Climatological term referring to the mean, median, extreme minimum or extreme maximum extent of the ice edge in any given month or period based on observations over a number of years. Term should be p
receded by the word mean, median, minimum or maximum.
A lake that is located adjacent to the terminus of a glacier. Typically, these lakes form in bedrock basins scoured by the glacier. They enlarge as the glacier retreats. Sometimes they are dammed by a
n End or Recessional Moraine.
Sea ice terminology that describes a variable accumulation of pack or very close pack, covering hundreds of square kilometres and found in the same region every summer.
Excess ice that acts as cementation of the soil particles, typically within coarser permafrost sediments, such as in colluvial slopes or Rock Glaciers.
The ratio of the mass of ice per unit mass of dry air in a sample containing cloud ice and/or frozen precipitation. (Also called ice water mixing ratio.)
A process from which more ice particles are produced from existing ice crystals in clouds. Sometimes known as ice enhancement. The process is inferred from the observation that ice particle concentrat
ion often exceeds that of ice nuclei, sometimes by several orders of magnitude. Currently the following mechanisms are thought to be responsible for the ice multiplication phenomenon: 1) mechanical fracturing of ice crystals during evaporation; 2) shattering or partial fragmentation of large drops during freezing; and 3) ice splinter formation during the riming of ice particles (Hallett-Mossop process).
A long, thin ice crystal, axis coincident with the c axis of ice and with the cross section perpendicular to its long dimension being, at least in part, hexagonal. Ice needles grow in a narrow range o
f temperature near -4C and also at much lower temperatures, below -25 to -50C depending on ice supersaturation.
Any of several devices for counting atmospheric particles that serve as heterogeneous ice nuclei that are suited by composition to catalyze the formation of ice crystals in the atmosphere. The devices
operate on varied principles, include means to cool and moisturize the air within a chamber or over a nucleus-collection filter, and are intended to measure the number concentration of ice nuclei that form ice crystals as a function of temperatures that would occur in subzero tropospheric clouds (thus, 0 to near -40C). The product is the nucleation activity temperature spectrum. Some, but by no means all, types of ice nuclei counters are designed to attempt to replicate supersaturations that occur where ice crystals form in natural tropospheric clouds. (Abbreviated IN counter.)