HARMONIC REPRESENTATION APPLIED TO LARGE SCALE ATMOSPHERIC WAVES,
Abstract
Spectral analysis (primarily in terms of spherical harmonics) is applied to the atmospheric dynamical equations in general, to truncated barotropic systems in particular and, in addition, to the global geopotential height field of the 500 mb surface for September 1957. The complete set of equations governing adiabatic frictionless flow transform into the spectral domain, and are energetically consistent under practically any truncation procedure. Analysis of truncated barotropic systems leads to a reinterpretation of barotropic instability in terms of the frequency of momentum transport. There is no evidence that the fluctuations of spherical harmonic waves at 500 mb are global in character, but the lack of data in the southern hemisphere limits the validity of this conclusion. Hemispheric analysis of the geopotential height field at 500 mb for the northern hemisphere indicates that the planetary waves are composed of a quasi-stationary component and a rapidly retrogressive component whose phase speeds are a large fraction of the theoretical Rossby-Haurwitz phase speeds. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1966
- Accession Number
- AD0642154
Entities
People
- Philip Merilees
Organizations
- McGill University