Figure 2
From: Enduring Lagrangian coherence of a Loop Current ring assessed using independent observations
In grey, contour levels of the altimetric sea surface height (SSH) field in the Gulf of Mexico (GoM) on selected days. Overlaid in blue are snapshots of the passive evolution, according to the altimetry-derived flow, of tracers initially on 29 May 2013 along the outermost of the closed SHH streamlines filling a mesoscale region of nearly 100-km radius in the center of the GoM, which has been identified as a Loop Current ring (LCR) and named Kraken. These closed instantaneous SSH streamlines are the Eulerian footprints of a coherent Lagrangian LCR, which nearly steadily translates westward across the GoM. The solid red curve is the boundary for the longest-lived and largest coherent Lagrangian LCR core. The dashed red curve is a material loop that provides repeated, short-term shielding to this core. Figures constructed using MATLAB R2017b (http://www.mathworks.com/).
