Emergence of helicity in rotating stratified turbulence

AMS Citation:
Marino, R., P. D. Mininni, D. Rosenberg, and A. Pouquet, 2013: Emergence of helicity in rotating stratified turbulence. Physical Review E, 87, 9 pp, doi:10.1103/PhysRevE.87.033016.
Date:2013-03-01
Resource Type:article
Title:Emergence of helicity in rotating stratified turbulence
Abstract: We perform numerical simulations of decaying rotating stratified turbulence and show, in the Boussinesq framework, that helicity (velocity-vorticity correlation), as observed in supercell storms and hurricanes, is spontaneously created due to an interplay between buoyancy and rotation common to large-scale atmospheric and oceanic flows. Helicity emerges from the joint action of eddies and of inertia-gravity waves (with inertia and gravity with respective associated frequencies f and N), and it occurs when the waves are sufficiently strong. For N/f<3 the amount of helicity produced is correctly predicted by a quasilinear balance equation. Outside this regime, and up to the highest Reynolds number obtained in this study, namely Re⋲10 000, helicity production is found to be persistent for N/f as large as ⋲17, and for ReFr² and ReRo², respectively, as large as ⋲100 and ⋲24 000.
Peer Review:Refereed
Copyright Information:Copyright 2013 American Physical Society.
OpenSky citable URL: ark:/85065/d7vd7088
Publisher's Version: 10.1103/PhysRevE.87.033016
Author(s):
  • Raffaele Marino - NCAR/UCAR
  • Pablo Mininni - NCAR/UCAR
  • Duane Rosenberg
  • Annick Pouquet - NCAR/UCAR
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