Using kinetic energy measurements from altimetry to detect shifts in the positions of fronts in the Southern Ocean
Event: 2017 Ocean Surface Topography Science Team Meeting
Session: Science III: Mesoscale and sub-mesoscale oceanography
Presentation type: Type Poster
A novel analysis is performed utilizing cross-track kinetic energy (CKE) computed from sea surface height anomalies derived from along-track satellite altimetry. The mid-point of enhanced kinetic energy averaged over three-year periods from 1993 to 2015 is determined across the Southern Ocean and examined to detect shifts in frontal positions, based on previous observations that kinetic energy is largest along fronts and jets in the Antarctic Circumpolar Current system. It is demonstrated that although the CKE does not represent the full eddy kinetic energy (computed from crossovers), the shape of the enhanced regions along groundtracks is the same, and CKE has a much finer spatial sampling of 6.9 km. Results indicate no significant shift in the front positions across the Southern Ocean, on average, although there are some localized, large movements. This is consistent with other studies utilizing sea surface temperature gradients and the latitude of mean transport, but inconsistent with studies utilizing the movement of contours of dynamic topography.