Analysis of kinetic energy and structure functions from along-track and crossover altimeter data
Event: 2020 Ocean Surface Topography Science Team Meeting (virtual)
Session: Salient results from the 2017-2020 OSTST PIs
Presentation type: Type Forum only
We present salient results of our funded Ocean Surface Topography Science Team investigation on understanding how kinetic energy in the Southern Ocean is changing. We have developed a method to track frontal movement based on envelopes of enhanced kinetic energy and find no significant trends since 1993. We have also conducted a sampling experiment with a high-resolution model to understand potential errors in using eddy kinetic energy (EKE) from altimeter crossovers. Our results suggest that if EKE is averaged over at least 30° longitude and 10° latitude sectors, crossovers can accurately track interannual fluctuations in EKE. Using crossovers, we find that there has been no significant trends in EKE over the entire Southern Ocean, just limited regions downstream from topography where EKE has increased, primarily south of Australia and New Zealand. Finally, we have developed a novel theory of turbulence to explain short-wavelength spectra. We have tested the theory against high-resolution current data from acoustic doppler current profilers (ADCPs) and find good agreement. This suggest we may be able to use this theory to generate more realistic pseudo-SSH data that better represents sub-mesoscale turbulence.