Nonlinear Cascades of Surface Oceanic Geostrophic Kinetic Energy in the Frequency Domain*

• DOI: 10.1175/jpo-d-11-0151.1
• Publication Date: 2012-04-17T17:05:38Z
• Authors: Brian K. Arbic; Robert B. Scott; Glenn R. Flierl; Andrew J. Morten; James G. Richman; Jay F. Shriver
• Keywords: Energy cascade; Smoothing; Wavenumber; Ocean dynamics

Abstract Motivated by the ubiquity of time series in oceanic data, relative lack studies geostrophic turbulence frequency domain, and interest quantifying contributions intrinsic nonlinearities to spectra, this paper examines spectra spectral fluxes surface flows domain. Spectra are computed from idealized two-layer quasigeostrophic (QG) models realistic ocean general circulation models, as well gridded satellite altimeter data. The variance streamfunction (akin sea height) velocity qualitatively similar all these, with substantial extending out low frequencies. flux Π(ω) kinetic energy ω domain for QG model documents a tendency nonlinearity drive toward longer periods, like manner inverse cascade larger length scales documented calculations Π(k) wavenumber k Computations also display an “inverse temporal cascade.” In some regions dominated cascade, whereas others exhibit forward cascade. However, performed temporally and/or spatially filtered output demonstrate that values highly susceptible smoothing inherent construction products. Therefore, at present it is difficult say whether cascades seen data represent physics missing studied here or merely sampling artifacts.