PERICLIMv1.0: A model deriving palaeo-air temperatures from thaw depth in past permafrost regions

• Main Authors: Uxa, Tomáš, Křížek, Marek, Hrbáček, Filip
• Format: Text
• Language: English
• Published: 2020
• Subjects: permafrost
• Online Access: https://doi.org/10.5194/gmd-2020-5; https://gmd.copernicus.org/preprints/gmd-2020-5/

Periglacial features are among the most common relics of colder climates, which repetitively occurred throughout the Quaternary, and, as such, they are widespread archives of past conditions. Climatic controls on most periglacial features, however, remain poorly established, and thus empirical palaeo-climatic reconstructions based on them are far from reliable. This study introduces and evaluates a new simple inverse modelling scheme PERICLIMv1.0 (PERIglacial CLIMate) that aims to overcome these flaws through deriving the palaeo-air temperature characteristics coupled with the thickness of the palaeo-active layer, which can be recognized in many relict permafrost-related features. The evaluation against modern temperature records showed that the model reproduces air temperature characteristics, such as mean annual air temperature, mean air temperature of the warmest and coldest month and of the thawing and freezing season, with a mean error of ≤ 0.5 °C. Besides, air thawing and freezing indices both depart on average by 6 %, whereas the length of the thawing and freezing season tends to be on average underestimated and overestimated by 10 % and 4 %, respectively. The high model success rate is promising and suggests that it could become a powerful tool for reconstructing Quaternary palaeo-environments across vast areas of mid-latitudes where relict periglacial assemblages frequently occur, but their full potential remains to be exploited.