Definitions

from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun Granular, partially consolidated snow that has passed through one summer melt season but is not yet glacial ice.

from The Century Dictionary.

  • noun A name given to snow accumulated in the highest parts of mountain ranges on which glaciers occur, while such snow is in a granular condition, and before, in its downward movement, it has been fully consolidated into ice.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun A type of old snow which has gone through multiple thaw and refreeze cycles and thus is made of numerous small icy grains, though it is not nearly as saturated with water as snow-cone slush is; can be hard or somewhat soft depending on recent and current weather conditions.

Etymologies

from The American Heritage® Dictionary of the English Language, 4th Edition

[German, from German dialectal, of last year, from Old High German firni, old.]

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Examples

  • The line that separates these two areas is called the firn limit or snow line.

    Glacier 2008

  • Thus we must discriminate between two distinct parts of the ice fields; that is, first, the snow which originally fell—called firn in Switzerland—above the snow line, covering the slopes of the peaks as far as it can hang on to them, and filling up the upper wide kettle-shaped ends of the valleys forming widely extending fields of snow or firnmeere.

    Ice and Glaciers 1909

  • The glaciers that make up this alpine cryosphere are actually constantly moving "rivers of ice" that begin in their "accumulation zones" high on mountainsides, where snows fall and are compressed into "firn," the blue ice that gives glaciers their air of frozen purity.

    The Most Endangered Glaciers 2010

  • Three or four awkward bits were circumvented; a couloir or gully full of snow mounted; and then there was a long climb up a moderate slope toward where a ridge of rocks stood out sharply, with snow sloping down on either side, the ridge running up far into the mountain; but before they could get to this a deep bed of old snow -- "firn" Melchior called it -- a great sheet, like some large white field, had to be passed.

    The Crystal Hunters A Boy's Adventures in the Higher Alps George Manville Fenn 1870

  • The critiques of Jaworowski on the shift were addressed by Hans Oeschger 1995, who pointed out that the ice core record shift was done in accordance with theoretical estimates of the rate of diffusion in gases in firn, and that these theoretical estimates were confirmed by isotopic enrichment in line with theory.

    Archive 2010-03-01 EliRabett 2010

  • The critiques of Jaworowski on the shift were addressed by Hans Oeschger 1995, who pointed out that the ice core record shift was done in accordance with theoretical estimates of the rate of diffusion in gases in firn, and that these theoretical estimates were confirmed by isotopic enrichment in line with theory.

    Eli can retire 1 EliRabett 2010

  • Water is also stored in permanent snowfields and firn (compact, granular snow that is over one year old) fields, perched lakes (lakes that are raised above the local water table by permafrost), and as permafrost itself.

    Terrestrial Water Balance in the Arctic 2009

  • Accumulation then causes a further increase in density, modifying the firn into glacier ice, as the lower layers of firn are compressed by the weight of the layers above.

    Glacier 2008

  • When this process happens year after year, a number of layers of firn can accumulate.

    Glacier 2008

  • If the névé survives the ablation that occurs during the summer months it is called firn.

    Glacier 2008

Comments

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  • Granular, partially consolidated snow that has passed through one summer melt season but is not yet glacial ice. Also called old snow.

    February 12, 2008