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submerged ice which is attached to the bottom.

an ocean and ice circulation pattern in the Beaufort Sea, north of Alaska. This gyre moves in a clockwise direction, fed by an average high-pressure system that fosters anti-cyclonic winds. Ice that forms in or drifts into the Beaufort Gyre has historically remained in the Arctic ice system for years, accumulating snow and thickening each winter. Beginning in the late 1990s, the ice began melting away while in the southern parts of the gyre, before completing the circulation.

a long area of pack ice from a few km to more than 100 kilometers in width.

situation of a vessel surrounded by ice and unable to move.

an extensive crescent-shaped indentation in the ice edge, formed either by wind or current.

a lead closed off on all sides within the ice pack.

accumulation of floating ice made up of fragments not more than 2 meters (6.6 feet) across, the wreckage of other forms of ice.

small droplets of highly saline water that form in pockets between ice crystals, as sea ice forms and expels salt into the underlying ocean water.

smooth hills of ice that form on the bottom of sea ice from eroding keels, particularly during the summer melt.

composed of close ice that is mostly in contact; ice cover 7/10ths to 9/10ths.

an advanced form of new ice that forms as a stable sheet with a smooth bottom surface.

pack ice in which the floes are frozen together; ice cover 10/10ths.

any fracture or rift in floating ice not sufficiently wide to be described as a lead.

ice that contains sediments stirred up and tangled in the ice as it grows.

ice that moves from winds, currents, or other forces.

ice that is anchored to the shore or ocean bottom, typically over shallow ocean shelves at continental margins; fast ice is defined by the fact that it does not move with the winds or currents.

a process by which currents or winds push around thin ice so they slide over each other.

floating ice of no more than one year's growth developing from young ice; thickness from 0.3 to 2 meters (1 to 6.6 feet); characteristically level where undisturbed by pressure, but where ridges occur, they are rough and sharply angular.

a navigable passage between pack ice and fast ice.

ice that is pushed into the underlying ocean water by the weight of thick snow cover on its surface; the salty ocean water floods the snow cover and creates a salty, slushy layer; flooded sea ice is more common in the antarctic because of more snowfall and thinner sea ice than in the arctic.

small needle-like ice crystals, typically 3 to 4 millimeters in diameter, suspended in water, that represent the first stages of sea ice growth; they merge under calm conditions to form thin sheets of ice on the surface, frazil crystals consist of nearly pure fresh water.

fine spicules or plates of ice in suspension in water.

from the point of view of the submariner, an icey canopy containing many large ice skylights or other features which permit a submarine to surface; there must be more than ten such features per 37 kilometers (30 nautical miles) along the submarine's track.

crystals of ice that form when water vapor becomes a solid (bypassing the liquid phase) and deposits itself on the sea ice surface; frost flowers roughen the surface and dramatically affect its electromagnetic signal.

a very thin, soupy layer of frazil crystals clumped together, which makes the ocean surface resemble an oil slick.

a category of young ice 15 to 30 centimeters (6 to 12 inches) thick, named for its color.

from the point of view of the submariner, an ice canopy containing no large ice skylights or other features which permit a submarine to surface.

[sea ice] pressure process by which floating ice becomes broken up into hummocks.

a floe smaller than 20 meters (66 feet) across.

pack ice from the point of view of the submariner.

a concentration of sea ice, covering 100's of square kilometers, which is found in the same region every summer.

the fraction of an area that is covered by sea ice.

the total area covered by some amount of ice, including open water between ice floes; ice extent is typically reported in square kilometers.

from the point of view of the submariner, a downward-projecting ridge on the underside of the ice canopy; the counterpart of a ridge; ice keels may extend as much as 50 meters (55 yards) below sea level.

a brittle, shiny crust of floating ice, formed on a quiet surface by direct freezing or from grease ice, usually in water of low salinity; thickness less than 5 centimeters (2 inches); easily broken by wind or swell, commonly breaking into rectangular pieces.

from the point of view of the submariner, thin places in the ice canopy, usually less than 1 meter (3.3 feet) thick and appearing from below as relatively light, translucent patches in dark surroundings; the under-surface of an ice skylight is normally flat; ice skylights are called large if big enough for a submarine to attempt to surface through them (120 meters, 131 yards), or small if not.

a narrow fringe of ice attached to the coast, unmoved by tides and remaining after the fast ice has broken free.

a measure of the compactness, or strength of the ice; plays an important role in the deformation of the ice and formation of features such as ridges and leads.

the part of a ridge below the ocean surface; wind, ocean currents, and other forces can push sea ice into piles that rise and form small mountains below the level sea ice surface.

a polynya that forms from strong winds in a persistent direction that push the ice away from a barrier (the coast, fast ice, a grounded iceberg, or an ice shelf).

long, linear areas of open water that range from a few meters to over a kilometer in width, and tens of kilometers long; they develop as ice diverges, or pulls apart.

a lead that forms between drift ice and the coast.

floating ice with a flat surface which has never been hummocked.

a part of the seasonal ice zone that varies in width (100 to 200 kilometers, 62 to 124 miles) that extends from the ice edge into the ice pack, where waves and swells affect the ice; often characterized by highly variable ice conditions; in general, it is wider in the Antarctic than the Arctic.

pools of melted snow and ice on the sea ice surface created during the summer melt.

ice that has survived at least one melt season; it is typically 2 to 4 meters (6.6 to 13.1 feet) thick and thickens as more ice grows on its underside.

a general category of ice that consists of frazil, grease ice, slush, and shuga.

a thin sheet of smooth, level ice less than 10 centimeters (4 inches) thick; appear darkest when thin.

ice is said to nip when it forcibly presses against a ship which is beset; a vessel so caught, though undamaged, is said to have been nipped.

sea ice more than 2-years-old, up to 3 meters (10 feet) or more thick; hummocks on old ice are even smoother than in second-year ice, and the ice is almost salt-free; when old ice is bare of snow, it is blue and lacks the greenish tint of second-year ice.

a lead that connects two open bodies of water; ships can traverse between them through this lead; it also refers to a lead where open water is found, or a lead that has not completely frozen.

composed of floes seldom in contact and with many leads; ice cover 4/10ths to 6/10ths.

a large area of freely navigable water in which floes may be present in concentration under 1/10th; if there is no sea ice present, the area may be termed open water, even though icebergs are present.

ice that is not attached to the shoreline and drifts in response to winds, currents, and other forces; some prefer the generic term drift ice, and reserve pack ice to mean drift ice that is closely packed.

pieces of new ice approximately circular, up to 10 centimeters (4 inches) thick and 0.03 to 3 meters (0.1 to 9.8 feet) in diameter, with raised edges that form from rubbing against each other; formed from the freezing together of grease ice, slush or shuga, or the reaking up of ice rind or nilas.

a collection of pack ice, less than 10 kilometers (6.2 miles) across, whose limits can be seen from the masthead.

a region that is covered with sea ice year-round; most of the sea ice in the permanent ice zone is multiyear ice, but younger ice and open water may still be present; the permanent ice zone is what remains in summer after all melting has occurred (often called the summer minimum extent).

a general term for floating ice which has been squeezed together and in places forced upwards; includes rafted ice, telescoped ice, hummocked ice and ridge ice.

process that occurs when wind, ocean currents, and other forces push sea ice around into piles that rise and form small mountains above the level sea ice surface; ridges are initially thin and transparent with very sharp edges from blocks of ice piling up; also see keels.

deformed sea ice in which one piece has overridden another; also called telescoped ice.

a process by which currents or winds push around thin ice so they slide over each other; also called finger rafting.

piled ice formed by ridging.

process that occurs when wind, ocean currents, and other forces push sea ice around into piles that rise and form small mountains above the level sea ice surface; ridges are initially thin and transparent with very sharp edges from blocks of ice piling up; also see keels.

the part of a ridge above sea level; like a sail on a sailboat, it catches wind and moves the ice.

any form of ice found at sea which has originated from the freezing of sea water.

see ice extent.

the day of the year when the sea ice covers the largest area of the Arctic or Antarctic.

the day of the year when the sea ice covers the smallest area of the Arctic or Antarctic

an area of ocean that extends from the permanent ice zone to the boundary where winter sea ice extent is at a maximum; here, sea ice is present only part of the year; this zone primarily consists of first-year ice.

sea ice which has not melted in the first summer of its existence; by the end of the second winter, it attains a thickness of 2 meters (6.6 feet) or more; it stands higher out of the water than first-year ice; summer melting has somewhat smoothed and rounded the hummocks, which accentuation of minor relief by differential melting may have caused others to develop; bare patches and puddles are usually greenish-blue.

a polynya that forms from the upwelling of warm (above-freezing) ocean water from lower depths; these can form in mid-ocean areas, far from coasts or other barriers.

a stretch of navigable water between pack ice and the shore.

a form of new ice, composed of spongy, white lumps a few cm across, that tend to form in rough seas; they resemble slushy snow balls.

very old, thick sea ice that forms in fjords; it often resembles glacial ice, because snow can pile up on the ice over many years.

thick ridges that become grounded during the winter and become part of the fast ice zone; while the rest of the fast ice melts during the summer, a stamukhi remains throughout the summer attached to the ocean bottom.

a long narrow area of pack ice, about 1 kilometer (0.6 mile) or less in width, usually composed of small fragments detatched from the main mass of ice, and run together under the influence of wind or current.

the permanent ice zone that remains in summer after all melting has occurred.

deformed sea ice in which one piece has overridden another; also called rafted ice.

the thickness at which ice no longer grows because it is so thick that heat from the ocean can no longer be conducted through the ice; it may take several years of growth and melt for ice to reach an equilibrium thickness.

pack ice in which the floes are tightly packed but not frozen together, with very little, if any, sea water visible; ice cover practically 10/10th.

pack ice composed of loose, widely spaced floes; ice cover 1/10th to 3/10th.

a general category of ice that represents the transition between nilas and first-year ice; usually 10 to 30 centimeters (4 to 12 inches) thick.

References:

American Meteorological Society. "Glossary of Meteorology." http://amsglossary.allenpress.com/glossary [Accessed August 16, 2006].

Beltz, Ellin. "Glossary of Glacier Terms." http://ebeltz.net/glacier/glacglos.html [Accessed August 16, 2006].

CO2 Science. "Global Change Dictionary." http://www.co2science.org/scripts/CO2ScienceB2C/education/dictionary/define.jsp [Accessed December 19, 2006].

Ferguson, Sue A., 1992. Glaciers of North America: A field guide. Golden, CO: Fulcrum Publishing.

Huschke, Ralph E., ed. 1959. Glossary of Meteorology. Boston: American Meteorological Society.

Khromov, S. P. and L. A. Mamontova, 1974. Glossary of Meteorology. Lenningrad: Gidrometeoizdat.

Van Everdingen, ed. 1994. Multilanguage Glossary of Permafrost and Related Ground-Ice Terms. Alberta: Arctic Institute of North America.

"Wikipedia." http://en.wikipedia.org/wiki/Main_Page [Accessed August 16, 2006].

1992. International Meteorological Vocabulary. Geneva, Switzerland: World Meteorological Organization.

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