117 research outputs found
Large-scale energy spectra in surface quasi-geostrophic turbulence
The large-scale energy spectrum in two-dimensional turbulence governed by the
surface quasi-geostrophic (SQG) equation
is studied. The nonlinear transfer of this system conserves the two quadratic
quantities and
(kinetic energy), where denotes
a spatial average. The energy density is bounded and its spectrum
is shallower than in the inverse-transfer range. For
bounded turbulence, in the low-wavenumber region can be bounded by
where is a constant independent of but dependent on the domain
size. Results from numerical simulations confirming the theoretical predictions
are presented.Comment: 11 pages, 4 figures, to appear in JF
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