Mesoscale Eddies in Altimeter Observations of SSH

Dudley B. Chelton and Michael G. Schlax

The trajectories of mesoscale eddies were first released in February 2011 for the 16-year time period October 1992 through December 2008. A 2nd release in November 2011 extended this eddy dataset through January 2011 based on the SSH fields in Version 3 of the AVISO Reference Series. This new 3rd release extends the eddy dataset through April 2012, which marked the end of availability of a European altimeter with 35-day repeat orbit for the AVISO Reference Series. The eddy identification and tracking procedure was modified slightly to reduce the number of poorly shaped eddies, most of which had short lifetimes. As in the two previous eddy datasets, this new 19.5-year version retains only those eddies with lifetimes of 4 weeks or longer and the trajectories are available at 7-day time steps. There is a total of 215,184 such eddies.

A detailed analysis of the first version of the eddy dataset can be found in Chelton et al. (2011). The main text of this paper summarizes the characteristics of the eddies with lifetimes of 16 weeks and longer. Appendices A.1 - A.3 assess the filtering properties of the objective analysis procedure used by AVISO to construct the SSH fields from which the eddies were identified and tracked. Appendices B.1 - B.5 describe the details of the eddy identification and tracking procedure and Appendix C assesses the adequacy of the procedure.

The figures in Chelton et al. (2011) made from this new 19.5-year version of the eddy dataset can be downloaded HERE as a PDF file.

Chelton, D. B., M. G. Schlax, and R. M Samelson, 2011: Global observations of nonlinear mesoscale eddies. Prog. Oceanogr., 91, 167-216.