Lake Ice and 
Snow Science 

SNOW: Other Properties

Snow Albedo

Snow albedo changes as the state of the snow cover changes. New snow albedo is 0.90 and it decreases as the snow goes through the densification process or begins to melt.

The albedo effect of the snow-temperature feedback can be described as follows. If a snow covered area warms and the snow melts, the albedo decreases, more sunlight is absorbed, and the temperature tends to increase. The converse is also true: if snow forms, a cooling cycle happens. The intensity of the albedo effect depends on the magnitude of the change in albedo and the amount of insolation.

QUESTION: When will snow albedo be the highest? lowest?

Snow Water Equivalent (SWE)

Snow Water Equivalent (SWE) is the amount of water contained within the snowpack. It can be thought of as the depth of water that would theoretically result if you melted the entire snowpack instantaneously. Changes to the water equivalent snow depth result from snow accumulation and snow melt.

Snow water equivalent can be presented in units of kg/m³ or meters of depth of liquid water that would result from melting the snow. SWE is the product of depth and density:

SWE = depth (m) x density (kg/m³) (units: kg/m ²)
SWE = depth (m) x density (kg/m ³) / density of water (kg/m ³) (units: m)

(Remember: 1 cm³ (1 millilitre) has a mass of 1 gm or 1000 cm³ (1 litre) has a mass of 1000 grams (1 kilogram).)

QUESTION: What is the SWE of 15.7 cm of snow with a density of 0.175 gm/cm³?

See mean monthly snow depth and snow water equivalent for sites in Alaska.