- المجال: Weather
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The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. Founded in 1919, AMS has a membership of more than 14,000 professionals, ...
The vortex in the lower stratosphere over the Antarctic in austral winter.
Industry:Weather
The water mass of the Antarctic Zone. It has a temperature of 0. 0° to −1. 9°C and a salinity below 34 psu.
Industry:Weather
The southern front of the Antarctic Circumpolar Current, also known as the antarctic convergence, that separates the Antarctic Zone in the south from the polar frontal zone in the north. It is characterized by sea surface temperatures near 5°–6°C and a salinity minimum of 33. 8– 34. 0 psu produced by high rainfall.
Industry:Weather
A phenomenon discovered in the mid-1980s that occurs in the winter–spring lower stratosphere over Antarctica. Through a sequence involving heterogeneous chemistry on polar stratospheric clouds and (intermittent) illumination by sunlight, much or all of the ozone in the lower stratosphere can be photochemically destroyed. Halogen species (chlorine and bromine) contained in fairly robust molecules are transformed via heterogeneous reactions into molecules that are easily photolyzed resulting in atomic or monoxide halogens that lead to chemical destruction of ozone. This phenomenon also occurs over the Arctic, although to a lesser extent because of a lower incidence of polar stratospheric clouds.
Industry:Weather
The semipermanent, semicontinuous front between the antarctic air of Antarctica and the polar air of the southern oceans; generally comparable to the arctic front of the Northern Hemisphere.
Industry:Weather
A water mass identified by a salinity minimum found at depths between 700 and 1000 m in the Southern Hemisphere. It is formed at various locations along the Antarctic Polar Front and through deep winter convection east of southern Chile and south of the Great Australian Bight. It enters all oceans with the Antarctic Circumpolar Current and spreads toward the equator between the central water and the deep water.
Industry:Weather
The region near 60°S, south of the Antarctic Polar Front, where high-salinity North Atlantic Deep Water upwells from 2500 m to just below the surface and mixes with low- salinity Antarctic Surface Water.
Industry:Weather
An eastward flowing current, also known as the West Wind Drift, that circles Antarctica and extends from the surface to the ocean floor. With a volume transport of 130 Sv (130 × 106 m3s−1) it is the largest of all ocean currents. Current speed in the ACC is comparatively modest (0. 1 m s−1, but larger in fronts), the large transport being achieved by the current's great depth. Seventy-five percent of the transport occurs in the polar and subantarctic fronts that make up only 20% of the ACC area. Interannual variability is about 15% of the mean but can reach 40% on occasions. The ACC is influenced by bottom topography, which causes deflections from its general westward path and eddy formation, particularly at the Scotia Ridge, the Kerguelen Plateau, and the Macquarie Ridge. The eddies are instrumental for the poleward transport of heat across the current, which would otherwise block meridional heat transfer.
Industry:Weather
