P1.21
Anisotropy of the kinetic energy cascade measured with altimeter data for the World Ocean
Robert Bruce Scott, Jackson School of Geosciences, University of Texas, Austin, TX; and B. Qiu
The dynamical origin of the apparently ubiquitous jets seen in observations and realistic model simulations of the World Ocean remains unclear. We address the possibility of a nonlinear origin by directly measuring the turbulent kinetic energy cascade. Six years of sea-surface height observations from multiple satellites reveal a ubiquitous preference for current anomalies stretched in the zonal direction. The two-dimensional nonlinear spectral transfer revealed that forcing preferentially drives meridionally elongated flow, the signature of potential energy release via baroclinic instability. A nonlinear cascade redistributes energy preferentially to larger scales, and toward zonally elongated flow, direct observational evidence of the beta-effect on the inverse cascade anisotropy. Still unexplained, the cascade was found to be less effective at higher latitudes.
Poster Session 1, Ocean Dynamics
Monday, 25 June 2007, 5:00 PM-6:30 PM, Ballroom North
Previous paper