(1) Growth of a cloud or precipitation particle by collision with supercooled liquid droplets that freeze wholly or partially on impact. (2) The process by which a layer of ice or snow builds on solid
objects such as overhead lines that are exposed to precipitation icing events.
Growth of a cloud or precipitation particle by the collision and union of a frozen particle (ice crystal or snowflake) with a supercooled liquid droplet which freezes on impact.
All processes that add mass to the snow cover or to a glacier, i.e., typically solid and liquid precipitation, ice deposition from atmospheric water vapour, wind-deposited snow, but also avalanches, e
tc. (opposite of ablation).
1. All processes that add to the mass of the glacier. 2. The mass gained by the operation of any of the processes of sense 1, expressed as a positive number. The main process of accumulation is snowfa
ll. Accumulation also includes deposition of hoar, freezing rain, solid precipitation in forms other than snow, gain of windborne snow, avalanching and basal accumulation (often beneath floating ice). Unless the rain freezes, rainfall does not constitute accumulation, nor does the addition of debris by avalanching, ashfall or similar processes.
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-d
eposited snow, and the freezing of rain within the snow pack.
The addition of ice and snow into a glacier system. This occurs through a variety of processes including precipitation, firnification, and wind transportation of snow into a glacier basin from an adja
cent area.
The process of building-up of a pack of snow, refrozen slush, meltwater and firn. Net accumulation for one year is the material left over at the end of the melt-season.
All processes by which snow, ice, or water in any form are added to a glacier, floating ice or snow cover. These include direct precipitation of snow, ice or rain, condensation of ice from vapour, and
transport of snow and ice to the glacier. Also used to express the quantity added by these processes.
That part of a glacier's surface, usually at higher elevations, on which there is net accumulation of snow, which subsequently turns into firn and then glacier ice.
Accumulation area is the upper region of a glacier where snow accumulation exceeds melting. A line that marks the limit on a mountain above which snow persists from one winter to the next is called th
e annual snowline, and this line on a glacier is called the firnline. Above the firnline, snow that falls each year packs down and changes into glacier ice as air is slowly forced out of it. This part of the glacier is its accumulation area where more snow falls each year than is lost by melting. Below the firnline is the ablation area, where melting predominates. A synonym of accumulation zone.
The ratio, often expressed as a percentage, of the area of the accumulation zone to the area of the glacier. The AAR is bounded between 0 and 1. On many glaciers it correlates well with the climatic m
ass balance. The likelihood that the climatic mass balance will be positive increases as the AAR approaches 1. Unless qualified by a different adjective, references to the AAR refer to the Annual AAR.