NIWA physical oceanographer Dr Mike Williams talks about the world's largest current – the Antarctic Circumpolar Current (ACC) – and its influence on the 'oceanography' (ocean characteristics) south of New Zealand.
The ACC spans the Southern Ocean encircling Antarctica. Its large volume of deep cold water has a major influence on the Earth's ocean and climate systems. He describes its influence on the oceanography around two subantarctic islands: Macquarie and Campbell Islands.