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Subscriber Access to Full Article (Nonsubscribers may purchase for $9.00, Includes print PDF, file size: 1077306 bytes)
GEOPHYSICAL RESEARCH LETTERS,
VOL. 34,
L22801,
doi:10.1029/2007GL031779,
2007
Recovery of atmospheric flow statistics in a general circulation model without nonlinear eddy-eddy interactions
Paul A. O'Gorman
California Institute of Technology, Pasadena, California, USA
Tapio Schneider
California Institute of Technology, Pasadena, California, USA
Abstract
The closure problem of turbulence arises because nonlinear interactions among turbulent fluctuations (eddies) lead to an infinite
hierarchy of moment equations for flow statistics. Here we demonstrate with an idealized general circulation model (GCM) that
many atmospheric flow statistics can already be recovered if the hierarchy of moment equations is truncated at second order,
corresponding to the elimination of nonlinear eddy-eddy interactions. Some, but not all, features of the general circulation
remain the same. The atmospheric eddy kinetic energy spectrum retains a −3 power-law range even though this is usually explained
in terms of an enstrophy cascade mediated by nonlinear eddy-eddy interactions. Our results suggest that it may be possible
to construct fast general circulation models that solve for atmospheric flow statistics directly rather than via simulation
of individual eddies and their interactions.
Received 22
August
2007;
accepted 12
October
2007;
published 16
November
2007.
Keywords: turbulence;
general circulation model;
energy spectrum.
Index Terms: 3379 Atmospheric Processes: Turbulence (4490); 3319 Atmospheric Processes: General circulation (1223); 3367 Atmospheric Processes: Theoretical modeling.
Subscriber Access to Full Article (Nonsubscribers may purchase for $9.00, Includes print PDF, file size: 1077306 bytes)
Citation: O'Gorman, P. A., and T. Schneider
(2007),
Recovery of atmospheric flow statistics in a general circulation model without nonlinear eddy-eddy interactions,
Geophys. Res. Lett.,
34,
L22801,
doi:10.1029/2007GL031779.
Copyright 2007 by the American Geophysical Union.
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