This data set contains a global (excluding Antarctica) 1 km map of permafrost zonation. It is an estimate of to what degree permafrost exists in a region nearly everywhere, or only in the most favorable conditions. These local conditions affecting permafrost occurrence will partly exhibit regional trends (e.g. mean snow cover characteristics or continentality), partly vary over typical distances on the order of several km (e.g. shaded or sun-exposed side of a mountain), and partly over tens to hundreds of meters (e.g. snow drift, vegetation, ground material). These conditions need to be assessed during interpretation, depending on the intended purpose of using the PZI map. This product is likely to be most valuable in remote regions where only sparse reliable information exists.
Key Strengths:
- Provides a global map of permafrost occurrence for comparison with model predictions or for other studies
Key Limitations:
- Not purely observational data; the permafrost map is itself dependent on models, including the permafrost model and the model used to generate the reanalysis, from which the temperatures are taken (and combined with temperatures from CRU)
Expert Developer Guidance
The following was contributed by Stephan Gruber (U Zurich), April, 2012:
This data set contains a global (excluding Antarctica) 1 km map of permafrost zonation. The accompanying publicatios points out important limitations that exist in such products and that may be relevant when used for validating other models. The Permafrost Zonation Index (PZI) or a corresponding map color indicates, to what degree permafrost exists only in the most favorable conditions (yellow) or nearly everywhere (blue). These local conditions affecting permafrost occurrence will partly exhibit regional trends (e.g. mean snow cover characteristics or continentality), partly vary over typical distances on the order of several km (e.g. shaded or sun-exposed side of a mountain), and partly over tens to hundreds of meters (e.g. snow drift, vegetation, ground material). These conditions need to be assessed during interpretation, depending on the intended purpose of using the PZI map. This product is likely to be most valuable in remote regions where only sparse reliable information exists. The accompanying publication [Key Publication #1 below, Gruber et al., 2012] points to the importance of heterogeneity and uncertainty in the derivation and use of such permafrost zonation maps.#