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Cryosphere glossary


(1) combined processes (such as sublimation, fusion or melting, evaporation) which remove snow or ice from the surface of a glacier or from a snow-field; also used to express the quantity lost by these processes (2) reduction of the water equivalent of a snow cover by melting, evaporation, wind and avalanches.

the area of a glacier where more glacier mass is lost than gained.
depressions in the snow surface caused by the sun or warm, gusty wind.
mound or layer of moraine in the ablation zone of a glacier; the rock has been plucked from the mountainside by the moving glacier and is melting out on the ice surface.
period during which glaciers lose more mass than they gain; usually coincides with summer.
area or zone of a glacier where snow and ice ablation exceed accumulation.
the difference, taken without regard to sign, between the values of two variables
the difference between the measured or inferred value of a quantity and its actual value.
(1) the ratio of the mass of water vapor to the volume occupied by a mixture of water vapor and dry air (2) mass of water contained in a unit volume of moist air.
growth of a cloud or precipitation particle by the collision and union of a frozen particle (ice crystal or snowflake) with a super-cooled liquid droplet which freezes on impact.
all processes by which snow or ice are added to a glacier, this is typically the accumulation of snow, which is slowly transformed into ice; other accumulation processes can include avalanches, wind-deposited snow, and the freezing of rain within the snow pack.
area of a glacier where more mass is gained than lost.
period during which a glacier gains more mass than it loses; usually coincides with winter.
area of a glacier where more mass is gained than lost.
the extent to which the readings of an instrument approach the true value of the calculated or measured quantities, supposing that all possible corrections are applied.
rain or snow containing acidic substances, resulting from the atmospheric pollution mainly with sulfur and nitrogen; acid precipitation has a lower pH than unpolluted rain.
a foundation pile on which a cold air refrigeration system has been installed to remove heat from the ground.
special design and construction methods used for engineering works in permafrost areas where permafrost degradation cannot be prevented.
an ice wedge that is growing as a result of repeated (but not necessarily annual) winter cracking.
the layer of ground that is subject to annual thawing and freezing in areas underlain by permafrost; also known as seasonal frost.