The Interpretation of Space-Time Spectral Quantities

Abstract

The frequency averaging implicit in the calculation of space-time spectra complicates the interpretation of eastward and westward variance and covariance components. One-sided (in frequency) space-time spectral definitions are proposed in an effort to avoid some of the ambiguities of such two-sided spectra, and better define the role of standing and zonally propagating fluctuations. Problems are discussed which affect both one- and two-sided spectra, especially for the mid-latitude planetary scales.