Has Lydia found a new eddy?

There has been lots of excitement recently about Lydia, an approximately 2,000 lbs. white shark, and her recent eastward movement offshore towards a region populated with large Gulf Stream eddies. Until yesterday, Lydia was moving mostly due east. But now, she has taken a sudden turn north. To investigate if her change in course could be cued by the presence of a particular eddy, I overlaid her track on a map of near-real time SSH (data from http://eddy.colorado.edu/ccar/ssh/nrt_global_grid_viewer).

Sure enough, her turn to the north puts her in the region of a large anticyclonic (clockwise rotation) eddy or meander, characterized by warm water low in chlorophyll (algae).  We’ll have to see where she goes next to find out of she decides to stay in this eddy, or keeps moving north-northeast.

Lydia's track (starting Nov 4th and ending Nov 24th, 2014) overlaid on a map of sea level anomaly (often referred to as SSH, sea level height).

Lydia’s track (starting Nov 4th and ending Nov 24th, 2014) overlaid on a map of sea level anomaly (often referred to as SSH, sea surface height).  Track data courtesy of ocearch.org and SSH data of the Colorado Center for Astrodynamics Research (CCAR).

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