the presence of fronts coincide with oceanographic currents. The detection of fronts has traditionally been carried out by looking for sudden horizontal changes in the sea surface temperature or salinity. Applications involving temperature or salinity alone,
Karl Thomas Hjelmervik, Karina Hjelmervik, Lloyd Andreassen   +2 more
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A Dynamical Empirical Orthogonal Function Analysis of the Intraseasonal Disturbances

Journal of the Atmospheric Sciences, 1993
Abstract This study investigates the structural properties of the intraseasonal disturbances in the 500-mb flow during a specific winter season (1982/83) and assesses the relevance of normal-mode barotropic instability to the observed intraseasonal disturbances. The leading complex empirical orthogonal function (CEOF1) accounts for 56% of the variance,
Joseph J-C. Chang, Mankin Mak
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Application of the expansion into empirical orthogonal functions to ionospheric characteristics

Advances in Space Research, 1990
Abstract Representation of empirical models of ionospheric characteristics in terms of empirical orthogonal functions (EOF), as proposed by DVINSKIKH /1/, has been applied to the critical frequencies, foF2, and the peak heights, hmF2, of the F2 layer in the International Reference Ionosphere (IRI) and in ionospheric prediction models.
W. Singer, J. Taubenheim
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Empirical Orthogonal Function Analysis of Hawaiian Rainfall

Journal of Applied Meteorology, 1982
Abstract Empirical orthogonal function analysis was applied to monthly mean rainfall data at 63 stations in Hawaii encompassing a 37-year period. Major rainfall patterns in order to importance (E1–E3) proved to be trade wind, southwest wind and convective rainfall on an annual basis; trade wind, southwest wind and frontal rainfall during winter, spring
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Reconstructing a Band-limited function Using Empirical Orthogonal Functions

2006 IEEE Instrumentation and Measurement Technology Conference Proceedings, 2006
A reconstruction procedure for a band-limited function from its samples taken in a finite segment is systematically developed under an a priori assumption of bandwidth. The rationale of the proposed scheme is to expand the known signal segment based on a band-limited basis function set and then to generate a set of empirical orthogonal functions (EOF's)
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A spectral barotropic model in horizontal empirical orthogonal functions

Quarterly Journal of the Royal Meteorological Society, 1975
AbstractA limited area barotropic vorticity equation model is integrated using a representation in terms of 57 horizontal empirical orthogonal functions. No boundary conditions are applied; the inflow and outflow of weather systems are absolutely free. The length of the time step in a normal centred scheme can be as much as 10 hours.
JUHANI RINNE, VESA KARHILA
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