POD analysis of baroclinic wave flows in the thermally-driven, rotating annulus experiment

The Proper Orthogonal Decomposition (POD) is a procedure to compute an orth ogonal basis from a time series of spatial fields. This basis is optimal am ong all linear decompositions, in the sense that for a given number of mode s, the projection of the original signal onto the subspace will contain the most variance on average. This algorithm is applied to streamfunction fiel ds derived from measurements of the flow in the thermally forced rotating a nnulus experiment. Results of this analysis are presented, and a method to derive low-dimensional models of the flow by projecting the equations of mo tion onto these empirical eigenfunctions is discussed. (C) 1999 Elsevier Sc ience Ltd. All rights reserved.