Gravity Wave Instability Dynamics at High Reynolds Numbers. Part II: Turbulence Evolution, Structure, and Anisotropy

• Published in: Journal of the atmospheric sciences Vol. 66; no. 5; pp. 1149 - 1171
• Main Authors: FRITTS, David C, LING WANG, WERNE, Joe, LUND, Tom, WAN, Kam
• Format: Journal Article
• Language: English
• Published: Boston, MA American Meteorological Society 01.05.2009
• Subjects: Amplitudes; Anisotropy; Atmospheric boundary layer; Breaking; Buoyancy; Convective instability; Dynamic stability; Earth, ocean, space; Energy dissipation; Evolution; Exact sciences and technology; External geophysics; Fluid dynamics; Fluid flow; General circulation models; Gravity waves; High performance computing; High Reynolds number; Instability; Intermittency; Laboratories; Measurement techniques; Meteorology; Numerical analysis; Physics of the high neutral atmosphere; Reynolds number; Shear; Simulation; Turbulence; Turbulent flow; Vortices; Wave breaking; Wave period; Large Reynolds number; Gravity wave; anisotropy; breaking waves; turbulent flow; Turbulence energy; Convective instability; turbulence; buoyancy; Wave breaking; Turbulence structure; Intermittency
• ISSN: 0022-4928; 1520-0469
• DOI: 10.1175/2008jas2727.1

This paper examines the character, intermittency, and anisotropy of turbulence accompanying wave instability, breaking, and turbulence evolution and decay for gravity waves (GW) having a high intrinsic frequency, amplitudes above and below nominal convective instability, and a high Reynolds number. Wave breaking at both amplitudes leads to an extended inertial range of turbulence, with turbulence energies that maximize within ~1 wave period of the onset of breaking. Turbulence sources include both shear and buoyancy, with shear being the major contributor. Turbulence displays considerable intermittency both within and across the phase of the breaking gravity wave and exhibits clear anisotropy throughout the evolution. Turbulence anisotropy is found at all spatial scales and all times but is most pronounced in the most statically stable phase of the GW and at late times as the turbulent flow restratifies. [PUBLICATION ABSTRACT]