Statistical Forecasting of Current and Future Circum-Arctic Ground Temperatures and Active Layer Thickness

• Published in: Geophysical Research Letters
• Main Authors: Aalto, J., Karjalainen, O., Hjort, J., Luoto, M.
• Other Authors: Department of Geosciences and Geography, BioGeoClimate Modelling Lab
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2019
• Subjects: ensemble modeling; permafrost; climate change; uncertainty; Arctic; ground thermal regime; SPECIES DISTRIBUTION MODELS; CLIMATE-CHANGE; PERMAFROST REGION; SOUTHERN NORWAY; THERMAL REGIME; DYNAMICS; DEGRADATION; ICE; INSIGHTS; 114 Physical sciences; 1172 Environmental sciences; Norway; Active layer thickness; Climate change; Ice
• Online Access: http://hdl.handle.net/10138/307286

Mean annual ground temperature (MAGT) and active layer thickness (ALT) are key to understanding the evolution of the ground thermal state across the Arctic under climate change. Here a statistical modeling approach is presented to forecast current and future circum-Arctic MAGT and ALT in relation to climatic and local environmental factors, at spatial scales unreachable with contemporary transient modeling. After deploying an ensemble of multiple statistical techniques, distance-blocked cross validation between observations and predictions suggested excellent and reasonable transferability of the MAGT and ALT models, respectively. The MAGT forecasts indicated currently suitable conditions for permafrost to prevail over an area of 15.1 +/- 2.8 x 10(6) km(2). This extent is likely to dramatically contract in the future, as the results showed consistent, but region-specific, changes in ground thermal regime due to climate change. The forecasts provide new opportunities to assess future Arctic changes in ground thermal state and biogeochemical feedback. Peer reviewed