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

permafrost in which part or all of the total water content is unfrozen because of freezing-point depression due to a high dissolved-solids content of the pore water.

(1) a general property of aqueous solutions caused by the alkali, alkaline earth, and metal salts of strong acids (Cl, SO4 and NO3) that are not hydrolyzed (2) in soil science, the ratio of the weight of salt in a soil sample to the total weight of the sample.

a wedge-shaped body of sand produced by filling of a thermal contraction crack with sand either blown in from above or washed down the walls of the crack.

a polygon outlined by sand wedges underlying its boundaries.

complex, fragile shapes of snow on top of sea ice that resemble sand dunes; they form parallel to the prevailing wind direction; sastrugi can also form on snow cover over land.

the condition in which the partial pressure of any fluid constituent (water in the atmospheric air) is equal to its maximum possible partial pressure under the existing environmental conditions, such that any increase in the amount of that constituent will initiate within it a change to a more condensed state; evaporation ceases under such conditions.

the maximum amount of water vapor necessary to keep moist air in equilibrium with a surface of pure water; this is the maximum water vapor the air can hold for any given combination of temperature and pressure.

(1) a series of marks at regular intervals for the purpose of measuring (scale of an instrument, for example, a thermometer) (2) system of units for measuring ( 3) proportion between the size of something and the map, diagram, etc. which represents it (4) order of magnitude of a phenomenon or of a meteorological parameter.

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

evaporation fog formed when water vapor is added to air which is much colder than the vapor's source; most commonly, when very cold air drifts across relatively warm water; also called steam fog.

temperature of the water film at the sea surface.

the atmospheric pressure at mean sea level, either directly measured or, most commonly, empirically determined from the observed station pressure.

the cumulative number of degree-days below 0 degrees Celsius, calculated as the arithmetic sum of all the negative and positive mean daily air temperatures (degrees Celsius) for a specific station during the time period between the highest point in the fall and the lowest point the next spring on the cumulative degree-day time curve.

the occurrence of ground temperatures below 0 degrees Celsius for only part of the year; see also active layer.

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.

(1) snow that accumulates during one season (2) snow that lasts for only one season.

the cumulative number of degree-days above 0 degrees Celsius, calculated as the arithmetic sum of all the positive and negative mean daily air temperatures (degrees Celsius) for a specific station during the time period between the lowest point in the spring and the highest point the next fall on the cumulative degree-day time curve.

ground that freezes and thaws annually.

the active layer in areas without permafrost.

ground that thaws and refreezes annually.

the active layer in permafrost areas.

the uppermost layer of the permafrost which undergoes seasonal phase changes due to the lowered thawing temperature and freezing-point depression of its pore water.

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.

alternating bands of light and dark at the firn limit of a glacier; the light bands are usually young and lightest at the highest level up-glacier, becoming increasingly older and darker as they progress down-glacier.

ice in discrete layers or ice lenses, formed by ice segregation.

the ratio of the rate of moisture migration to the temperature gradient in a frozen soil near the 0 degrees Celsius isotherm.

high pressure area largely predominate during a major portion of the year where an anticyclone appears on the mean monthly pressure charts.

slowly moving or motionless cyclone.

same as enthalpy; the heat absorbed or transmitted by a substance during a change of temperature which is not accompanied by a change of state; used in meteorology in contrast to latent heat.

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.

an isolated block of ice that is formed where the glacier surface is fractured.

in geology, describes the compressive strength (ability to withstand pushing forces) of soils; results from two internal mechanisms: cohesion between soil particles, and friction caused by contact between particles; variable among different soils.

a screen to shield a rain-gauge from the influence of the wind, or to shield a thermometer against insolation.

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

the failure strength of a material under a short-term loading (e.g. up to about 10 minutes in a uniaxial compression test).

in meteorology, a term used loosely to distinguish radiation in the visible and near-visible portions of the electromagnetic spectrum (roughly 0.4 to 4.0 microns in wavelength) from longwave (terrestrial) radiation.

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.

an area of high pressure which forms over Siberia in winter, and which is particularly apparent on mean charts of sea-level pressure.

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.

a passive heat transfer device, filled with either a liquid or a gas, installed to remove heat from the ground.

the bonding together of ice crystals.

(1) (United States) frozen raindrops that bind on impact with the ground (2) (elsewhere) a mix of rain and snow, a mix of rain and hail, or melting snow.

mass movement of earth material down a slope; includes landslides, mudslides, debris flows, avalanches, etc; speed of movement can be sudden and catastrophic or slow.

a mixture of snow and grease ice.

common near the snow line on a relatively flat portion of a glacier where melting snow forms slush.

currently used as a synonym for general air pollution; it was originally created by combining the words smoke and fog.

(1) an ice particle formed by sublimation of vapor in the atmosphere (2) a collection of loosely bonded ice crystals deposited from the atmosphere; high density snow (greater than 550 kilograms per cubic meter; 34 pounds per cubic foot) is called firn if it is older than one year.

horseshoe-shaped snowdrift, with the ends pointing down-wind.

a specially constructed board used to identify the surface of snow that has been recently covered by snowfall.

an arch formed by snow which has drifted aross a crevasse, forming first a cornice, and ultimately a covering which may completely obscure the opening.

a sample of snow, either just the freshly fallen snow or the combined old and new snow on the ground, obtained by pushing a cylinder down through the snow layer and extracting it.

(1) in general, the accumulation of snow on the ground surface (2) the areal extent of snow-covered ground, usually expressed as percent of total area in a given region.

the mass of snow per unit volume which is equal to the water content of snow divided by its depth.

the combined total depth of both old and new snow on the ground.

the total land area covered by some amount of snow; typically reported in square kilometers.

snow that falls for short durations and which often changes in intensity; flurries usually produce little accumulation.

precipitation in the form of very small, white opaque ice particles; they resemble snow pellets but are more flattened and elongated, with a diameter less than 1 mm; the solid equivalent of drizzle.

a layer of ice crystals with similar size and shape.

the minimum elevation of snow lying on the ground or glacier surface; the snow line at the end of an ablation season marks a glacier's current equilibrium line.

the downward force on an object or structure caused by the weight of accumulated snow.

relatively small area of snow cover remaining after the main snowmelt period.

precipitation in the form of small, white opaque ice particles; resemble ice grains, but are round (sometimes conical) and about 2-5 mm in diameter.

roll-like snow formation, caused by a unique combination of snow, wind, temperature and moisture

a brief, but intense fall of snow that greatly reduces visibility and which is often accompanied by strong winds.

the water content obtained from melting.

an oligochaete worm that lives on temperate glaciers or perennial snow; there are several species that range in color from yellowish-brown to reddish-brown or black; they are usually less than 1 millimeter (0.04 inch) in diameter and average about 3 millimeters (0.1 inch) in length; some feed off red algae.

a bright white glare on the underside of clouds, produced by the reflection of light from a snow-covered surface; snowblink is lighter than ice blink, and much lighter than land sky or water sky.

very intense showers of snow, often of short duration, that greatly restrict visibility and produce periods of rapid snow accumulation.

an accumulation or bank of snow formed when wind blows snow against an obstruction; often considerably thicker than the surrounding snowcover.

a semipermanent mass of firn formed by drifted snow behind obstructions or in the ground; also called a catchment glacier or a drift glacier.

the depth of new snow that has accumulated since the previous day or since the previous observation.

a cluster of ice crystals that falls from a cloud.

melting of the snowcover, and also the period during which melting of the snow cover occurs at the end of the winter.

the total snow and ice on the ground, including both new snow and the previous snow and ice which have not melted.

strong wind with snow.

a wedge-shaped body of soil that is different in structure and texture from the surrounding soil.

the total electromagnetic radiation emitted by the sun.

slow downslope flow of saturated unfrozen earth materials.

a fan-like deposit at the base of a slope, produced by solifluction.

geomorphological features of varying scale produced by the process of solifluction.

an isolated, tongue-shaped solifluction feature, up to 25 meters (27 yards) wide and 150 meters (164 yards) or more long; formed by more rapid solifluction on certain sections of a slope showing variations in gradient.

a broad deposit of nonsorted, water-saturated, locally derived materials that is moving or has moved downslope.

a low step, or bench, with a straight or lobate front, the latter reflecting local differences in the rate of solifluction movement.

the point in time when the vertical rays of the sun are striking either the Tropic of Cancer (23 degrees, 30 minutes N, the summer solstice in the northern hemisphere) or the Tropic of Capricorn (23 degrees, 30 minutes S, the winter solstice in the northern hemisphere); represents the longest or shortest day of the year; in the northern hemisphere, the summer solstice falls on or about 21 June, and the winter solstice on or about 22 December.

a patterned ground form that is equidimensional in several directions, with a dominantly circular outline, and a sorted appearance commonly due to a border of stones surrounding a central area of finer material.

a type of patterned ground with cells that are equidimensional in several directions, neither dominantly circular nor polygonal, with a sorted appearance commonly due to borders of stones surrounding central areas of finer material.

a patterned ground form that is equidimensional in several directions, with a dominantly polygonal outline, and a sorted appearance commonly due to a border of stones surrounding a central area of finer material.

a patterned ground feature with a step-like form and a downslope border of stones embanking an area of relatively fine-grained bare ground upslope.

patterned ground with a striped and sorted appearance, due to parallel strips of stones and intervening strips of finer material, oriented down the steepest available slope.

90° S latitude; one of the two points where the Earth's axis of rotation meets the Earth's surface (the other being the north pole, diametrically opposite).

the amount of heat required to raise the temperature of a unit mass of a substance by one degree.

the mass of water vapor per unit mass of air, including the water vapor (usually expressed as grams of water vapor per kilogram of air).

a crevasse pattern that forms where ice slowly spreads out sideways; commonly found near a glacier terminus.

(1) (North American usage) permafrost underlying 10 - 50% of the exposed land surface (2) (Russian usage) permafrost underlying 5 - 30% of the exposed land surface.

either of the two points of intersection of the sun's apparent annual path and the plane of the earth's equator; in the northern hemisphere, the spring (vernal) equinox falls on or about 21 March, and the autumnal equinox on or about 22 September.

air mass having static stability in its lower layers; it is free from convection, has a low degree of turbulence and may have stratiform clouds or fog, or no clouds.

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.

Statistical measurement of the variation in a distribution: In science, standard deviation serves as measure of the spread of the data, or how likely a data point will fall close to the mean.

a mineral soil showing little or no evidence of cryoturbation, with permafrost within 1 meter (3.3 feet) below the surface.

atmospheric pressure observed at a station.

evaporation fog formed when water vapor is added to air which is much colder than the vapor's source; most commonly, when very cold air drifts across relatively warm water; also called sea smoke.

in meteorology, a basic fluid flow which exerts a strong influence upon the direction of movement of disturbances embedded in it; in the atmosphere, it is usually an air flow in the middle or upper troposphere which govern directions of the disturbances at low levels.

a type of nonsorted circle developed in gravelly materials.

the downslope border of stones along a sorted step, embanking an area of relatively fine-grained bare ground upslope.

a solifluction lobe with a stony front.

a solifluction terrace with a stony front.

a fissure at the junction between an inland ice sheet, ice piedmont or ice rise and an ice shelf, the latter being subject to the rise and fall of the tide.

a principal low-level cloud type (cloud genus), predominantly stratiform, in the form of relatively low gray and/or whitish layer, sheet or patch; its elements are often arranged in bands or rolls that lie across the wind; light rain, snow, or sleet may fall from stratocumulus.

the boundary layer between the stratosphere and the mesosphere at about 50 to 55 kilometers (31 to 34 miles).

a layer of the Earth’s atmosphere, between the troposphere and mesosphere, that is stratified in temperature such that cooler layers are closer to the Earth’s surface, and warmer layers are higher up (opposite the pattern of the troposphere near the Earth’s surface); situated between about 10 to 50 kilometers (6 to 31 miles) in altitude above the surface of the moderate latitudes; at the poles, it starts at about 8 km in altitude; composition is basically the same as that of the lower atmosphere, with the addition of ozone.

a principal low-level cloud type (cloud genus) in the form of a low-altitude, light to dark gray cloud layer with a rather uniform base; generally diffuse and dull; this cloud formation has little structure and looks like fog, except that it is above the ground, stratus does not usually produce precipitation, but when it does occur, it is in the form of minute particles, such as drizzle, ice crystals, or fine snow grains.

a peatland with roughly parallel narrow ridges of peat dominated by fenland vegetation interspersed with slight depressions, many of which contain shallow pools.

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.

permafrost beneath a glacier.

a layer or body of unfrozen ground beneath a glacier in an area with permafrost.

the transition of a substance from the solid phase directly to the vapor phase, or vice versa, without passing through an intermediate liquid phase.

ice formed by reverse sublimation of water vapour on cold surfaces.

water occurring in the noncryotic ground below the permafrost.

a glacier whose temperature regime is between polar and temperate; usually predominantly below freezing, but could experience extensive summer melt.

permafrost occurring beneath the sea bottom.

a layer or body of unfrozen ground beneath the seabottom, and forming part of the subsea permafrost.

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

ablation hollows that develop during intense sunshine.

dark spot on the sun, with cooler-than-average temperatures and strong magnetic activity

the condition when a liquid remains in the liquid state even through its temperature is below its freezing point.

cooling of a liquid to a temperature below its freezing point, without causing solidification.

the condition which occurs in the atmosphere when the relative humidity is greater than 100%.

water occurring in unfrozen ground above perennially frozen ground.

a distinct soil micromorphology, resulting from the effects of freezing and thawing processes, in which coarser soil particles have vertical or near-vertical orientation.

the cumulative number of degree-days below 0 degrees Celsius for the surface temperature (of the ground, pavement, etc.) during a given time period.

the deposition (sublimation) of ice crystals on a surface which occurs when the temperature of the surface is colder than the air above and colder than the frost point of that air.

a meteorological observation made on the earth's surface, in contrast with an upper-air observation.

the ambient temperature indicated by a thermometer exposed to the air but sheltered from direct solar radiation, or placed in an instrument shelter 1.5 - 2.0 meters (5.0 - 6.6 feet) above ground; also called air temperature.

wind blowing near the earth's surface; it is measured, by convention, at a height of 10 meters (33 feet) above ground in an area where the distance between the anemometer and any obstruction is at least 10 times the height of the obstruction.

a glacier that experiences a dramatic increase in flow rate, 10 to 100 times faster than its normal rate; usually surge events last less than one year and occur periodically, between 15 and 100 years.

a substance dispersed throughout another substance; also called suspended phase.

ground ice developed during the formation of syngenetic permafrost.

an ice wedge developed during the formation of syngenetic permafrost.

permafrost that formed through a rise of the permafrost table during the deposition of additional sediment or other earth material on the ground surface.

the study of the synoptic observation data plotted on synoptic charts aimed at analysis of the atmospheric disturbances (for example, fronts, cyclones, and anticyclones).

a weather chart reflecting the state of the atmosphere over a large area at a given moment.

a code approved by the World Meteorological Organization, by which meteorological elements observed at the earth's surface at synoptic times are encoded in groups of five figures and transmitted internationally through the GTS (Global Telecommunications System).

hour (UTC - Coordinated Universal Time) determined by international agreement at which meteorological observations are made simultaneously throughout the world; the primary synoptic hours are every six hours, commencing at 00:00 UTC.

the study and analysis of synoptic weather information (synoptic charts, synoptic weather observations); thus, it is a study of macro-scale atmospheric processes, as well as weather prediction based on results of synoptic studies.

an observation made at periodic times (usually at 3-hour and 6-hour intervals specified by the World Meteorological Organization) of sky cover, state of the sky, cloud height, atmospheric pressure at sea level, temperature, dew point, wind speed and direction, amount of precipitation, hydrometeors and lithometeors, and special phenomena that prevail at the time of the observation or observed since the previous specified observation.

the scale of the high- and low-pressure systems of the lower atmosphere; dimensions typically range from 1000 to 2500 kilometers (620 to 1550 miles; synoptic-scale circulation).

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