Temperature gradient is the difference in snow temperature across a given vertical range in the snowpack. In practice, it is usually expressed in degrees celsius per 10 centimetres.
The strength of temperature gradient dictates the rate of sublimation and deposition processes in the snowpack. The stronger the temperature gradient, the more rapid the sublimation and deposition.
As a general rule, a temperature gradient less than 1 C per 10 cm contributes to strengthening bonds between snow grains. This process is called rounding.
A temperature gradient greater than 1 C per 10 cm weakens bonds between snow grains. This is called faceting.