Cryosphere glossary
vane
instrument used to measure wind direction; also called wind vane.
vapor pressure
the pressure exerted by water vapor molecules in a given volume of air.
vein ice
a comprehensive term for ice of any origin occupying cracks in permafrost.
very close pack ice
pack ice in which the floes are tightly packed but not frozen together, with very little, if any, sea water visible; ice cover practically 10/10th.
very open pack ice
pack ice composed of loose, widely spaced floes; ice cover 1/10th to 3/10th.
virga
precipitation that evaporates before reaching the ground.
viscosity
a measure of a fluids resistance to flow; can be thought of as a measure of fluid friction.
visibility
the greatest distance that prominent objects can be seen and identified by unaided, normal eyes.
visualization
Tools that provide visual images of data on-the-fly.
volumetric (total) water content
the ratio of the volume of the water and ice in a sample to the volume of the whole sample, expressed as a fraction (or, less commonly, as a percentage).
volumetric heat capacity
the amount of heat required to raise the temperature of a unit volume of a substance by one degree.
volumetric latent heat of fusion
the amount of heat required to melt all the ice (or freeze all the pore water) in a unit volume of soil or rock.
warm front
the forward edge of an advancing warm air mass that is displacing cooler air in its path.
warm low
at a given level in the atmosphere, any low that is generally characterized by warmer air near its center than around its periphery; the opposite of a cold low.
water sky
the dark appearance of the underside of a cloud layer when it is over a surface of open water; it is darker than land sky, and much darker than ice blink or snow blink.
water vapor
water substance in vapor (gaseous) form; one of the most important of all constituents of the atmosphere.
waterbody encircling a palsa
a water-filled depression surrounding a palsa.
watermelon snow
snow with red algae growing on it.
wave ogives
ogives that show some vertical relief on a glacier; usually the dark bands are in the hollows and the light bands are in the ridges; form at the base of steep, narrow ice falls.
weather
the state of the atmosphere, mainly with respect to its effects upon life and human activities; distinguished from climate by focusing on short-term (minutes to about 15 days) variations of the atmosphere state.