[screenshot nullschool ocean-currents-ssta]
Inflow from the Pacifc the main flow show drifting east and a general value 0.8-0.9 sverdrup containing 10-Tw/winter, 20-Tw/summer heat-flux of less dense water from freshwater runoff creating a head-height of 40-50cm helping to melt sea-ice from below.
This flow contributes to outflow to the Atlantic along with a new freshwater and atmospheric pattern now exacerbated by a large cyclone over the Beaufort, being an inflow this creates a circulation behind the "waterfall" to bring in Atlantic water from the eastern side.
The bathtub analogy a tub full to overflow and you add a hose to the far end offset from center, that creates a circulation to the outflow, stop the hose the circulation dies.
This has critical thermal implications for cooling the planet without regard to emission controls.