Testing theories of atmospheric gravity wave saturation and dissipation

Abstract

Numerous mechanisms have been proposed to account for the dissipation and saturation of gravity waves in the atmosphere. We review the leading wave dissipation paradigms and identify the experimental data required to test definitively the fundamental physics upon which these theories are based. We also examine the separability of the joint vertical wave number (m) and temporal frequency (ω) spectrum and the separability of the unambiguous two-dimensional horizontal wave number spectrum. Definitive tests of the Linear Instability (Dewan and Good, 1986), Saturated-Cascade (Dewan, 1994), and Diffusive Filtering Theories (Gardner, 1994) and separability of the (m, ω) spectrum are within the observational capabilities of modern remote sensing instruments. The Diffusive Damping (Weinstock, 1990) and Doppler Spreading Theories (Hines, 1991) are untestable in their present forms. Separability of the two-dimensional horizontal wave number spectrum is difficult to test using current technology, although analysis of airglow images may provide some insight.