Typical Densities of Snow
Snow can be considered as ice crystals precipitating from the atmosphere and later undergoing changes (metamorphose, melting or sublimation) on the surface. Neither particles of snow (snowflakes) nor how they accumulate on the surface or change over time are unique which justifies why physical properties of snow can vary considerably from sample to sample or over time. Typical densities of snow can vary from about 50 kg m-3 for new snow to about density of ice (917 kg m-3) for glacier ice. Between these values lie densities of other types of snow like Névé, firn and depth hoar. Névé is a young snow that has partially experienced melting and refreezing which causes it to become denser than before. Névé turns into older and slightly denser firn after surviving a full season of ablation where firn itself eventually becomes glacier ice, the long-lived and compacted ice that glaciers are composed of. Depth hoar also called sugar snow refers to large crystals resulted from deposition (the reverse of sublimation) of uprising water vapor onto present snow crystals inside a snowpack.