Klymak, Jody M.Shearman, R. KippGula, JonathanLee, Craig M.D'Asaro, Eric A.Thomas, Leif N.McWilliams, James C.2020-11-122020-11-1220162016Klymak, J. M., Shearman, R. K., Gula, J., Lee, C. M., D;Asaro, E. A., Thomas, L. N., & McWilliams, J. C. (2016). Submesoscale streamers exchange water on the north wall of the Gulf Stream. Geophysical Research Letters, 43(3), 1226-1233. https://doi.org/10.1002/2015GL067152.https://doi.org/10.1002/2015GL067152http://hdl.handle.net/1828/12347The Gulf Stream is a major conduit of warm surface water from the tropics to the subpolar North Atlantic. Here we observe and simulate a submesoscale (<20 km) mechanism by which the Gulf Stream exchanges water with subpolar water to the north. Along isopycnals, the front has a sharp compensated temperature‐salinity contrast, with distinct mixed water between the two water masses 2 and 4 km wide. This mixed water does not increase downstream despite substantial energy available for mixing. A series of streamers detrain this water at the crest of meanders. Subpolar water replaces the mixed water and resharpens the front. The water mass exchange accounts for a northward flux of salt of 0.5–2.5 psu m2 s−1, (large‐scale diffusivity O (100 m2 s−1)). This is similar to bulk‐scale flux estimates of 1.2 psu m2 s−1 and supplies fresher water to the Gulf Stream required for the production of 18° subtropical mode water.enocean mixingGulf Streamsubmesoscale mixingeddiesArticleSchool of Earth and Ocean Sciences