I’m going to have to watch and rewatch this to really grasp – hypnotic and revealing.
We tend to think of the ocean as a vast bowl, filled with salty water. But it might be more appropriate to think of that water as a particularly salty layer dip in an uneven baking dish.
The very bottom layer of this “dip” is unevenly concentrated at one end of the ocean basin, near Antarctica. This layer of water is known, fittingly, as bottom water. It forms near the surface, as Antarctica’s ice shelves freeze in the winter. The water that freezes pushes out many salt particles, shoving them deeper into the ocean, making the water below the ice shelf denser and saltier. This cold, salty water sinks to the bottom of the Southern Ocean, falling into the abyss in underwater waterfalls.
The formation and movement of Antarctic bottom water is hugely important for ocean circulation, but because Antarctica is a difficult place to work, scientists have a hard time observing it directly.
Thankfully, they have computers to help. Researchers at the Australian Research Council’s Centre of Excellence for Climate System Science used a supercomputer called Raijin to create simulations of how bottom water behaves using data collected in the field. Even with a supercomputer, it took 7 hours to produce one second of the above footage.
!