Inverse cascades in rotating stratified turbulence: Fast growth of large scales

• Autores: Marino, R.; Mininni, Pablo Daniel; Rosenberg, D; Pouquet, A.
• Año de publicación: 2013
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Helicity; Rotating Flows; Stratified Flows; Geostrophy
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

We examine the inverse cascade of kinetic energy to large scales in rotating stratified turbulence as occurs in the oceans and in the atmosphere, while varying the relative frequency of gravity to inertial waves, N/f. Using direct numerical simulations with grid resolutions up to 10243 points, we find that the transfer of energy from three-dimensional to two-dimensional modes is most efficient in the range 1/2 N/f 2, in which resonances disappear. In this range, the cascade is faster than in the purely rotating case, and thus the interplay between rotation and stratification helps creating large-scale structures. The ensuing inverse cascade follows a −5/3 spectral law with an approximately constant flux. This inverse cascade becomes negligible when stratification is dominant.
Fil: Marino, R.. National Center for Atmospheric Research; Estados Unidos de América;
Fil: Mininni, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; Argentina. National Center for Atmospheric Research; Estados Unidos de América;
Fil: Rosenberg, D. Oak Ridge National Laboratory; Estados Unidos
Fil: Pouquet, A.. National Center for Atmospheric Research; Estados Unidos de América;