On modulation instability in a system of jets, waves and eddies off California
MetadataShow full item record
SSH altimetry observations for 1992 to 2009 off Central and Southern California are used to show that observed quasi-zonal jets were likely driven by near-resonance interactions between different scales of the flow. Quartet (modulational) instability dominated and caused non-local transfer of energy from waves and eddies to bi-annual oscillations and quasi-zonal jets. The total number of quartets induced off California was approximately 10 times larger than the number of existing triads, and quartet amplitudes in general were larger than triad amplitudes. The spectral centroid regularly shifted into the domain of low-order modes. Local “negative” viscosity probably did not generate a classical inverse cascade because the spectrum of SSHs did not demonstrate power behavior. Two types of quartets were identified: (a) quasi-zonal jets, annual and semi-annual Rossby waves and eddies, and (b) bi-annual oscillations, semiannual Rossby waves and eddies. For a case with bottom friction, quartet instability required the existence of a certain level of dissipativity in the flow.
The article of record as published may be found at http://dx.doi.org/10.5194/npgd-1-97-2014Discussion Paper
Showing items related by title, author, creator and subject.
Semtner, Albert J. Jr.; Chervin, Robert M. (American Geophysical Union, 1992-04-15);A concerted effort has been made to simulate the global ocean circulation with resolved eddies, using a highly optimized model on the best available supercomputer. An earlier 20-year spin-up has been extended for 12.5 ...
Ivanov, L.M.; Collins, C.A.; Margolina, T.M. (2014);Sea surface height (SSH) altimetry observations for 1992 to 2009 off California are used to show that observed quasi-zonal jets were likely driven by near-resonance interactions between different scales of the flow. ...
Collins, C. A.; Pennington, J. T.; Castro, C. G.; Rago, T. A.; Chavez, F. P. (Elsevier, 2003);Repeated hydrobiological surveys over the period 1988-2002 perpendicular to the central California coast indicate strong coupling between physical circulation and biological production. An equatorward-flowing jet about ...