beginner issue

[Kris-wu-glut]

hi,i justI just started to study the ocean eddies,I want to know what the two circles of the eddies represent respectively.

[AntSimi]

dashed line => effective contour
solid line => speed contour
For more information look at Figure 1 at the reference paper of py-eddy-tracker https://doi.org/10.1175/JTECH-D-14-00019.1

[Kris-wu-glut]

thanks, it helped me a lot.