IFIBA   22255
INSTITUTO DE FISICA DE BUENOS AIRES
Unidad Ejecutora - UE
artículos
Título:
Inverse cascades in rotating stratified turbulence: Fast growth of large scales
Autor/es:
R. MARINO; P. D. MININNI; D. ROSENBERG; A. POUQUET
Revista:
EUROPHYSICS LETTERS
Editorial:
EPL ASSOCIATION
Referencias:
Lugar: Bologna; Año: 2013 vol. 102 p. 440061 - 440066
ISSN:
0295-5075
Resumen:
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.