snow line

Also found in: Dictionary, Thesaurus, Wikipedia.
Related to snow line: wind

snow line,

altitude above which or latitude beyond which snow does not melt in summer (usually called the permanent snow line), or, in winter, the line to which snow extends at a given point in time. Factors affecting the location of the snow line are the quantity of snowfall, the steepness of the slope on which snow rests, the exposure of an area to the sun and prevailing winds, the type and velocity of the winds, and the presence or absence of large bodies of water. The level of the snow line is much lower in winter than in summer. It is also affected by distance from the equator, along which it is found at an altitude of c.3 mi (5 km); in polar regions it is at sea level.

Snow Line


the line on the earth’s surface above which the accumulation of solid atmospheric precipitation is greater than the melting and evaporation of the precipitation. A distinction is made between the climatic snow line (the highest position at the end of the summer) and the seasonal, or temporary, line.

The snow line is lower in cold and wet regions and higher in warm and dry ones. In the antarctic it descends to sea level, and in the arctic it is several hundred meters above sea level. It reaches its greatest elevation in the dry tropical and subtropical regions (up to 7 km on the Tibetan Highlands), dropping to 4.4 km at the equator. The elevation of the snow line depends on local conditions; for example, some relief forms may give protection against the wind and promote the accumulation of snow or protect the surface against solar radiation and diminish thawing. The level of the climatic snow line corresponds to the position of the line on a horizontal, unshaded surface. The lower boundary of perennial snowfields is called the orographic snow line; in some places it is significantly lower than the climatic snow line. The Urals, the Taimyr Peninsula, Labrador, and certain other regions of mountain glaciation are entirely below the climatic snow line.

The elevation of the climatic snow line for a given year is determined from observations of the accumulation and melting of snow on glaciers, where the term “firn line” is used. The average elevation of the snow line over a period of years can be defined as (1) on mountain glaciers, the morphological boundary between the accumulation area, which is usually concave in profile, and the ablation area, which is usually convex; (2) the structural boundary between the area of conformably bedded snow and firn in the upper formations and the area where structured ice is dissected by the surface of melting in the lower formations (or, the structural boundary between the bergschrund area in the upper formations and the area of surfacial moraines in the lower formations); or (3) the average elevation of the surface of mountain glaciers, which approximates the elevation of the snow line.


Tronov, M. V. Voprosy gornoi gliatsiologii. Moscow, 1954.
Tronov, M. V. Faktory oledeneniia i razvitie lednikov. Tomsk, 1972.
Tushinskii. G. K. Ledniki, snezhniki, laviny Sovetskogo Soiuza. Moscow, 1963.

P. A. SHUMSKII [23–1879–]

snow line

[′snō ‚līn]
A transient line delineating a snow-covered area or altitude.
An area with more than 50% snow cover.
The altitude or geographic line separating areas in which snow melts in summer from areas having perennial ice and snow.

snow line

the altitudinal or latitudinal limit of permanent snow
References in periodicals archive ?
Ordinarily snapping a picture of the snow line through the dense fog of carbon monoxide would be impossible.
After dropping down below the snow line and re-zeroing the Schmidt-Rubin (it was about six inches off), I bashed my way back up the grade and found Aarne's Bronco.
It took us just over 20 minutes to drop down out of the high country to the edge of the snow line where patches of tussock grass became visible, protruding through the ice.
There are kookaburras in the trees and warnings about koalas and kangaroos above the snow line.
Our reason for this uncertainty was based largely on the fact that, according to some palaeoclimatic evidence, the snow line in the Zagros during the Pleistocene was at about 1200-1800 m a.
One afternoon we took a drive up to the snow line and I can't tell you how beautiful it was.
TREES: Protect young trees with thin bark from rodent damage by wrapping trunks with hardware cloth (1/4-inch openings) up to the expected snow line.
Was it well adjusted for generations of Buddhist monks to go and live abov e the snow line in the everlasting silence of the mountains?
Every year they died back to the snow line, forming "apple bushes," until they finally gave up.
Snow ought to have known this, having married Pamela Hansford-Johnson whose Proust Variations alone offer a working refutation of the Snow line.
Contract awarded for Snow line transition device power installation work
This was where the heavens opened as we climbed steeply into the snow line, the rain sometimes turning to sleet, and we were glad were were in a modern car with integrated sat nav, automatic wipers and good heating.