During the summer, the shelf/slope water from the New York Bight is thermohaline with strong temperature and salinity gradients occuring on isopycnals connecting shelf and slope water. The dominant lateral exchange is via slope water intrusions above and below the cold pool, a remnant of winter-mixed shelf water. These intrusions create environments favorable for double-diffusive processes. However, measured values of the density ratio R&rgr; over the shelf imply weak vertical mixing (Kv ~10-1 cm-1), which is consistent with heat and salt fluxes into the persistent cold pool. Convergent circulation driven by cabbeling and vertical mixing enhanced by double-diffusion at the outer edge of the cold pool may be responsible for the abrupt deepening of the chlorophyll a maximum layer.