Clustering of Loop Current patterns based on the satellite-observed sea surface height and self-organizing map

Abstract

The self-organizing map is used to investigate variations of the Loop Current (LC) in the Gulf of Mexico from 1992 to 2013 based on satellite-observed sea surface height data. It is found that LC variations can be characterized by three spatial patterns: normal, extension and retraction. The corresponding temporal variations confirm that LC eddy shedding generally occurs during the transition from the extension to retraction patterns. On the weekly time scale, the wind stress curl (WSC) in the Caribbean Sea has a major influence on LC eddy shedding. The increase of Caribbean WSC from June to November favours more frequent LC eddy shedding during that period. On the interannual time scale, there is also a potential linkage between the frequency of LC eddy shedding and El Niño activities.

Acknowledgements

The authors would like to acknowledge the Helsinki University of Technology, Finland for providing the SOM Toolbox and Dr. Y. Liu of University of South Florida for useful guidance on the SOM application in oceanography. Constructive comments provided by two anonymous reviewers and J. Warrillow’s editorial assistance are also appreciated.

Additional information

Funding

Research support provided by Gulf of Mexico Research Initiative/GISR [grant number 02-S130202]; NOAA [grant number NA11NOS0120033]; NASA [grant number NNX12AP84G], [grant number NNX13AD80G] is much appreciated.