Increase of eddy kinetic energy towards the equator

• Applicant: Dr. Jürgen Theiss
• Subject Area: Atmospheric Science
• Term: from 2001 to 2003
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5330486

TOPEX/Poseidon satellite measurements of the global sea surface have revealed, for the first time, the global distribution of eddy kinetic energy in the oceans (e.g. Stammer 1997). The striking feature of this distribution is an increase of eddy kinetic energy towards the equator. This phenomenon, unobserved until 1997, was theoretically predicted 15 years earlier by Salmon (1982). Surprisingly, this prediction attracted little attention, perhaps because of the unavailability of supporting observational evidence, or perhaps because Salmon´s theory is based on simplifying assumptions whose validity ist not fully evident. It is therfore timely to revisit Salmon´s theory and to consider possible extensions or alternatives to the theory, in order to obtain more quantitative predictions and closer comparisons with observations. Like all turbulence theories Salmons´s theory is based on a statistical description of turbulent flow. Furthermore, its formulation and assumptions allow only qualitative predictions of tendencies of the flow, for a certain parameter regime that might not be realistic. Despite its limitations, it leads nevertheless to the prediction already mentioned, of an increase in eddy kinetic energy towards to the equator. Thus, Salmon´s theory and the TOPEX/Poseidon observations not only motivate but demand an understanding of the physical mechanisms underlying the energy increase. Obtaining that understanding, through a sufficiently good theory

• DFG Programme: Research Fellowships
• International Connection: USA