Parameter Tree:
EARTH SCIENCE > CRYOSPHERE > FROZEN GROUND > CRYOSOLS

Definition:
Soil formed in either mineral or organic materials having permafrost either
within 1 m below the surface or, if the soil is strongly cryoturbated, with 2 m
below the surface, and having a mean annual ground temperature below 0 deg C.


Reference:
From the National Snow and Ice Data Center (NSIDC):http://nsidc.org