Abstract's details

A New Global Mesoscale Eddy Trajectory Atlas Derived from Altimetry : Presentation and Future Evolutions

Cori Pegliasco (CLS, France)

CoAuthors

Antoine Delepoulle (CLS, France); Clément Busché (CLS, France); Rosemary Morrow (LEGOS, France); Yannice Faugère (CLS, France); Gerald Dibarboure (CNES, France)

Event: 2022 Ocean Surface Topography Science Team Meeting

Session: Science III: Mesoscale and sub-mesoscale oceanography

Presentation type: Type Oral

Mesoscale eddies are ubiquitous in the ocean. When they rotate faster than they travel, they can trap water into their cores and transport it along their paths, redistributing heat, salt, chemical and biological components from their generation to their dissipation areas.
The new versions of the global Mesoscale Eddy Trajectory Atlas (META) 3.2 Delayed Time all-satellites and two-satellites are produced by SSALTO/DUACS and distributed by AVISO+ (https://aviso.altimetry.fr) with support from CNES. Significant changes from the historical 2.0 version previously distributed and regularly updated were made to provide an improved representation of the mesoscale eddies, illustrated here.
The META3.2 detection scheme is based on the Py-Eddy-Tracker algorithm (Mason et al., 2014, https://github.com/AntSimi/py-eddy-tracker), applied on Absolute Dynamic Topography (ADT, DUACS DT2021 reprocessing) maps filtered to remove large-scale patterns. ADT-detection better represents quasi-stationary and recurrent structures than sea level anomaly based detection. The amplitude threshold is reduced to 0.4 cm, increasing the number of small eddies, in particular during the growing and decay phases of the trajectories, or close to coasts and islands. Only one local extremum is tolerated within an eddy contour, with a better agreement with ocean color data tan the multiple-extrema structures authorized before. The tracking scheme is based on the contours’ overlap (following Pegliasco et al., 2015) instead of the research of eddy candidates in a restricted area, reducing the wrong temporal associations. To provide maximal information, META3.1exp products make available the structures detected only one day, the trajectories lasting less than 10 days and the trajectories lasting at least 10 days in different files. The products also include new information such as the mesoscale eddy shapes with the eddy edges and the contour associated with the maximum averaged-speed, and the eddy speed profiles from the center to the edge. Thus, META3.2 products allow easier collocation of data for transdisciplinary research. A future evolution of the product is to include the eddies’ interactions (merging and splitting events) with a network representation (META-Networks). This evolution will be discussed with the users to best meet their needs.

 

Oral presentation show times:

Room Start Date End Date
Sala Grande Wed, Nov 02 2022,16:48 Wed, Nov 02 2022,16:59
Cori Pegliasco
CLS
France
cpegliasco@groupcls.com