What makes the Deep Western Boundary Current "leak"?

Aviv Solodoch1, James C McWilliams2, Andrew Stewart3, Jonathan Gula4 and Lionel Renault3, (1)University of California Los Angeles, Los Angeles, CA, United States, (2)UCLA, Los Angeles, CA, United States, (3)University of California Los Angeles, Atmospheric and Oceanic Sciences, Los Angeles, CA, United States, (4)Laboratoire de Physique des Océans, Brest, France