Most of the ocean is very cold (average temperature is just 4C!) and most of that cold water comes from the shallow seas next to the Antarctic coast. In a recent paper (https://www.nature.com/articles/s41598-021-81793-5) it is shown show that the very dense water is moving out of the Ross Sea in two pulses a year at equinoxes when the tides due to the sun are weak. These results suggest the tides control how this cold water enters the global ocean.
