Tests whether continuous frozen / permafrost material occurs within
the upper max_top_cm. Two alternative paths qualify per WRB
2022:
Permafrost temperature: a layer at top_cm <=
max_top_cm(default 100) withpermafrost_temp_C <= max_temp_C(default 0 C).Designation pattern: a layer at top_cm <=
max_top_cmwith designation containing suffix"f"(frozen) or matching"^Cf"/"perma". A site that declares the Canadian notation (site$designation_system = "cssc") writes a frozen layerz; the New Zealand and Australian notations have no frozen suffix, so there only"perma"counts. Used as a fallback when the temperature field is not in the pedon (typical of legacy survey data).
Either path qualifies. Diagnostic of Cryosols. When neither passes and
the site has a soil temperature regime warmer than gelic (cryic, frigid,
mesic, thermic, hyperthermic or an iso form;
site$soil_temperature_regime), the answer is no: those regimes
have no permafrost (KST 13, Ch. 3, p. 50).
Arguments
- pedon
A
PedonRecord.- max_top_cm
Maximum top depth (cm) (default 100).
- max_temp_C
Maximum mean annual permafrost-zone temperature (deg C) for the temperature path (default 0).