Inetrio-gravity wave parameter estimation from cross-spectral analysis

We outline a method for extracting inertio-gravity wave parameters using the autospectra and cross spectra of the horizontal perturbation winds. In essence, we define a statistical hodograph for each spectral bin, thus combining the advantages of the rotary spectrum and hodograph methods. Furthermore, we include the effects of the background vertical shear in the parameter estimation equations, • step that had often been omitted in the past. Applying this technique to a long-period data set taken with the Arecibo 430-MHz radar, we explore its usefulness as well as its limitations. Our analysis of this data set also supports the interpretation of horizontal wind-perturbation rotation in the lower stratosphere over Arecibo as inertio-gravity waves rather than mountain waves imbedded within a background vertical shear.