Glossary

Cold fall winds are referred to as katabatic winds. They form when cold air masses from inland ice flow down steep slopes toward the coast, warming in the process. These winds often follow periods characterised by intensive heat emissions. The air cools over the ice of the Antarctic Plateau or glaciers, causing its density to rise. The difference in pressures between this cool air and its “warmer” surroundings produces cold, katabatic fall winds. Katabatic winds play a central role in the formation of Antarctic sea ice and therefore the formation of Antarctic Bottom Water, not to mention the formation of coastal polynyas (openings in the sea ice). The phenomenon is especially pronounced near the extensive ice-shelf fields of the Ross Sea and Weddell Sea. Antarctic fall winds are the most powerful winds in the world and can reach speeds of up to 300 km/h.